Coronavirus and influenza compositions and methods of use thereof

Abstract

Disclosed herein are compositions and methods for eliciting an immune response against both influenza virus and coronavirus. Provided herein are compositions and methods of use thereof, the compositions comprising (a) a coronavirus S (CoV S) glycoprotein in the form of a detergent-core nanoparticle, where the detergent is a non-ionic detergent; (b) at least three hemagglutinin (HA) glycoproteins, where each HA glycoprotein is from a different influenza strain; and (c) a pharmaceutically acceptable buffer.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Patent Application No. 63 / 184,727, filed May 5, 2021, U.S. Patent Application No. 63 / 193,356, filed May 26, 2021, U.S. Patent Application No. 63 / 255,685, filed October 14, 2021, and U.S. Patent Application No. 63 / 332,537, filed April 19, 2022. Each of the foregoing patent documents is incorporated herein by reference in its entirety.

[0002] Description of electronically submitted text files The contents of the text file submitted electronically herewith are incorporated by reference in their entirety herein: Computer-readable copy of the Sequence Listing (Filename: NOVV_093_01WO_SeqList_ST25.txt, Recorded on: April 22, 2022, File Size: 976 KB).

[0003] The present disclosure relates to compositions and methods for eliciting an immune response against both influenza viruses and coronaviruses. [Background technology]

[0004] Influenza and coronavirus disease 2019 (COVID-19) are life-threatening illnesses caused by the influenza virus and the acute respiratory coronavirus type 2 (SARS-CoV-2) virus, respectively. The case fatality rate for patients diagnosed with influenza is approximately 0.1%, while the case fatality rate for patients diagnosed with COVID-19 ranges from 0.2% to 7.7%.

[0005] The development of vaccines to prevent or reduce these life-threatening infectious diseases is desirable. However, the development of human vaccines remains challenging due to the highly sophisticated evasion mechanisms of pathogens and the difficulty of stabilizing vaccines. Optimally, a vaccine must induce antibodies that both block or neutralize infectious agents and remain stable in a variety of environments, including those where refrigeration is not possible. The combination of two antigens from two pathogens in a single vaccine composition is particularly challenging, as the antigens may interact with each other to prevent a sufficient immune response to either pathogen. Summary of the Invention

[0006] The present disclosure provides compositions and methods for eliciting an immune response against both influenza viruses and coronaviruses.

[0007] Provided herein is an immunogenic composition comprising: (a) a coronavirus S (CoV S) glycoprotein in the form of a detergent-core nanoparticle, where the detergent is a non-ionic detergent; (b) at least three hemagglutinin (HA) glycoproteins, where each HA glycoprotein is from a different influenza strain; and (c) a pharma- ceutically acceptable buffer. In an embodiment, the at least three HA glycoproteins are in a form selected from the group consisting of: (a) a detergent-core nanoparticle comprising hemagglutinin (HA), (b) HaSMaN (hemagglutinin saponin matrix nanoparticle), (c) an inactivated whole influenza virus, (d) a hemagglutinin composition extracted from an influenza virus, an optional influenza split virion composition or a subunit influenza composition, and any combination thereof. In an embodiment, the at least one HA glycoprotein is in the form of a detergent-core nanoparticle comprising HA, and the at least one HA glycoprotein is in the form of HaSMaN. In an embodiment, the hemagglutinin glycoprotein of the detergent-core nanoparticle is from an influenza B strain. In an embodiment, the hemagglutinin glycoprotein of the detergent-core nanoparticle is from an influenza A strain. In an embodiment, the detergent-core nanoparticle is a trypsin-resistant nanoparticle. In an embodiment, HaSMaN is a trypsin-resistant nanoparticle. In an embodiment, each HA glycoprotein is from a different influenza strain. In an embodiment, the immunogenic composition comprises up to 4, up to 5, up to 6, up to 7, up to 8, up to 9, or up to 10 HA glycoproteins. In an embodiment, each HA glycoprotein is in the form of a nanoparticle. In an embodiment, each nanoparticle comprises HA glycoprotein from a single influenza strain. In an embodiment, each nanoparticle is a detergent-core nanoparticle or a HaSMaN. In an embodiment, the immunogenic composition comprises an adjuvant. In an embodiment, the adjuvant is a saponin adjuvant.In an embodiment, the saponin adjuvant comprises at least two ISCOM particles, a first ISCOM particle comprising fraction A of Quillaja Saponaria Molina and not fraction C of Quillaja Saponaria Molina, and a second ISCOM particle comprising fraction C of Quillaja Saponaria Molina and not fraction A of Quillaja Saponaria Molina. In an embodiment, fraction A of Quillaja Saponaria Molina constitutes 50-96% by weight of the combined weight of fraction A of Quillaja Saponaria Molina and fraction C of Quillaja Saponaria Molina in the adjuvant, with fraction C of Quillaja Saponaria Molina making up the remainder. In an embodiment, Fraction A of Quillaja Saponaria Molina and Fraction C of Quillaja Saponaria Molina constitute about 85% and about 15% by weight, respectively, of the combined weight of Fraction A of Quillaja Saponaria Molina and Fraction C of Quillaja Saponaria Molina in the adjuvant. In an embodiment, the immunogenic composition comprises about 50 μg or about 75 μg of saponin adjuvant. In an embodiment, the detergent is PS80. In an embodiment, the influenza strain is of a subtype selected from the group consisting of H1, H2, H3, H4, H5, H6, H7, H8, H9, H10, H11, H12, H13, H14, H15, H16, H17, and H18. In embodiments, the pharma- ceutically acceptable buffer comprises: (i) about 25 mM sodium phosphate; (ii) about 150 mM sodium chloride; (iii) about 100 mM arginine hydrochloride; and (iv) about 5% trehalose, wherein the pH of the composition is about 7.5.In embodiments, the CoV S glycoprotein comprises: (i) an S1 subunit with an inactivated furin cleavage site (the S1 subunit comprises an N-terminal domain (NTD), a receptor binding domain (RBD), subdomains 1 and 2 (SD1 / 2), and the inactivated furin cleavage site has the amino acid sequence of QQAQ (SEQ ID NO: 7), and the NTD optionally comprises: (a) amino acids 56, 57, 131, 132, 144, 145, 228, 229, 230, 231, 234, 235, 236, 237, 238, 239, 240, and the like); (b) a deletion of one or more amino acids selected from the group consisting of amino acids 132 and combinations thereof; (b) an insertion of one, two, three, or four amino acids beginning at amino acid 132; and (c) a mutation of one or more amino acids selected from the group consisting of amino acids 5, 6, 7, 13, 51, 53, 56, 57, 62, 63, 67, 82, 125, 129, 131, 132, 133, 139, 143, 144, 145, 177, 200, 201, 202, 209, 229, 233, 240, 245, and combinations thereof. wherein the RBD optionally comprises one or more amino acid mutations selected from the group consisting of amino acids 333, 404, 419, 426, 439, 440, 464, 465, 471, 481, 488, and combinations thereof, and wherein the SD1 / 2 domain optionally comprises one or more amino acid mutations selected from the group consisting of 557, 600, 601, 642, 664, 668, and combinations thereof; and (ii) an S2 subunit, wherein amino acids 973 and 974 are proline. and the S2 subunit optionally comprises one or more modifications selected from the group consisting of: (a) a deletion of one or more amino acids from 676-685, 676-702, 702-711, 775-793, 806-815, and combinations thereof; (b) a mutation of one or more amino acids selected from the group consisting of 688, 703, 846, 875, 937, 969, 1014, 1058, 1105, and 1163, and combinations thereof; (c) a deletion of one or more amino acids from TMCT, wherein the amino acids of the CoV S glycoprotein are numbered relative to a polypeptide having the sequence of SEQ ID NO:2.In embodiments, the CoV S glycoprotein comprises or consists of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% identity to any one of SEQ ID NOs: 86-89, 105, 106, 112-115, and 164-168. In embodiments, the CoV S glycoprotein comprises a sequence that is at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% identical to SEQ ID NO: 87. In embodiments, the immunogenic composition comprises from about 1 μg to about 50 μg of CoV S glycoprotein and from about 5 μg to about 60 μg of hemagglutinin per strain. In embodiments, the immunogenic composition comprises about 20 μg to about 50 μg of CoV S glycoprotein and about 24 μg to about 40 μg of hemagglutinin per strain. In embodiments, the immunogenic composition comprises about 3 μg, about 5 μg, about 25 μg, about 22.5 μg, about 7.5 μg, or about 2.5 μg of coronavirus S glycoprotein. In embodiments, the immunogenic composition comprises about 5 μg, about 10 μg, about 24 μg, about 25 μg, about 26 μg, about 27 μg, about 28 μg, about 29 μg, about 30 μg, about 31 μg, about 32 μg, about 33 μg, about 34 μg, about 35 μg, about 36 μg, about 37 μg, about 38 μg, about 39 μg, about 40 μg, or about 60 μg of hemagglutinin per strain.

[0008] In embodiments, provided herein is a method of stimulating an immune response to SARS-CoV-2, a heterogeneous SARS-CoV-2 strain, influenza virus, or a combination thereof in a subject, comprising administering any of the immunogenic compositions described herein. In embodiments, the subject is administered a first dose on day 0 and a booster dose on day 56. In embodiments, the immunogenic composition is administered intramuscularly. In embodiments, a single dose of the immunogenic composition is administered. In embodiments, the heterogeneous SARS-CoV-2 strain is selected from the group consisting of a Cal.20C SARS-CoV-2 strain, a P.1 SARS-CoV-2 strain, a B.1.351 SARS-CoV-2 strain, a B.1.1.7 SARS-CoV-2 strain, a SARS-CoV-2 B.1.617.2 strain, a B.1.525 strain, a B.1.526 strain, a B.1.617.1 strain, a C.37 strain, a B.1.621 strain, or a SARS-CoV-2 Omicron strain. In embodiments, the efficacy of the immunogenic composition for preventing coronavirus disease 19 (COVID-19) is up to about 2 months, up to about 2.5 months, up to about 3 months, up to about 3.5 months, up to about 4 months, up to about 4.5 months, up to about 5 months, up to about 5.5 months, up to about 6 months, up to about 6.5 months, up to about 7 months, up to about 7.5 months, up to about 8 months, up to about 8.5 months, up to about 9 months, up to about 9.5 months, up to about 10 months, up to about 10.5 months, up to about 11 months, up to about 12 months, up to about 13 months, up to about 14 months, up to about 15 months, up to about 16 months, up to about 17 months, up to about 18 months, up to about 19 months, up to about 20 months, up to about 21 months, up to about 22 months, up to about 23 months, up to about 24 months, up to about 25 months, up to about 26 months, up to about 27 months, up to about 28 months, up to about 29 months, up to about 30 months, up to about 31 months, up to about 32 months, up to about 33 months, up to about 34 months, up to about 35 months, up to about 36 months, up to about 37 months, up to about 38 months, up to about 39 months, up to about 40 months, up to about 41 months, up to about 42 months, up to about 43 months, up to about 44 months, up to about 45 months, up to about 46 months, up to about 47 months, up to about 48 months, up to about 49 months, up to about 50 months, up to about 51 months, up to about 52 months, up to about 5 At least about 50%, at least about 55%, at least about 60%, at least about 65%, at least about 70%, at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 91%, at least about 92%, at least about 93%, at least about 94%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, or at least about 99%, or about 100% for about 11.5 months, or up to about 12 months.In embodiments, the efficacy of the immunogenic composition for preventing coronavirus disease 19 (COVID-19) is up to about 2 months, up to about 2.5 months, up to about 3 months, up to about 3.5 months, up to about 4 months, up to about 4.5 months, up to about 5 months, up to about 5.5 months, up to about 6 months, up to about 6.5 months, up to about 7 months, up to about 7.5 months, up to about 8 months, up to about 8.5 months, up to about 9 months, up to about 9.5 months, up to about 10 months, up to about 10.5 months, up to about 11 months, up to about 11.5 months, up to about 12 months, up to about 13 months, up to about 14 months, up to about 15 months, up to about 16 months, up to about 17 months, up to about 18 months, up to about 19 months, up to about 20 months, up to about 21 months, up to about 22 months, up to about 23 months, up to about 24 months, up to about 25 months, up to about 26 months, up to about 27 months, up to about 28 months, up to about 29 months, up to about 30 months, up to about 31 months, up to about 32 months, up to about 33 months, up to about 34 months, up to about 35 months, up to about 36 months, up to about 37 months, up to about 38 months, up to about 39 months, up to about 40 months, up to about 41 months, up to about 42 months, up to about 43 months, up to about 44 months, up to about 45 months, up to about 46 months, up to about 47 months, up to about 48 months, up to about 49 months, up to about 50 months, up to about 51 months, up to about Within a period of about 12 months, or up to about 12 months, the immunogenic composition is about 50% to about 99%, about 50% to about 95%, about 50% to about 90%, about 50% to about 85%, about 50% to about 80%, about 60% to about 99%, about 60% to about 95%, about 60% to about 90%, about 60% to about 85%, about 60% to about 80%, about 40% to about 99%, about 40% to about 95%, about 40% to about 90%, about 40% to about 85%, about 40% to about 80%, about 40% to about 75%, about 40% to about 70%, about 40% to about 65%, about 40% to about 55%, or about 40% to about 50%. In embodiments, a prefilled syringe comprising any of the immunogenic compositions described herein is provided. [Brief description of the drawings]

[0009] [Figure 1] Schematic representation of the wild-type amino acid sequence of the SARS-CoV-2 spike (S) protein (SEQ ID NO: 1). The furin cleavage site RRAR (SEQ ID NO: 6) is highlighted in bold and the signal peptide is underlined. [Diagram 2] , purification of CoV S polypeptides BV2364, BV2365, BV2366, BV2367, BV2368, BV2369, BV2373, BV2374, and BV2375. The data reveal that BV2365 (SEQ ID NO:4) and BV2373 (SEQ ID NO:87), which contain an inactive furin cleavage site with the amino acid sequence QQAQ (SEQ ID NO:7), are expressed as single chains (S0). In contrast, CoV S polypeptides containing an intact furin cleavage site (e.g., BV2364, BV2366, and BV2374) are cleaved, as evidenced by the presence of cleavage product S2. [Diagram 3] The primary structure of the BV2373 CoV S polypeptide is shown, as well as the modifications to the furin cleavage site, K986P and V987P. [Figure 4] Purification of wild-type CoV S polypeptide and CoV S polypeptides BV2365 and BV2373 is shown. [Diagram 5] Schematic diagram of coronavirus spike (S) protein (SEQ ID NO:86) (BV2373). The furin cleavage site QQAQ (SEQ ID NO:7) is single underlined, and the K986P and V987P mutations are double underlined. [Figure 6] A shows the primary structure of the wild-type SARS-CoV-2 S polypeptide including the signal peptide, numbered relative to SEQ ID NO: 1. B shows the primary structure of the wild-type SARS-CoV-2 S polypeptide without the signal peptide, numbered relative to SEQ ID NO: 2. [Figure 7] Examples of transmission electron microscopy (TEM) images of influenza HA detergent core nanoparticles alone (left), saponin adjuvant alone (center) (i.e., 85% fraction AISCOM matrix and 15% fraction CISCOM matrix), and the combination of HA nanoparticles with saponin adjuvant to form hemagglutinin saponin matrix nanoparticles (HaSMaN) (right) are shown. [Figure 8A] Immune responses to SARS-CoV-2 spike glycoprotein and influenza hemagglutinin in ferrets immunized with qNIV / CoV2373 combination vaccine. Groups of male and female ferrets (n=6 / group) were immunized with 15μg or 60μg hemagglutinin (HA) per strain and 5μg CoV2373 in combination with 50μg saponin adjuvant. Controls were immunized with 15μg or 60μg HA or 5μg CoV22373 per strain in combination with 50μg saponin adjuvant. All groups were dosed twice, 21 days apart. Red triangles indicate serum collection dates. [Figure 8B]Immune responses against SARS-CoV-2 spike glycoprotein and influenza hemagglutinin in ferrets immunized with qNIV / CoV2373 combination vaccine. Human angiotensin-converting enzyme-2 (hACE2) receptor blocking antibody titers. Hemagglutinin inhibitory antibody (HAI) titers are measured 21 days after the first dose and 14 days after the booster (study day 35). Bar graphs show geometric mean titers (GMT) and error bars indicate 95% confidence intervals. [Figure 8C] Immune responses against SARS-CoV-2 spike glycoprotein and influenza hemagglutinin in ferrets immunized with the qNIV / CoV2373 combination vaccine. A / Kansas / 14 / 2017. Bar graphs show geometric mean titers (GMTs) and error bars indicate 95% confidence intervals. [Figure 8D] Immune responses against SARS-CoV-2 spike glycoprotein and influenza hemagglutinin in ferrets immunized with the qNIV / CoV2373 combination vaccine. A / Brisbane / 02 / 2018. Bar graphs show geometric mean titers (GMTs) and error bars indicate 95% confidence intervals. [Figure 8E] Immune responses against SARS-CoV-2 spike glycoprotein and influenza hemagglutinin in ferrets immunized with the qNIV / CoV2373 combination vaccine. B / Phuket / 3070 / 2013. Bars show geometric mean titers (GMTs) and error bars indicate 95% confidence intervals. [Figure 8F] Immune responses against SARS-CoV-2 spike glycoprotein and influenza hemagglutinin in ferrets immunized with the qNIV / CoV2373 combination vaccine, B / Maryland / 15 / 2016. Bars show geometric mean titers (GMTs) and error bars show 95% confidence intervals. [Figure 9A]Figure 1. Immune responses and receptor-blocking antibodies against SARS-CoV-2 spike glycoprotein in hamsters immunized with qNIV / CoV2373 combination vaccine. Groups of male and female hamsters (n=5-6 per group) were immunized with combinations of 2.5 or 10 μg hemagglutinin (HA) / strain with 1 or 5 μg CoV2373 with 15 μg saponin adjuvant. Comparators were immunized with 2.5 or 10 μg HA / strain or 1 or 5 μg CoV2373 with 15 μg saponin adjuvant. Animals were immunized by the intramuscular route (IM) with two doses spaced 14 days apart. The placebo group received formulation buffer. Serum was collected for analysis at the times indicated by red triangles. Immunized and placebo animals were infected by the intranasal (IN) route with 2.0 × 104 pfu of SARS-CoV-2 on day 21 after the second immunization. Oral swabs were collected on days 2, 4, and 7 post-infection (dpi, blue triangles). Bronchoalveolar lavage fluid and lung samples were taken at 7 dpi (black triangles). [Figure 9B] Figure 1. Immune response and receptor-blocking antibodies against SARS-CoV-2 spike glycoprotein in hamsters immunized with qNIV / CoV2373 combination vaccine. Anti-spike IgG titers 14 days after the first dose. Bar graphs show group geometric mean titers (GMT) and error bars show 95% confidence intervals (95% CI). Values ​​for individual animals are indicated by colored symbols. Horizontal black dashed line indicates limit of detection (LOD). [Figure 9C] Immune responses and receptor-blocking antibodies against SARS-CoV-2 spike glycoprotein in hamsters immunized with qNIV / CoV2373 combination vaccine. Anti-spike IgG titers 14 days after booster (study day 28). Bar graphs show group geometric mean titers (GMT) and error bars show 95% confidence intervals (95% CI). Individual animal values ​​are indicated by colored symbols. Horizontal black dashed line indicates limit of detection (LOD). [Figure 9D]Figure 1. Immune response and receptor-blocking antibodies against SARS-CoV-2 spike glycoprotein in hamsters immunized with qNIV / CoV2373 combination vaccine. Human ACE-2 (hACE2) receptor-blocking antibody titers 14 days after the first dose. Bar graphs show group geometric mean titers (GMT) and error bars show 95% confidence intervals (95% CI). Values ​​for individual animals are indicated by colored symbols. Horizontal black dashed line indicates limit of detection (LOD). [Figure 9E] Figure 1. Immune response and receptor-blocking antibodies against SARS-CoV-2 spike glycoprotein in hamsters immunized with qNIV / CoV2373 combination vaccine. Human ACE-2 (hACE2) receptor-blocking antibody titers 14 days after booster (study day 28). Bar graphs show group geometric mean titers (GMT) and error bars show 95% confidence intervals (95% CI). Individual animal values ​​are indicated by colored symbols. Horizontal black dashed line indicates limit of detection (LOD). [Figure 10A] Figure 8 shows immune responses to influenza HA in hamsters immunized with qNIV / CoV2373 combination vaccine. Groups of hamsters were immunized with the qNIV / CoV2373 vaccine combination or the component vaccines shown in Figure 8A. Serum was analyzed for hemagglutinin inhibitory antibody (HAI) titers 14 days after a single dose. A / Kansas / 14 / 2017. Bar graphs show geometric mean titers and error bars indicate 95% confidence intervals. [Figure 10B] Groups of hamsters were immunized with the qNIV / CoV2373 vaccine combination or the component vaccines shown in Figure 8A. Serum was analyzed for hemagglutinin inhibitor antibody (HAI) titers 14 days after boost (study day 28). A / Kansas / 14 / 2017. Bar graphs show geometric mean titers and error bars indicate 95% confidence intervals. [Figure 10C]Groups of hamsters were immunized with the qNIV / CoV2373 vaccine combination or the component vaccines shown in Figure 8A. Serum was analyzed for hemagglutinin inhibitory antibody (HAI) titers 14 days after a single dose. A / Brisbane / 02 / 2018. Bar graphs show geometric mean titers and error bars indicate 95% confidence intervals. [Figure 10D] Groups of hamsters were immunized with the qNIV / CoV2373 vaccine combination or the component vaccines shown in Figure 8A. Serum was analyzed for hemagglutinin inhibitory antibody (HAI) titers 14 days after boost (study day 28). A / Brisbane / 02 / 2018. Bar graphs show geometric mean titers and error bars indicate 95% confidence intervals. [Figure 10E] Groups of hamsters were immunized with the qNIV / CoV2373 vaccine combination or the component vaccines shown in Figure 8A. Sera were analyzed for hemagglutinin inhibitory antibody (HAI) titers 14 days after a single dose. B / Phuket / 3070 / 2013. Bar graphs show geometric mean titers, error bars indicate 95% confidence intervals. [Figure 10F] Groups of hamsters were immunized with the qNIV / CoV2373 vaccine combination or the component vaccines shown in Figure 8A. Sera were analyzed for hemagglutinin inhibitor antibody (HAI) titers 14 days after boost (study day 28). B / Phuket / 3070 / 2013. Bar graphs show geometric mean titers, error bars indicate 95% confidence intervals. [Figure 10G] Groups of hamsters were immunized with the qNIV / CoV2373 vaccine combination or the component vaccines shown in Figure 8A. Sera were analyzed for hemagglutinin inhibitory antibody (HAI) titers 14 days after a single dose. B / Maryland / 15 / 2016. Bar graphs show geometric mean titers and error bars indicate 95% confidence intervals. [Figure 10H]Groups of hamsters were immunized with the qNIV / CoV2373 vaccine combination or the component vaccines shown in Figure 8A. Sera were analyzed for hemagglutinin inhibitor antibody (HAI) titers 14 days after boost (study day 28). B / Maryland / 15 / 2016. Bar graphs show geometric mean titers and error bars indicate 95% confidence intervals. [Figure 11A] Figure 8 shows influenza virus neutralizing antibodies in hamsters immunized with the qNIV / CoV2373 combination vaccine. Groups of hamsters were immunized with the qNIV / CoV2373 combination or the component vaccines shown in Figure 8A. Virus neutralizing titers in response to A / Kansas / 14 / 2017 were determined 14 days after a single dose. [Figure 11B] Figure 8 shows influenza virus neutralizing antibodies in hamsters immunized with qNIV / CoV2373 combination vaccine. Groups of hamsters were immunized with qNIV / CoV2373 combination or component vaccines as shown in Figure 8A. Virus neutralization titers in response to A / Kansas / 14 / 2017 were determined 14 days after booster (study day 28). Bar graphs show geometric mean titers (GMT) and error bars show 95% confidence intervals. Horizontal dashed lines indicate limits of detection (LOD). [Figure 11C] Figure 8 shows influenza virus neutralizing antibodies in hamsters immunized with qNIV / CoV2373 combination vaccine. Groups of hamsters were immunized with qNIV / CoV2373 combination or component vaccines as shown in Figure 8A. Virus neutralization titers in response to A / Brisbane. / 02 / 2018 were determined 14 days after a single dose. Bar graphs show geometric mean titers (GMT) and error bars show 95% confidence intervals. Horizontal dashed lines indicate limits of detection (LOD). [Figure 11D]Figure 8 shows influenza virus neutralizing antibodies in hamsters immunized with qNIV / CoV2373 combination vaccine. Groups of hamsters were immunized with qNIV / CoV2373 combination or component vaccines as shown in Figure 8A. Virus neutralizing titers in response to A / Brisbane. / 02 / 2018 were determined 14 days after booster (study day 28). Bar graphs show geometric mean titers (GMT) and error bars show 95% confidence intervals. Horizontal dashed lines indicate limits of detection (LOD). [Figure 11E] Figure 8 shows influenza virus neutralizing antibodies in hamsters immunized with qNIV / CoV2373 combination vaccine. Groups of hamsters were immunized with qNIV / CoV2373 combination or component vaccines as shown in Figure 8A. Virus neutralizing titers in response to B / Phuket / 3073 / 2013 were determined 14 days after a single dose. Bar graphs show geometric mean titers (GMT) and error bars show 95% confidence intervals. Horizontal dashed lines show limits of detection (LOD). [Figure 11F] Figure 8 shows influenza virus neutralizing antibodies in hamsters immunized with qNIV / CoV2373 combination vaccine. Groups of hamsters were immunized with qNIV / CoV2373 combination or component vaccines as shown in Figure 8A. Virus neutralizing titers in response to B / Phuket / 3073 / 2013 were determined 14 days after booster (study day 28). Bar graphs show geometric mean titers (GMT) and error bars show 95% confidence intervals. Horizontal dashed lines indicate limits of detection (LOD). [Figure 11G] Figure 8 shows influenza virus neutralizing antibodies in hamsters immunized with qNIV / CoV2373 combination vaccine. Groups of hamsters were immunized with qNIV / CoV2373 combination or component vaccines as shown in Figure 8A. Virus neutralizing titers in response to B / Maryland / 15 / 2016 were determined 14 days after a single dose. Bar graphs show geometric mean titers (GMT) and error bars show 95% confidence intervals. Horizontal dashed lines show limits of detection (LOD). [Figure 11H]Figure 8 shows influenza virus neutralizing antibodies in hamsters immunized with qNIV / CoV2373 combination vaccine. Groups of hamsters were immunized with qNIV / CoV2373 combination or component vaccines as shown in Figure 8A. Virus neutralizing titers in response to B / Maryland / 15 / 2016 were determined 14 days after booster (study day 28). Bar graphs show geometric mean titers (GMT) and error bars show 95% confidence intervals. Horizontal dashed lines indicate limits of detection (LOD). [Figure 12A] We show that the qNIV / CoV2373 vaccine combination elicits antibodies that bind to highly conserved cryptic epitopes in the receptor binding domain (RBD) of SARS-CoV-2 as determined by biolayer interferometry (BLI). The specificity of antibodies elicited by the qNIV / CoV2373 combination or monovalent CoV2373 was determined by competitive antibody binding of receptor site-specific neutralizing monoclonal antibodies with immune sera by BLI. Horizontal bars indicate group geometric means, error bars indicate 95% confidence intervals. Colored symbols indicate values ​​for individual animals. Antibodies against SARS-CoV-2 US-WA RBD are shown. [Figure 12B] We show that the qNIV / CoV2373 vaccine combination elicits antibodies that bind to highly conserved cryptic epitopes in the receptor binding domain (RBD) of SARS-CoV-2 as determined by biolayer interferometry (BLI). The specificity of antibodies elicited by the qNIV / CoV2373 combination or monovalent CoV2373 was determined by competitive antibody binding of receptor site-specific neutralizing monoclonal antibodies with immune sera by BLI. Horizontal bars indicate group geometric means, error bars indicate 95% confidence intervals. Colored symbols indicate values ​​for individual animals. Antibodies against SARS-CoV-2 US-WA RBD are shown. [Figure 12C]We show that the qNIV / CoV2373 vaccine combination elicits antibodies that bind to highly conserved cryptic epitopes in the receptor binding domain (RBD) of SARS-CoV-2 as determined by biolayer interferometry (BLI). The specificity of antibodies elicited by the qNIV / CoV2373 combination or monovalent CoV2373 was determined by competitive antibody binding of receptor site-specific neutralizing monoclonal antibodies with immune sera by BLI. Horizontal bars indicate group geometric means, error bars indicate 95% confidence intervals. Colored symbols indicate values ​​for individual animals. Antibodies against SARS-CoV-2 US-WA RBD are shown. [Figure 12D] We show that the qNIV / CoV2373 vaccine combination elicits antibodies that bind to highly conserved cryptic epitopes in the receptor binding domain (RBD) of SARS-CoV-2 as determined by biolayer interferometry (BLI). The specificity of antibodies elicited by the qNIV / CoV2373 combination or monovalent CoV2373 was determined by competitive antibody binding of receptor site-specific neutralizing monoclonal antibodies with immune sera by BLI. Horizontal bars indicate group geometric means, error bars indicate 95% confidence intervals. Colored symbols indicate values ​​for individual animals. Antibodies against SARS-CoV-2B.1.351 South Africa RBD are shown. [Figure 12E] We show that the qNIV / CoV2373 vaccine combination elicits antibodies that bind to highly conserved cryptic epitopes in the receptor binding domain (RBD) of SARS-CoV-2 as determined by biolayer interferometry (BLI). The specificity of antibodies elicited by the qNIV / CoV2373 combination or monovalent CoV2373 was determined by competitive antibody binding of receptor site-specific neutralizing monoclonal antibodies with immune sera by BLI. Horizontal bars indicate group geometric means, error bars indicate 95% confidence intervals. Colored symbols indicate values ​​for individual animals. Antibodies against SARS-CoV-2B.1.351 South Africa RBD are shown. [Figure 13A]Weight change and protection against upper and lower respiratory tract infection with SARS-CoV-2 in hamsters immunized with qNIV / CoV2373 combination vaccine. Groups of male and female hamsters (n=5-6 / group) were immunized with a primary / boost regimen of qNIV / CoV2373 or component vaccines, spaced 14 days apart. Three weeks after the second immunization (study day 35), animals were inoculated by intranasal route with 2.0×104 pfu. Weight change (percent change after SARS-CoV-2 inoculation) up to 7 days post infection (dpi) is shown. Data are mean ± SEM for vaccinated, placebo, and sham groups. [Figure 13B] Weight change and protection against upper and lower respiratory tract infection with SARS-CoV-2 in hamsters immunized with qNIV / CoV2373 combination vaccine. Groups of male and female hamsters (n=5-6 / group) were immunized with a primary / boost regimen of qNIV / CoV2373 or component vaccines, spaced 14 days apart. Three weeks after the second immunization (study day 35), animals were inoculated by intranasal route with 2.0×104 pfu. Weight change (percent change after SARS-CoV-2 inoculation) up to 7 days post infection (dpi) is shown. Data are mean ± SEM for vaccinated, placebo, and sham groups. [Figure 13C]Figure 1 shows weight change and protection against upper and lower respiratory tract infection with SARS-CoV-2 in hamsters immunized with qNIV / CoV2373 combination vaccine. Groups of male and female hamsters (n=5-6 / group) were immunized with qNIV / CoV2373 primary / boost regimen or component vaccines, spaced 14 days apart. Three weeks after the second immunization (study day 35), animals were inoculated by intranasal route with 2.0 × 104 pfu. Subgenomic (sg)RNA in buccal mucosa swabs was collected 2, 4, and 7 days post-infection (dpi). sgRNA was analyzed by qRT-PCR. In the box plots, the median is indicated by a horizontal line, the top and bottom of the box indicate the interquartile range, and the whisker faces indicate the minimum and maximum values ​​for each experimental group (n=5-6 / group). Values ​​for individual animals are indicated by colored symbols. Dashed lines indicate the limit of detection (LOD) for the assay. Student's t-test (paired, two-tailed) was used to determine significant differences in viral sgRNA levels between placebo-treated and immunized animals at 2, 4, and 7 dpi. Not significant (ns), ***p≦0.001, ****p≦0.0001. [Figure 13D]Figure 1 shows weight change and protection against upper and lower respiratory tract infection with SARS-CoV-2 in hamsters immunized with qNIV / CoV2373 combination vaccine. Groups of male and female hamsters (n=5-6 / group) were immunized with qNIV / CoV2373 primary / boost regimen or component vaccines, spaced 14 days apart. Three weeks after the second immunization (study day 35), animals were inoculated by intranasal route with 2.0 × 104 pfu. Subgenomic (sg)RNA in buccal mucosa swabs was collected 2, 4, and 7 days post-infection (dpi). sgRNA was analyzed by qRT-PCR. In the box plots, the median is indicated by a horizontal line, the top and bottom of the box indicate the interquartile range, and the whisker faces indicate the minimum and maximum values ​​for each experimental group (n=5-6 / group). Values ​​for individual animals are indicated by colored symbols. Dashed lines indicate the limit of detection (LOD) for the assay. Student's t-test (paired, two-tailed) was used to determine significant differences in viral sgRNA levels between placebo-treated and immunized animals at 2, 4, and 7 dpi. Not significant (ns), ***p≦0.001, ****p≦0.0001. [Figure 13E]Figure 1 shows weight change and protection against upper and lower respiratory tract infection with SARS-CoV-2 in hamsters immunized with qNIV / CoV2373 combination vaccine. Groups of male and female hamsters (n=5-6 / group) were immunized with qNIV / CoV2373 primary / boost regimen or component vaccines, spaced 14 days apart. Three weeks after the second immunization (study day 35), animals were inoculated by intranasal route with 2.0 × 104 pfu. Figure 2 shows sgRNA virus loads in bronchoalveolar lavage fluid collected 7 days post infection (dpi). In the boxplots, the median is indicated by a horizontal line, the top and bottom of the box indicate the interquartile range, and the whisker planes indicate the minimum and maximum values ​​for each experimental group (n=5-6 / group). Values ​​for individual animals are indicated by colored symbols. The dashed line indicates the limit of detection (LOD) for the assay. Student's t-test (paired, two-tailed) was used to determine significant differences in viral sgRNA levels between placebo-treated and immunized animals at 2, 4 and 7 dpi. Not significant (ns), ***p≦0.001, ****p≦0.0001. [Figure 13F] Figure 1 shows weight change and protection against upper and lower respiratory tract infection with SARS-CoV-2 in hamsters immunized with qNIV / CoV2373 combination vaccine. Groups of male and female hamsters (n=5-6 / group) were immunized with qNIV / CoV2373 primary / boost regimen or component vaccines, spaced 14 days apart. Three weeks after the second immunization (study day 35), animals were inoculated by intranasal route with 2.0 × 104 pfu. sgRNA viral load in lung homogenates collected at 7 dpi is shown. In the boxplots, the median is indicated by the horizontal line, the top and bottom of the box indicate the interquartile range, and the whisker planes indicate the minimum and maximum values ​​for each experimental group (n=5-6 / group). Values ​​for individual animals are indicated by colored symbols. The dashed line indicates the limit of detection (LOD) for the assay. Student's t-test (paired, two-tailed) was used to determine significant differences in viral sgRNA levels between placebo-treated and immunized animals at 2, 4 and 7 dpi. Not significant (ns), ***p≦0.001, ****p≦0.0001. [Figure 13G] Figure 1 shows weight change and protection against upper and lower respiratory tract infection with SARS-CoV-2 in hamsters immunized with qNIV / CoV2373 combination vaccine. Groups of male and female hamsters (n=5-6 / group) were immunized with qNIV / CoV2373 primary / boost regimen or component vaccines, spaced 14 days apart. Three weeks after the second immunization (study day 35), animals were inoculated by intranasal route with 2.0 × 104 pfu. Lung weights collected at 7 dpi from vaccinated, placebo-treated, and untreated sham animals are shown. Bars indicate the mean and error bars ± standard deviation (SD). Values ​​for individual animals are indicated by colored symbols. Student's t-test (paired, two-tailed) was used to determine significant differences in lung weights between the indicated paired groups. [Figure 14]Figure 1 shows histopathological changes in the lungs of hamsters immunized with the qNIV / CoV2373 combination vaccine and challenged with SARS-CoV-2. Groups of male and female hamsters were immunized with the qNIV / CoV2373 combination with 2.5 or 10 μg hemagglutinin (HA) per strain combined with 1 or 5 μg CoV2373 adjuvanted with saponin adjuvant. Comparators were immunized with 2.5 or 10 μg HA / strain or 1 or 5 μg CoV2373 recombinant spike adjuvanted with 15 μg saponin adjuvant. All groups were immunized with two doses, 14 days apart. The placebo group received the formulation buffer. Three weeks after the second immunization (study day 35), all animals were inoculated intranasally with 2.0 × 104 pfu of SARS-CoV-2 and lungs were harvested 7 dpi. Histological images were stained with hematoxylin and eosin (H&E). A is a sham control image showing normal lungs. B shows microscopic findings in the lungs of animals treated with placebo, showing airway involvement by bronchoalveolar hyperplasia (arrows) with mixed alveolar inflammation. Mononuclear inflammatory cells surround blood vessels (arrowheads) with edema that expands the surrounding tissue (arrowheads). C-D shows microscopic findings in the lungs of animals immunized with qNIV, showing similar histological changes to the placebo group, including mixed alveolitis with perivascular inflammation and extensive bronchoalveolar hyperplasia (arrows) with dilated vessel walls (arrows). E-F shows images of lungs from animals immunized with monovalent CoV2373 showing no significant microscopic findings. 14G-J are images of the lungs of animals immunized with the qNIV / CoV2373 combination vaccine, showing no significant microscopic findings, magnification 10x. [Figure 15] 1 shows the titers of anti-spike IgG antibodies as a function of the dose of hemagglutinin and CoV S polypeptides from day 0 to day 28 after immunization according to Example 5. [Figure 16] 1 shows HAI geometric mean titers against A / Brisbane H1N1 as a function of hemagglutinin and CoV S polypeptide dose from day 0 to day 28 post immunization according to Example 5. [Figure 17]1 shows HAI geometric mean titers against A / Kansas H3N2 as a function of hemagglutinin and CoV S polypeptide dose from day 0 to day 28 post-immunization according to Example 5. [Figure 18] 1 shows HAI geometric mean titers against B / Maryland (Vic) as a function of hemagglutinin and CoV S polypeptide dose from day 0 to day 28 post immunization according to Example 5. [Figure 19] 1 shows HAI geometric mean titers against B / Phuket (Yam) as a function of hemagglutinin and CoV S polypeptide dose from day 0 to day 28 post-immunization according to Example 5. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] definition As used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the content clearly dictates otherwise. Thus, for example, reference to "a protein" can refer to one protein or a mixture of such proteins, and reference to "the method" includes references to equivalent steps and / or methods known to those skilled in the art, and so forth.

[0011] As used herein, the term "adjuvant" refers to a compound that, when used in combination with an immunogen, enhances or otherwise alters or modifies the immune response elicited against the immunogen. Modification of the immune response can include enhancing or broadening the specificity of either or both the antibody and cellular immune responses.

[0012] As used herein, the term "about" or "approximately" when preceding a numerical value indicates the value plus or minus a range of 10%. For example, "about 100" includes 90 and 110.

[0013] As used herein, the terms "immunogen," "antigen," and "epitope" refer to substances such as proteins, including glycoproteins, and peptides that are capable of eliciting an immune response.

[0014] As used herein, an "immunogenic composition" is a composition that includes an antigen, the administration of which to a subject results in the development in the subject of a humoral and / or cellular immune response to the antigen.

[0015] As used herein, a "subunit" composition, e.g., a vaccine, comprises one or more selected antigens, but does not comprise all antigens from a pathogen. Such compositions are substantially free of intact viruses or lysates of such cells or particles, and are typically prepared from immunogenic polypeptides that have been at least partially purified, and often substantially purified, from a pathogen. The antigens in the subunit compositions disclosed herein are typically prepared recombinantly, often using a baculovirus system.

[0016] As used herein, "substantially" refers to the isolation of a substance (e.g., a compound, polynucleotide, or polypeptide) in which the substance constitutes a majority of the sample in which it is contained. For example, in a sample, a substantially purified component constitutes 85% of the sample, preferably 85%-90%, more preferably at least 95%-99.5%, and most preferably at least 99%. When a component has been substantially replaced, the amount remaining in the sample is about 0.5% to about 10% or less, preferably about 0.5% to about 1.0% or less.

[0017] As used herein, the terms "treat," "treatment," or "treating" refer to an approach for obtaining beneficial or desired results, e.g., clinical results. For purposes of this disclosure, beneficial or desired results may include inhibiting or suppressing the onset or progression of an infection or disease, ameliorating symptoms or reducing the manifestation of an infection or disease, or a combination thereof.

[0018] As used herein, "Prevention" is used interchangeably with "prophylaxis" and can mean preventing an infection or disease altogether, or preventing the onset of symptoms of that infection or disease, delaying the onset of an infection or disease or symptom thereof, or reducing the severity of a subsequently occurring infection or disease or symptom thereof.

[0019] As used herein, "effective dose" or "effective amount" refers to an amount of an immunogen sufficient to elicit an immune response that alleviates at least one symptom of a pathogen infection. An effective dose or amount can be measured, for example, by the amount of neutralizing secretory and / or serum antibodies, e.g., by plaque neutralization, complement fixation, enzyme-linked immunosorbent (ELISA), or microneutralization assays.

[0020] As used herein, the term "vaccine" refers to an immunogenic composition, such as an immunogen derived from a pathogen, used to induce an immune response against the pathogen. The immune response may include the formation of antibodies and / or a cell-mediated response. Depending on the context, the term "vaccine" may also refer to a suspension or solution of an immunogen administered to a subject to generate an immune response. Preferably, the vaccine induces an immune response effective to prevent infection from SARS-CoV-2, its SARS-CoV-2 variants, influenza, or a combination thereof.

[0021] As used herein, the term "patient" or "subject" includes humans and other animals. Typically, the subject is a human. For example, the subject may be an adult, a teenager, a child (2-14 years old), an infant (birth to 2 years old), or a newborn (up to 2 months old). In certain embodiments, the subject is up to 4 months old, or up to 6 months old. In embodiments, the adult is about 65 years old or older, or about 60 years old or older. In embodiments, the subject is a pregnant woman, or a woman who intends to become pregnant. In other embodiments, the subject is not a human, e.g., a non-human primate, e.g., a baboon, chimpanzee, gorilla, or macaque. In certain embodiments, the subject may be a pet, such as a dog or a cat.

[0022] In an embodiment, the subject is immunocompromised. In an embodiment, the immunocompromised subject is administered a drug that causes immunosuppression. Non-limiting examples of drugs that cause immunosuppression include corticosteroids (e.g., prednisone), alkylating agents (e.g., cyclophosphamide), antimetabolites (e.g., azathioprine or 6-mercaptopurine), transplant-related immunosuppressants (e.g., cyclosporine, tacrolimus, sirolimus, or mycophenolate mofetil), mitoxantrone, chemotherapy agents, methotrexate, tumor necrosis factor (TNF) blocking agents (e.g., etanercept, adalimumab, infliximab). In an embodiment, the immunocompromised subject is infected with a virus (e.g., human immunodeficiency virus or Epstein-Barr virus). In an embodiment, the virus is a respiratory virus, such as respiratory syncytial virus, influenza, parainfluenza, adenovirus, or picornavirus. In embodiments, the immunocompromised subject has acquired immune deficiency syndrome (AIDS). In embodiments, the immunocompromised subject is a human surviving with human immunodeficiency virus (HIV). In embodiments, the immunocompromised subject is made immunocompromised by a therapeutic regimen designed to prevent inflammation or prevent rejection of the graft. In embodiments, the immunocompromised subject is a subject who has received a graft. In embodiments, the immunocompromised subject has undergone radiation therapy or splenectomy.In embodiments, the immunocompromised subject may have a medical condition that is associated with cancer, an autoimmune disease, tuberculosis, a substance use disorder (e.g., alcohol, opioid, or cocaine use disorder), stroke or cerebrovascular disease, solid organ or blood stem cell transplant, sickle cell disease, thalassemia, autoimmune lymphoproliferative syndrome (ALPS), autoimmune polyglandular syndrome type 1 (APS-1), B-cell expansion with NF-κB and T-cell anergy disorder (BENTA), caspase-8 deficiency state (CEDS), chronic granulomatous disease (CGD), common variable immunodeficiency (CVID), congenital neutropenia, cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) deficiency, DOCK8 deficiency, GATA2 deficiency, glycosylation disorder with immunodeficiency, hyperimmunoglobulin E syndrome (HIES), The subject has been diagnosed with Hyperimmunoglobulin M syndrome, diabetes, type 1 diabetes, type 2 diabetes, interferon gamma deficiency, interleukin 12 deficiency, interleukin 23 deficiency, leukocyte adhesion deficiency, lipopolysaccharide-responsive beige-like anchor (LRBA) deficiency, PI3 kinase disease, PLCG2-associated antibody deficiency and immune dysregulation (PLAID), severe combined immunodeficiency (SCID), STAT3 dominant negative disease, STAT3 gain of function disease, warts, hypogammaglobulinemia, infection, and myeloid cell pool (WHIM) syndrome, Wiskott-Aldrich syndrome (WAS), X-linked agammaglobulinemia (XLA), X-linked lymphoproliferative disease (XLP), uremia, malnutrition, or an XMEN disease. In an embodiment, the immunocompromised subject is a current or former tobacco smoker. In embodiments, the immunocompromised subject has a B cell deficiency, a T cell deficiency, a macrophage deficiency, a cytokine deficiency, a phagocyte deficiency, a phagocyte dysfunction, a complement deficiency, or a combination thereof.

[0023] In some embodiments, the subject is overweight or obese. In embodiments, an overweight subject is below 25 kg / m 2 More than 30kg / m 2 In embodiments, an obese subject has a body mass index (BMI) of less than 30 kg / m 2In embodiments, the subject has a BMI that is greater than or equal to 1. In embodiments, the subject has a mental health condition. In embodiments, the mental health condition is depression, schizophrenia, or anxiety.

[0024] As used herein, the term "pharmaceutical acceptable" means approved by a regulatory agency of the U.S. Federal or state government, or listed in the United States Pharmacopoeia, the European Pharmacopoeia, or other generally recognized pharmacopoeias, for use in mammals, especially humans. These compositions may be useful as vaccine and / or antigen compositions for inducing a protective immune response in vertebrates.

[0025] As used herein, the term "about" means ±10% of the indicated numerical value.

[0026] As used herein, the term "NVX-CoV2373" refers to a vaccine composition comprising the BV2373 spike glycoprotein (SEQ ID NO:87) and an ISCOM matrix of Fraction A and Fraction C (e.g., Matrix-M™).

[0027] As used herein, "Quad-NIV," "QuadNIV," or "quadrivalent nanoparticle influenza vaccine," or "qNIV" refers to an influenza vaccine formulation that contains antigens from four influenza virus strains.

[0028] As used herein, the term "modification" when referring to a CoV S polypeptide refers to a mutation, deletion, or addition of one or more amino acids of the CoV S polypeptide. The location of the modification within the CoV S polypeptide can be determined by aligning the sequence of the polypeptide to SEQ ID NO:1 (CoV S polypeptide including the signal peptide) or SEQ ID NO:2 (mature CoV S polypeptide without the signal peptide).

[0029] The term variant of SARS-CoV-2, which may be used interchangeably with "heterogeneous SARS-CoV-2 strain," refers to a variant of SARS-CoV-2 that has at least about 2, at least about 3, at least about 4, at least about 5, at least about 6, at least about 7, at least about 8, at least about 9, at least about 10, at least about 11, at least about 12, at least about 13, at least about 14, at least about 15, at least about 16, at least about 17, at least about 18, at least about 19, at least about 20, at least about 21, at least about 22, at least about 23, at least about 24, at least about 25, at least about 26, at least about 27, at least about 28, at least about 29, at least about 30, at least about 31, at least about 32, at least about 33, at least about 34, at least about 35, at least about 36, at least about 37, at least about 38, at least about 39, at least about 40, at least about 41, at least about 42, at least about 43, at least about 44, at least about 45, at least about 46, at least about 47, at least about 48, at least about 49, at least about 50, at least about 51, at least about 52, at least about 53, at least about 54, at least about 55, at least about 56, at least about 57, at least about 58, at least about 59, at least about 60, at least about 61, at least about 62, at least about 63, at least about 64, at least about 65, at least about 66, at least about 67, at least about 68, at least at least about 24, at least about 25, at least about 26, at least about 27, at least about 28, at least about 29, at least about 30, at least about 31, at least about 32, at least about 33, at least about 34, or at least about 35 modifications, about 2 to about 35 modifications, about 5 to about 10 modifications, about 5 to about 20 modifications, about 10 to about 20 modifications, about 15 to about 25 modifications, about 20 to 30 modifications, about 20 to about 40 modifications, or about 25 to 45 modifications. In embodiments, the heterogeneous SARS-CoV-2 strain is a SARS-CoV-2 virus comprising a CoV S polypeptide having at least about 70%, at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, or at least about 99% identity to a CoV S polypeptide having the amino acid sequence of SEQ ID NO:1 or SEQ ID NO:2. In embodiments, the heterogeneous SARS-CoV-2 strain is a SARS-CoV-2 virus comprising a CoV S polypeptide having about 70% to about 99.9% identity to a CoV S polypeptide having the amino acid sequence of SEQ ID NO:1 or SEQ ID NO:2. In embodiments, the heterogeneous SARS-CoV-2 strain is a SARS-CoV-2 virus comprising a CoV S polypeptide having about 70% to about 99.5% identity to a CoV S polypeptide having the amino acid sequence of SEQ ID NO:1 or SEQ ID NO:2.In embodiments, the heterogeneous SARS-CoV-2 strain is a SARS-CoV-2 virus comprising a CoV S polypeptide having about 90% to about 99.9% identity to a CoV S polypeptide having the amino acid sequence of SEQ ID NO:1 or SEQ ID NO:2. In embodiments, the heterogeneous SARS-CoV-2 strain is a SARS-CoV-2 virus comprising a CoV S polypeptide having about 90% to about 99.8% identity to a CoV S polypeptide having the amino acid sequence of SEQ ID NO:1 or SEQ ID NO:2. In embodiments, the heterogeneous SARS-CoV-2 strain is a SARS-CoV-2 virus comprising a CoV S polypeptide having about 95% to about 99.9% identity to a CoV S polypeptide having the amino acid sequence of SEQ ID NO:1 or SEQ ID NO:2. In embodiments, the heterogeneous SARS-CoV-2 strain is a SARS-CoV-2 virus comprising a CoV S polypeptide having about 95% to about 99.8% identity to a CoV S polypeptide having the amino acid sequence of SEQ ID NO:1 or SEQ ID NO:2. In embodiments, the heterogeneous SARS-CoV-2 strain is a SARS-CoV-2 virus comprising a CoV S polypeptide having about 95% to about 99% identity to a CoV S polypeptide having the amino acid sequence of SEQ ID NO:1 or SEQ ID NO:2.

[0030] The term "B.1.1.7 SARS-CoV-2 strain" (also referred to as an "alpha" strain) refers to a heterogeneous SARS-CoV-2 strain having a CoV S polypeptide containing a deletion of amino acids 69, 70, and 144, and the following mutations: N501Y, A570D, D614G, P681H, or P681R, T716I, S982A, and D1118H, where the CoV S polypeptide is numbered relative to the wild-type SARS-CoV-2 S polypeptide having the amino acid sequence of SEQ ID NO: 1. The CoV S polypeptide of the B.1.1.7 SARS-CoV-2 strain may optionally contain a deletion of amino acid 145, the following mutations: E484K, L432R, or S494P, or a combination thereof.

[0031] The term "B.1.351 SARS-CoV-2 strain" (also referred to as a "beta" strain) refers to a heterogeneous SARS-CoV-2 strain having a CoV S polypeptide that includes the following mutations: D80A, K417N, E484K, N501Y, D614G, and A701V, where the CoV S polypeptide is numbered relative to the wild-type SARS-CoV-2 S polypeptide having the amino acid sequence of SEQ ID NO: 1. The CoV S polypeptide of the B.1.617.2 SARS-CoV-2 strain may optionally include one or more of the following mutations: D215G; L242H; R246I; or a deletion of one, two, or three amino acids among 241-243, where the CoV S polypeptide is numbered relative to the wild-type SARS-CoV-2 S polypeptide having the amino acid sequence of SEQ ID NO: 1. In embodiments, the CoV S polypeptide of the beta strain comprises the mutations D80A, D215G, L242H, K417N, E484K, N501Y, D614G, and A701V, where the CoV S polypeptide is numbered relative to the wild-type SARS-CoV-2 S polypeptide having the amino acid sequence of SEQ ID NO: 1. In embodiments, the CoV S polypeptide of the beta strain comprises the mutations D80A, D215G, deletion of one, two, or three amino acids among amino acids 241-243, K417N, E484K, N501Y, D614G, and A701V, where the CoV S polypeptide is numbered relative to the wild-type SARS-CoV-2 S polypeptide having the amino acid sequence of SEQ ID NO: 1. In embodiments, the Beta strain comprises the mutations D80A, L242H, R246I, N501Y, K417N, E484K, D614G, and A701V, where the CoV S polypeptide is numbered relative to the wild-type SARS-CoV-2 S polypeptide having the amino acid sequence of SEQ ID NO:1.

[0032] The term "P.1 SARS-CoV-2 strain" (also referred to as the "gamma" strain) refers to a heterogeneous SARS-CoV-2 strain having a CoV S polypeptide containing the mutations L18F, T20N, P26S, D138Y, R190S, K417T, E484K, N501Y, D614G, H655Y, T1027I, and V1176F, where the CoV S polypeptide is numbered relative to the wild-type SARS-CoV-2 S polypeptide having the amino acid sequence of SEQ ID NO:1.

[0033] The term "Cal.20C SARS-CoV-2 strain" refers to a heterogeneous SARS-CoV-2 strain having a CoV S polypeptide containing the mutations S13I, W152C, and L452R, where the CoV S polypeptide is numbered relative to the wild-type SARS-CoV-2 S polypeptide having the amino acid sequence of SEQ ID NO:1.

[0034] The term "B.1.617.2 strain" (also referred to as the "delta" strain) refers to a heterogeneous SARS CoV-2 strain having a CoV S polypeptide containing a deletion of amino acids 157 and 158, and the following mutations: T19R, E156G, L452R, T478K, D614G, P681R, and D950N, where the CoV S polypeptide is numbered relative to the wild-type SARS-CoV-2 S polypeptide having the amino acid sequence of SEQ ID NO:1. A CoV S polypeptide of a B.1.617.2 SARS-CoV-2 strain may optionally include one or more of the following mutations: G142D, W64H, H66W, V70F, T95I, Y145H, D213V, L214R, A222V, W258I or W258L; K417N; N439K; E484K or E484Q; N501Y; and Q613H, where the CoV S polypeptide is numbered relative to a wild-type SARS-CoV-2 S polypeptide having the amino acid sequence of SEQ ID NO: 1. In embodiments, a delta strain comprises a CoV S polypeptide that includes a deletion of amino acids 157 and 158, and the following mutations: T19R, G142D, E156G, L452R, T478K, D614G, P681R, and D950N. In embodiments, the Delta strain comprises a CoV S polypeptide comprising a deletion of amino acids 157 and 158, and the following mutations: T19R, T95I, G142D, Y145H, E156G, A222V, K417N, L452R, T478K, D614G, P681R, and D950N, where the CoV S polypeptide is numbered relative to the wild-type SARS-CoV-2 S polypeptide having the amino acid sequence of SEQ ID NO:1. In embodiments, the Delta strain comprises a CoV S polypeptide comprising a deletion of amino acids 157 and 158, and the following mutations: T19R, G142D, E156G, W258I, K417N, N439K, L452R, T478K, E484K, N501Y, D614G, P681R, and D950N, where the CoV S polypeptide is numbered relative to a wild-type SARS-CoV-2 S polypeptide having the amino acid sequence of SEQ ID NO:1.In embodiments, the Delta strain comprises a CoV S polypeptide comprising a deletion of amino acids 157 and 158, and the following mutations: T19R, W64H, H66W, G142D, E156G, D213V, L214R, W258I, K417N, N439K, L452R, T478K, E484K, N501Y, D614G, P681R, and D950N, where the CoV S polypeptide is numbered relative to a wild-type SARS-CoV-2 S polypeptide having the amino acid sequence of SEQ ID NO:1. In embodiments, the Delta strain comprises a CoV S polypeptide comprising a deletion of amino acids 157 and 158, and the following mutations: T19R, G142D, E156G, K417N, L452R, T478K, E484Q, D614G, P681R, and D950N, where the CoV S polypeptide is numbered relative to a wild-type SARS-CoV-2 S polypeptide having the amino acid sequence of SEQ ID NO:1.

[0035] The term "strain B.1.525" (also referred to as the "Eta" strain) refers to a heterogeneous SARS-CoV-2 strain having a CoV S polypeptide containing the mutations Q52R; A67V; E484K; D614G; Q677H; F888L; and a deletion of 1, 2, 3 or 4 of amino acids 69, 70, 144, 145, where the CoV S polypeptide is numbered relative to the wild-type SARS-CoV-2 S polypeptide having the amino acid sequence of SEQ ID NO:1.

[0036] The term "strain B.1.526" (also known as the "iota" strain) refers to a heterogeneous SARS-CoV-2 strain having a CoV S polypeptide containing the mutations L5F; T95I; D253G; E484K; D614G; and A701V, where the CoV S polypeptide is numbered relative to the wild-type SARS-CoV-2 S polypeptide having the amino acid sequence of SEQ ID NO:1.

[0037] The term "B.1.617.1 strain" (also referred to as the "kappa" strain) refers to a heterogeneous SARS-CoV-2 strain having a CoV S polypeptide containing the mutations L452R; E484Q; D614G; P681R; and Q1071H, where the CoV S polypeptide is numbered relative to the wild-type SARS-CoV-2 S polypeptide having the amino acid sequence of SEQ ID NO:1.

[0038] The term "C.37 strain" (also known as the "lambda" strain) refers to a heterogeneous SARS-CoV-2 strain having a CoV S polypeptide containing the mutations G75V; T76I; R246N; L452Q; F490S; D614G; T859N; and a deletion of 1, 2, 3, 4, 5, or 6 of amino acids 247-253, where the CoV S polypeptide is numbered relative to the wild-type SARS-CoV-2 S polypeptide having the amino acid sequence of SEQ ID NO:1.

[0039] The term "strain B.1.621" (also referred to as the "mu" strain) refers to a heterogeneous SARS-CoV-2 strain having a CoV S polypeptide containing the mutations T95I; Y144S; Y145N; R346K; E484K; N501Y; D614G; P681H; and D950N, where the CoV S polypeptide is numbered relative to the wild-type SARS-CoV-2 S polypeptide having the amino acid sequence of SEQ ID NO:1.

[0040] The term "B.1.1.529 strain", used interchangeably with "Omicron" variant, refers to a heterogeneous SARS-CoV-2 strain having a CoV S polypeptide including the mutations G142D; G339D; S373P; S375F; K417N; N440K; T478K; E484A or E484K; Q493K or Q493R; Q498R; N501Y; Y505H; D614G; H655Y; N679K; P681H; N764K; D796Y; Q954H and N969K, where the CoV S polypeptide is numbered relative to the wild-type SARS-CoV-2 S polypeptide having the amino acid sequence of SEQ ID NO:1. A CoV S polypeptide of the B.1.1.529 SARS-CoV-2 strain optionally includes one or more of the following mutations: T19I, L24S, A67V, T95I, N211I, L212I or L212V, V213P or V213G; R214E; S371L; T376A; D405N; R408S; G446S; S477N; G496S; T547K; N856K; L981F; G496S; an insertion of the amino acid PPA after amino acid 25; an insertion of the amino acid EPE after amino acid 214 or 215; or a deletion of one or more of amino acids 25, 26, 27, 69, 70, 143, 144, 145, 211, 212, where CoV The S polypeptides are numbered relative to the wild-type SARS-CoV-2 S polypeptide having the amino acid sequence of SEQ ID NO: 1. Optionally, the SARS-CoV-2 S omicron variant is the SARS-CoV-2 S omicron BA.1 variant.This strain is SARS-CoV-2 The S polypeptide comprises the following mutations: A67V; deletion of amino acids 69-70; T95I; G142D; deletion of amino acids 143-145; N211I; deletion of amino acid 212 and insertion of amino acid EPE after amino acid 214; G339D; S371L; S373P; S375F; K417N; N440K; G446S; S477N; T478K; E484A; Q493R; G496S; Q498R; N501Y; Y505H; T547K; D614G; H655Y; N679K; P681H; N764K; D796Y; N856K; Q954H; N969K; and L981F, where the polypeptide is numbered with respect to SEQ ID NO:1. Optionally, the SARS-CoV-2 S omicron variant is a SARS-CoV-2 S omicron BA.2 variant, which comprises the following mutations in the SARS-CoV-2 S polypeptide: T19I; L24S; a deletion at amino acids 25-27; G142D; V213G; G339D; S371F; S373P; S375F; T376A; D405N; R408S; K417N; N440K; S477N; T478K; E484A; Q493R; Q498R; N501Y; Y505H; D614G; H655Y; N679K; P681H; N764K; D796Y; Q954H; and N969K, where the polypeptide is numbered relative to SEQ ID NO:1.

[0041] A subject who is "positive" for SARS-CoV-2 or its variants has a positive PCR test or serology test for SARS-CoV-2 or its variants. A positive PCR test detects genetic material from SARS-CoV-2 or its variants. A positive serology test indicates the presence of antibodies to a SARS-CoV-2 protein, typically the nucleocapsid protein from SARS-CoV-2 or its variants.

[0042] The term "asymptomatic" refers to subjects who test positive for SARS-CoV-2 or its SARS-CoV-2 variants but do not experience any symptoms of COVID-19.

[0043] The term "mild" with respect to COVID-19 refers to a subject who has a positive PCR or serology test for SARS-CoV-2 or a variant thereof and has one or more of the following symptoms: (i) fever; (ii) new-onset cough; (iii) or new-onset or worsening shortness of breath or difficulty breathing, fatigue, generalized muscle or body aches, headache, loss of taste or smell; sore throat, stuffy nose, runny nose; or nausea, vomiting, diarrhea.

[0044] The term "moderate" with respect to COVID-19 refers to a subject with a positive PCR or serology test for SARS-CoV-2 or a variant thereof and one or more of the following symptoms: (i) high fever of 38.4°C or greater for 3 days or more, (ii) evidence of significant lower respiratory tract infection (LRTI), where the evidence is selected from: (a) shortness of breath with or without exertion; (b) tachypnea (24-29 breaths per minute at rest); (c) SpO2 of 94%-95%; (d) chest x-ray or computed tomography (CT) abnormalities consistent with pneumonia or LRTI, or (e) adventitious sounds on lung auscultation (e.g., crackles / rales, wheezing, pleural rub, stridor).

[0045] The term "severe" with respect to COVID-19 is defined as having a positive PCR or serology test for SARS-CoV-2 or a variant thereof and the following symptoms: (i) tachypnea of ​​30 breaths or more per minute at rest; (ii) resting heart rate of 125 beats per minute or more; (iii) SpO2 of 93% or less or PaO2 / FiO2 of less than 300 mmHg; (iv) requirement for high-flow oxygen therapy or noninvasive ventilation, noninvasive positive pressure ventilation (e.g., continuous positive airway pressure (CPAP) or bilevel positive airway pressure (BiPAP)); (v) requirement for mechanical ventilation or extracorporeal membrane oxygenation (ECMO); (vi) requirement for (a) acute respiratory distress syndrome (ARDS); (b) acute kidney injury (KIBI); (c) acute liver failure; (d) acute right or left heart failure; (e) septic or cardiogenic shock (with shock defined as systolic blood pressure (SBP) less than 90 mmHg or diastolic blood pressure (DBP) less than 60 mmHg); (f) acute stroke (ischemic or hemorrhagic); (g) acute thrombotic event such as acute myocardial infarction (AMI), deep vein thrombosis (DVT), pulmonary embolism (PE); (h) dysfunction or failure of one or more major organ systems selected from requirement for vasopressors, systemic corticosteroids, or hemodialysis; (vii) admission to an intensive care unit; or (viii) death.

[0046] As used herein, the terms "bedside mix", "bedside formulation", "bedside vaccine composition", "bedside vial", and "bedside vial formulation" refer to a vaccine formulation that is prepared immediately prior to administration. Such a vaccine formulation comprises a viral antigen and an adjuvant that are stored separately in different containers and administered to a subject (e.g., administering two sequential injections or combining antigen and adjuvant in a single injection prior to administration).

[0047] As used herein, the terms "co-formulated mixture," "co-formulation," "co-formulated vaccine composition," "pre-filled syringe," and "premix" refer to a vaccine formulation that is prepared for short- to long-term storage prior to administration to a subject. Such vaccine formulations contain a combination of antigen and adjuvant in the same container and are prepared prior to administration. In embodiments, the formulation includes hemagglutinin and an adjuvant (e.g., a saponin adjuvant) that form HaSMaN (hemagglutinin saponin matrix nanoparticles).

[0048] The term "efficacy" of the immunogenic or vaccine compositions described herein refers to the percentage reduction in disease (e.g., COVID-19) in a group administered the immunogenic composition compared to a group not administered the immunogenic composition. In embodiments, efficacy (E) is calculated using the following equation: E(%)=(1-RR)×100, where RR=relative risk of disease incidence between a group administered the immunogenic composition and a group not administered the immunogenic composition. In embodiments, the immunogenic compositions described herein have an efficacy of at least about 50%, at least about 55%, at least about 60%, at least about 65%, at least about 70%, at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 91%, at least about 92%, at least about 93%, at least about 94%, at least about 95%, at least about 96%, at least about 98%, at least about 99%, at least about 100%, at least about 101%, at least about 102%, at least about 103%, at least about 104%, at least about 105%, at least about 106%, at least about 107%, at least about 108%, at least about 109%, at least about 110%, at least about 111%, at least about 112%, at least about 113%, at least about 114%, at least about 115%, at least about 116%, at least about 117%, at least about 118%, at least about 119%, at least about 120%, at least about 121%, at least about 122%, at least about 123%, at least about 124%, at least about 125%, at least about 126%, at least about 127%, at least about 128%, at least about 129%, at least about 130%, at least about 131%, at least about 132%, at least about 13 or about 96%, at least about 97%, at least about 98%, at least about 99%, about 50% to about 99%, about 50% to about 98%, about 60% to about 99%, about 60% to about 98%, about 70% to about 98%, about 70% to about 95%, about 70% to about 99%, about 80% to about 99%, about 80% to about 98%, about 80% to about 95%, about 85% to about 99%, about 85% to about 98%, about 85% to about 95%, about 90% to about 95%, about 90% to 98%, or about 90% to about 99% efficacy.

[0049] As used herein, the term "split virion" refers to a virus (e.g., influenza virus or SARS-CoV-2 virus) that has a viral membrane that has been disrupted with detergent. Examples of detergents are described throughout this disclosure. Because split virions have not undergone further purification, they typically contain multiple viral proteins.

[0050] As used herein, the term "recombinant" refers to a protein (e.g., hemagglutinin) produced within a cell by transcription and translation of a nucleic acid that is introduced into the cell. The nucleic acid may be introduced via a vector or a virus that encodes the nucleic acid.

[0051] As used herein, the term "whole influenza virus" refers to a virus including all of its envelope, viral membranes, nucleocapsid, and genetic material. In embodiments, the whole influenza virus is inactivated.

[0052] As used herein, the term "inactivated virus" refers to a virus that has undergone a process to substantially reduce or eliminate its pathogenicity compared to the wild-type virus. Immunogenic compositions against coronaviruses and influenza viruses

[0053] Provided herein are immunogenic and vaccine compositions comprising: (i) at least three hemagglutinin (HA) glycoproteins, where the three hemagglutinin (HA) glycoproteins are from different influenza strains; (ii) a CoV S polypeptide in the form of a detergent-core nanoparticle, where the detergent is a non-ionic detergent; and (iii) a pharma- ceutically acceptable buffer. In embodiments, the at least three HA glycoproteins are in a form selected from the group consisting of: (a) detergent-core nanoparticles comprising hemagglutinin (HA), (b) HaSMaN (hemagglutinin saponin matrix nanoparticles), (c) inactivated whole influenza virus, (d) a hemagglutinin composition extracted from influenza virus, an optional influenza split virion composition or a subunit influenza composition, and any combination thereof. Provided herein in embodiments are methods of using the aforementioned immunogenic and vaccine compositions to stimulate an immune response against coronavirus, influenza virus, or a combination thereof.

[0054] Also provided herein are methods of producing said nanoparticles and immunogenic compositions. Advantageously, the methods provide nanoparticles that are substantially free of contamination with other proteins, such as proteins associated with recombinant expression of proteins in insect cells. In embodiments, expression occurs in the baculovirus / Sf9 system.

[0055] (i) a non-naturally occurring CoV S polypeptide or nanoparticle; The immunogenic compositions of the present disclosure include a non-naturally occurring CoV S polypeptide or nanoparticles comprising the same. The CoV S polypeptide can be derived from a coronavirus, including, but not limited to, SARS-CoV-2, e.g., SARS-CoV-2, MERS CoV, and SARS CoV.

[0056] In embodiments, the variant of SARS-CoV-2 is SARS-CoV-2 VUI 202012 / 01, B.1.1.7 (also referred to as "501Y.V1" and "alpha"), B.1.351 (also referred to as "501Y.V2" and "beta"), B.1.617.2 (also referred to as "delta"), Cal.20C (also referred to as "epsilon"), or P.1 (also referred to as "gamma"). Variants of SARS-CoV-2 are designated by their World Health Organization (WHO) designation (e.g., alpha, beta, gamma, delta, etc.), by their Phylogenetic Assignment of Named Global Outbreak (PANGO) lineage, by their GISAID clade, or by their Nextstrain clade.

[0057] [Table 1-1] [Table 1-2] [Table 1-3] [Table 1-4]

[0058] In embodiments, the SARS-CoV-2 virus has a CoV S polypeptide having the amino acid sequence of SEQ ID NO:1, and the variant of SARS-CoV-2 has at least about 1, at least about 2, at least about 3, at least about 4, at least about 5, at least about 6, at least about 7, at least about 8, at least about 9, at least about 10, at least about 11, at least about 12, at least about 13, at least about 14, at least about 15, at least about 16, at least about 17, at least about 18, at least about 19, at least about 20, at least about 21, at least about 22, at least about 23, at least about 24, at least about 25, at least about 26, at least about 27, at least about 28, at least about 29, at least about 30, at least about 31, at least about 32, at least about 33, at least about 34, at least about 35, at least about 36, at least about 37, at least about 38, at least about 39, at least about 40, at least about 41, at least about 42, at least about 43, at least about 44, at least about 45, at least about 46, at least about 47, at least about 48, at least about 49, at least about 50, at least about 51, at least about 52, at least about 53, at least about 54, at least about 55, at least about 56, at least about 57, at least about 58, at least about 59, at least about 60, at least about 61, at least about 62, at least about 63, at least about 64, at least about 65, at least about 66, at least about 67, at least about 68, at least about 69, or at least about 70 modifications.

[0059] In contrast to the SARS-CoV-S protein, the SARS-CoV-2 S protein has a four amino acid insertion at the S1 / S2 cleavage site resulting in a polybasic RRAR furin-like cleavage motif. The SARS-CoV-2 S protein is synthesized as an inactive precursor (S0) that is proteolytically cleaved at the furin cleavage site into S1 and S2 subunits that remain non-covalently associated to form the prefusion trimer. The S2 domain of the SARS-CoV-2 S protein contains a fusion peptide (FP), two heptad repeats (HR1 and HR2), a transmembrane (TM) domain, and a cytoplasmic tail (CT). The S1 domain of the SARS-CoV-2 S protein folds into four distinct domains, namely the N-terminal domain (NTD) and the C-terminal domain, which contain the receptor binding domain (RBD) and two subdomains SD1 and SD2. The pre-fusion SARS-CoV-2 S protein trimer undergoes a structural transition from a pre-fusion to a post-fusion conformation upon S-protein receptor binding and cleavage.

[0060] In embodiments, the CoV S polypeptide is a glycoprotein due to post-translational glycosylation. The glycoprotein comprises one or more of a signal peptide, an S1 subunit, an S2 subunit, an NTD, a, an RBD, two subdomains (SD1 and SD2, labeled SD1 / 2 in Figures 6A-6B and referred to herein as "SD1 / 2"), an intact or modified fusion peptide, an HR1 domain, an HR2 domain, a TM, and a CD. In embodiments, the amino acids for each domain are shown in Figure 6A (shown according to SEQ ID NO:1) and Figure 6B (shown according to SEQ ID NO:2). In embodiments, each domain may have at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or at least 99.5% identity to the sequence of the respective domain in SEQ ID NO:1 or SEQ ID NO:2. Each domain may have up to about 1, up to about 2, up to about 3, up to about 4, up to about 5, up to about 10, up to about 20, or up to about 30 amino acid deletions, insertions, or mutations compared to the sequence shown in SEQ ID NO:1 or SEQ ID NO:2. Each domain may have up to about 1 to about 5 amino acids, up to about 3 to about 10 amino acids, up to about 5 to 10 amino acids, up to about 8 to 12 amino acids, up to about 10 to 15 amino acids, up to about 12 to 17 amino acids, up to about 15 to 20 amino acids, up to about 18 to 23 amino acids, up to about 20 to 25 amino acids, up to about 22 to 27 amino acids, up to about 25 to 30 amino acid deletions, insertions, or mutations compared to the sequence shown in SEQ ID NO:1 or SEQ ID NO:2. Note that Figures 2 and 3 show a 13 amino acid N-terminal signal peptide that is not present in the mature peptide. The CoV S polypeptide may be used to stimulate an immune response to a native CoV spike (S) polypeptide.

[0061] In embodiments, a naturally occurring CoV spike (S) polypeptide (SEQ ID NO:2) is modified to obtain a non-naturally occurring CoV spike (S) polypeptide.

[0062] In embodiments, a naturally occurring CoV spike (S) polypeptide (SEQ ID NO:2) is modified to obtain a non-naturally occurring CoV spike (S) polypeptide (FIG. 1). In embodiments, the CoV spike (S) glycoprotein comprises an S1 subunit and an S2 subunit, where the S1 subunit comprises the NTD, RBD, SD1 / 2, and an inactive furin cleavage site (amino acids 669-672), and the S2 subunit comprises mutations at amino acids 973 and 974; The NTD (amino acids 1-318) is optionally: (a) a deletion of one or more amino acids selected from the group consisting of amino acids 56, 57, 131, 132, 144, 145, 228, 229, 230, 231, 234, 235, 236, 237, 238, 239, 240, and combinations thereof; (b) insertion of 1, 2, 3, or 4 amino acids after amino acid 132; (c) one or more amino acid mutations selected from the group consisting of amino acids 5, 6, 7, 13, 39, 51, 53, 54, 56, 57, 62, 63, 67, 82, 125, 129, 131, 132, 133, 139, 143, 144, 145, 177, 200, 201, 202, 209, 229, 233, 240, 245, and combinations thereof; and comprising one or more modifications selected from the group consisting of: the RBD optionally comprises one or more amino acid mutations selected from the group consisting of amino acids 333, 404, 419, 426, 439, 440, 464, 465, 471, 477, 481, 488, and combinations thereof; The SD1 / 2 domain optionally comprises one or more amino acid mutations selected from the group consisting of 557, 600, 601, 642, 664, 668, and combinations thereof; The S2 subunit optionally comprises: (a) deletion of one or more amino acids from 676-685, 676-702, 702-711, 775-793, 806-815, and combinations thereof; (b) one or more amino acid mutations from 688, 703, 846, 875, 937, 969, 973, 974, 1014, 1058, 1105, and 1163, and combinations thereof; (c) deletion of one or more amino acids from the transmembrane and cytoplasmic domain (TMCT) (amino acids 1201 to 1260); and comprising one or more modifications selected from the group consisting of: The amino acids of the CoV S glycoprotein are numbered relative to SEQ ID NO:2.

[0063] In embodiments, the CoV S polypeptides described herein are in a prefusion conformation. In embodiments, the CoV S polypeptides described herein have a flexible HR2 domain. Unless otherwise indicated, domain flexibility is determined by transmission electron microscopy (TEM) and 2D class averaging. Reduced electron density corresponds to flexible domains.

[0064] Modifications to the S1 subunit In embodiments, the CoV S polypeptide comprises one or more modifications to the S1 subunit having the amino acid sequence of SEQ ID NO:121.

[0065] The amino acid sequence of the S1 subunit (SEQ ID NO:121) is shown below. QCVNLTTRTQLPPAYTNSFTRGVYYPDKVFRSSVLHSTQDLFLPFFSNVTWFHAIHVSGTNGTKRFDNPVLPFNDGVYFASTEKSNIIRGWIFGTTLDSKTQSLLIVNNATNVVIKVCEFQFCNDPFLGVYYHKNNKSWMESEFRVYSSANNCTFEYVSQPFLMDLEGKQGNFKNLREFVFKNIDGYFKIYSKHTPINLVRDLPQGFSALEPLVDLPIGINITRFQTLLALHRSYLTPGDSSSGWTAGAAAYYVGYLQPRTFLLKYNENGTITDAVDCALDPLSETKCTLKSFTVEKGIYQTSNFRVQPTESIVRFPNITNLCPFGEVFNATRFASVYAWNRKRISNCVADYSVLYNSASFSTFKCYGVSPTKLNDLCFTNVYADSFVIRGDEVRQIAPGQTGKIADYNYKLPDDFTGCVIAWNSNNLDSKVGGNYNYLYRLFRKSNLKPFERDISTEIYQAGSTPCNGVEGFNCYFPLQSYGFQPTNGVGYQPYRVVVLSFELLHAPATVCGPKKSTNLVKNKCVNFNFNGLTGTGVLTESNKKFLPFQQFGRDIADTTDAVRDPQTLEILDITPCSFGGVSVITPGTNTSNQVAVLYQDVNCTEVPVAIHADQLTPTWRVYSTGSNVFQTRAGCLIGAEHVNNSYECDIPIGAGICASYQTQTNSPRRAR

[0066] In embodiments, a CoV S polypeptide described herein comprises an S1 subunit having at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or at least 99.5% identity to the S1 subunit of SEQ ID NO:1 or SEQ ID NO:2. The S1 subunit can have up to about 1, up to about 2, up to about 3, up to about 4, up to about 5, up to about 10, up to about 15, up to about 20, up to about 25, or up to about 30 amino acid deletions, insertions, or mutations compared to the S1 subunit of SEQ ID NO:1 or SEQ ID NO:2. The S1 subunit may have deletions, insertions or mutations of up to about 1, up to about 2, about 1 to about 5 amino acids, about 3 to about 10 amino acids, about 5 to 10 amino acids, about 8 to 12 amino acids, about 10 to 15 amino acids, about 12 to 17 amino acids, about 15 to 20 amino acids, about 18 to 23 amino acids, about 20 to 25 amino acids, about 22 to about 27 amino acids, or about 25 to 30 amino acids compared to the S1 subunit of SEQ ID NO: 1 or SEQ ID NO: 2.

[0067] In embodiments, the S1 subunit may include any combination of the modifications shown in Table 1A. [Table 2-1] [Table 2-2] [Table 2-3] [Table 2-4] [Table 2-5]

[0068] Modifications to the S1 subunit-NTD In embodiments, the CoV S polypeptide comprises one or more modifications to the NTD. In embodiments, the NTD has the amino acid sequence of SEQ ID NO: 118, which corresponds to amino acids 14 to 305 of SEQ ID NO: 1 or amino acids 1 to 292 of SEQ ID NO: 2.

[0069] The amino acid sequence of the NTD (SEQ ID NO:118) is shown below. [ka]

[0070] The underlined region in SEQ ID NO:118 represents amino acids that may be modified within the NTD.

[0071] In embodiments, the NTD has the amino acid sequence of SEQ ID NO: 45, which corresponds to amino acids 14 to 331 of SEQ ID NO: 1 or amino acids 1 to 318 of SEQ ID NO: 2. The amino acid sequence of the NTD (SEQ ID NO: 45) is shown below.

[0072] [ka]

[0073] In embodiments, the NTD and RBD overlap by up to about 1 amino acid, up to about 5 amino acids, up to about 10 amino acids, or up to about 20 amino acids.

[0074] In embodiments, the NTDs provided herein can be extended at the C-terminus by up to 5, up to 10, up to 15, up to 20, up to 25, or up to 30 amino acids.

[0075] In embodiments, a CoV S polypeptide described herein comprises an NTD having at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or at least 99.5% identity to the NTD of SEQ ID NO:1 or SEQ ID NO:2. The NTD can have up to about 1, up to about 2, up to about 3, up to about 4, up to about 5, up to about 10, up to about 15, up to about 20, up to about 25, or up to about 30 amino acid deletions, insertions, or mutations compared to the amino acid sequence of the NTD of SEQ ID NO:1 or SEQ ID NO:2. The NTD may have deletions, insertions, or mutations of about 1 to about 5 amino acids, about 3 to about 10 amino acids, about 5 to 10 amino acids, about 8 to 12 amino acids, about 10 to 15 amino acids, about 12 to 17 amino acids, about 15 to 20 amino acids, about 18 to 23 amino acids, about 20 to 25 amino acids, about 22 to about 27 amino acids, or about 25 to 30 amino acids, compared to the amino acid sequence of the NTD of SEQ ID NO: 1 or SEQ ID NO: 2.

[0076] In embodiments, the CoV S polypeptide comprises a deletion of one or more amino acids from the N-terminal domain (NTD) (corresponding to amino acids 1-292 of SEQ ID NO:2). In embodiments, the CoV polypeptide comprises a deletion of about 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, 240, 250, 260, 270, 280, 290, or up to 292 amino acids of the NTD.

[0077] In embodiments, the CoV S polypeptide comprises a deletion of one or more amino acids from the NTD (corresponding to amino acids 1-318 of SEQ ID NO:2). In embodiments, the CoV S polypeptide comprises a deletion of amino acids 1-318 of the NTD of SEQ ID NO:2. In embodiments, the deletion of the NTD enhances protein expression of a CoV spike (S) polypeptide. In embodiments, the CoV S polypeptide having an NTD deletion has an amino acid sequence represented by SEQ ID NOs:46, 48, 49, 51, 52, and 54. In embodiments, the CoV S polypeptide having an NTD deletion is encoded by an isolated nucleic acid sequence selected from the group consisting of SEQ ID NO:47, SEQ ID NO:50, and SEQ ID NO:53.

[0078] In embodiments, the NTD may include any combination of the modifications shown in Table 1B. These modifications are shown for reference to the mature S polypeptide sequence of SEQ ID NO:2. [Table 3-1] [Table 3-2] [Table 3-3]

[0079] Modifications to the S1 subunit-RBD In embodiments, the CoV S polypeptide comprises one or more modifications to the RBD.

[0080] In embodiments, the RBD has the amino acid sequence of SEQ ID NO:126, which corresponds to amino acids 331 to 527 of SEQ ID NO:1 or amino acids 318 to 514 of SEQ ID NO:2.

[0081] The amino acid sequence of the RBD (SEQ ID NO: 126) is shown below. [ka]

[0082] The underlined regions in SEQ ID NO:126 represent amino acids within the RBD subunit that may be modified.

[0083] In embodiments, the RBD has the amino acid sequence of SEQ ID NO:116, which corresponds to amino acids 335 to 530 of SEQ ID NO:1 or amino acids 322 to 517 of SEQ ID NO:2.

[0084] The amino acid sequence of the RBD (SEQ ID NO:116) is shown below. LCPFGEVFNATRFASVYAWNRKRISNCVADYSVLYNSASFSTFKCYGVSPTKLNDLCFTNVYADSFVIRGDEVRQIAPGQTGKIADYNYKLPDDFTGCVIAWNSNNLDSKVGGNYNYLYRLFRKSNLKPFERDISTEIYQAGSTPCNGVEGFNCYFPLQSYGFQPTNGVGYQPYRVVVLSFELLHAPATVCGPKKS

[0085] In embodiments, the RBDs provided herein can be extended at the N- or C-terminus by up to 1 amino acid, up to 5 amino acids, up to 10 amino acids, up to 15 amino acids, up to 20 amino acids, up to 25 amino acids, or up to 30 amino acids.

[0086] In embodiments, the CoV S polypeptides described herein comprise an RBD having at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or at least 99.5% identity to the RBD of SEQ ID NO:1 or SEQ ID NO:2. The RBD may have up to about 1, up to about 2, up to about 3, up to about 4, up to about 5, up to about 10, up to about 15, up to about 20, up to about 25, or up to about 30 amino acid deletions, insertions, or mutations compared to the amino acid sequence of the RBD of SEQ ID NO:1 or SEQ ID NO:2. The RBD may have deletions, insertions, or mutations of about 1 to about 5 amino acids, about 3 to about 10 amino acids, about 5 to 10 amino acids, about 8 to 12 amino acids, about 10 to 15 amino acids, about 12 to 17 amino acids, about 15 to 20 amino acids, about 18 to 23 amino acids, about 20 to 25 amino acids, about 22 to about 27 amino acids, or about 25 to 30 amino acids compared to the amino acid sequence of the RBD of SEQ ID NO:1 or SEQ ID NO:2.

[0087] In embodiments, the CoV S polypeptide has at least 1, at least 2, at least 3, at least 4, at least 4, at least 5, at least 6, at least 7, at least 8, at least 9, at least 10, at least 11, at least 12, at least 13, at least 14, at least 15, at least 16, at least 17, at least 18, at least 19, or at least 20 mutations in the RBD. In embodiments, the RBD may include any combination of modifications shown in Table 1C. [Table 4-1] [Table 4-2]

[0088] Modifications to SD1 / 2 In embodiments, the CoV S polypeptide comprises one or more modifications to SD1 / 2 having the amino acid sequence of SEQ ID NO:122, which corresponds to amino acids 542 to 681 of SEQ ID NO:1 or amino acids 529 to 668 of SEQ ID NO:2.

[0089] The amino acid sequence of SD1 / 2 (SEQ ID NO: 122) is shown below. NFNGLTGTGVLTESNKKFLPFQQFGRDIADTTDAVRDPQTLEILDITPCSFGGVSVITPGTNTSNQVAVLYQDVNCTEVPVAIHADQLTPTWRVYSTGSNVFQTRAGCLIGAEHVNNSYECDIPIGAGICASYQTQTNSP

[0090] In embodiments, the CoV S polypeptides described herein comprise an SD1 / 2 that has at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or at least 99.5% identity to SD1 / 2 of SEQ ID NO:1 or SEQ ID NO:2. SD1 / 2 can have up to about 1, up to about 2, up to about 3, up to about 4, up to about 5, up to about 10, up to about 15, up to about 20, up to about 25, or up to about 30 amino acid deletions, insertions, or mutations compared to the amino acid sequence of SD1 / 2 of SEQ ID NO:1 or SEQ ID NO:2. Compared with the amino acid sequence of SD1 / 2 of SEQ ID NO:1 or SEQ ID NO:2, SD1 / 2 may have deletions, insertions, or mutations of about 1 to about 5 amino acids, about 3 to about 10 amino acids, about 5 to 10 amino acids, about 8 to 12 amino acids, about 10 to 15 amino acids, about 12 to 17 amino acids, about 15 to 20 amino acids, about 18 to 23 amino acids, about 20 to 25 amino acids, about 22 to about 27 amino acids, or about 25 to 30 amino acids.

[0091] In embodiments, the CoV S polypeptide has at least 1, at least 2, at least 3, at least 4, at least 4, at least 5, at least 6, at least 7, at least 8, at least 9, at least 10, at least 11, at least 12, at least 13, at least 14, at least 15, at least 16, at least 17, at least 18, at least 19, or at least 20 mutations in SD1 / 2. In embodiments, SD1 / 2 may include any combination of modifications shown in Table ID. [Table 5]

[0092] Modifications to the furin cleavage site In embodiments, the CoV S polypeptide comprises a furin site (RRAR) corresponding to amino acids 682-685 of SEQ ID NO:1 or amino acids 669-672 of SEQ ID NO:2 that is inactivated by one or more mutations. Inactivation of the furin cleavage site prevents furin from cleaving the CoV S polypeptide. In embodiments, the CoV S polypeptides described herein that contain an inactivated furin cleavage site are represented as a single chain.

[0093] In embodiments, one or more of the amino acids that make up the natural furin cleavage site are mutated to any natural amino acid. In embodiments, the amino acid is an L-amino acid. Non-limiting examples of amino acids include alanine, arginine, glycine, asparagine, aspartic acid, cysteine, glutamine, glutamic acid, serine, threonine, histidine, lysine, methionine, proline, valine, isoleucine, leucine, tyrosine, tryptophan, and phenylalanine.

[0094] In an embodiment, one or more amino acids that make up the natural furin cleavage site are mutated to glutamine. In an embodiment, one, two, three or four amino acids are mutated to glutamine. In an embodiment, one of the arginines that make up the natural furin cleavage site is mutated to glutamine. In an embodiment, two of the arginines that make up the natural furin cleavage site are mutated to glutamine. In an embodiment, three of the arginines that make up the natural furin cleavage site are mutated to glutamine.

[0095] In an embodiment, one or more amino acids that make up the natural furin cleavage site are mutated to alanine. In an embodiment, one, two, three, or four amino acids may be mutated to alanine. In an embodiment, one of the arginines that make up the natural furin cleavage site is mutated to alanine. In an embodiment, two of the arginines that make up the natural furin cleavage site are mutated to alanine. In an embodiment, three of the arginines that make up the natural furin cleavage site are mutated to alanine.

[0096] In an embodiment, one or more amino acids that make up the natural furin cleavage site are mutated to glycine. In an embodiment, one, two, three or four amino acids are mutated to glycine. In an embodiment, one of the arginines of the natural furin cleavage site is mutated to glycine. In an embodiment, two of the arginines that make up the natural furin cleavage site are mutated to glycine. In an embodiment, three of the arginines that make up the natural furin cleavage site are mutated to glycine.

[0097] In an embodiment, one or more amino acids that make up the natural furin cleavage site are mutated to asparagine. For example, one, two, three or four amino acids are mutated to asparagine. In an embodiment, one of the arginines that make up the natural furin cleavage site is mutated to asparagine. In an embodiment, two of the arginines that make up the natural furin cleavage site are mutated to asparagine. In an embodiment, three of the arginines that make up the natural furin cleavage site are mutated to asparagine.

[0098] Non-limiting examples of amino acid sequences of inactivated furin sites contained within a CoV S polypeptide are found in Table 1E. [Table 6]

[0099] In embodiments, instead of an active furin cleavage site (SEQ ID NO: 6), the CoV S polypeptide described herein comprises an inactivated furin cleavage site. In embodiments, the amino acid sequence of the inactivated furin cleavage site is represented by any one of SEQ ID NOs: 7-34 or SEQ ID NO: 97. In embodiments, the amino acid sequence of the inactivated furin cleavage site is QQAQ (SEQ ID NO: 7). In embodiments, the amino acid sequence of the inactivated furin cleavage site is GSAS (SEQ ID NO: 97). In embodiments, the amino acid sequence of the inactivated furin cleavage site is GSGA (SEQ ID NO: 111). In embodiments, the amino acid sequence of the inactivated furin cleavage site is GG, GGG (SEQ ID NO: 127), GGGG (SEQ ID NO: 128), or GGGGG (SEQ ID NO: 129).

[0100] Modifications to the S2 subunit In embodiments, the CoV S polypeptide comprises one or more modifications to an S2 subunit having the amino acid sequence of SEQ ID NO:120, which corresponds to amino acids 686 to 1273 of SEQ ID NO:1 or amino acids 673 to 1260 of SEQ ID NO:2.

[0101] The amino acid sequence of the S2 subunit (SEQ ID NO:120) is shown below. SVASQSIIAYTMSLGAENSVAYSNNSIAIPTNFTISVTTEILPVSMTKTSVDCTMYICGDSTECSNLLLQYGSFCTQLNRALTGIAVEQDKNTQEVFAQVKQIYKTPPIKDFGGFNFSQILPDPSKPSKRSFIEDLLFNKVTLADAG FIKQYGDCLGDIAARDLICAQKFNGLTVLPPLLTDEMIAQYTSALLAGTITSGWTFGAGAALQIPFAMQMAYRFNGIGVTQNVLYENQKLIANQFNSAIGKIQDSLSSTASALGKLQDVVNQNAQALNTLVKQLSSNFGAISSVLND ILSRLDKVEAEVQIDRLITGRLQSLQTYVTQQLIRAAEIRASANLAATKMSECVLGQSKRVDFCGKGYHLMSFPQSAPHGVVFLHVTYVPAQEKNFTTAPAICHDGKAHFPREGVFVSNGTHWFVTQRNFYEPQIITTDNTFVSGNC DVVIGIVNNTVYDPLQPELDSFKEELDKYFKNHTSPDVDLGDISGINASVVNIQKEIDRLNEVAKNLNESLIDLQELGKYEQYIKWPWYIWLGFIAGLIAIVMVTIMLCCMTSCCSCLKGCCSCGSCCKFDEDDSEPLVLKGVKLHYT

[0102] In embodiments, a CoV S polypeptide described herein comprises an S2 subunit having at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or at least 99.5% identity to the S2 subunit of SEQ ID NO:1 or SEQ ID NO:2. The S2 subunit can have up to about 1, up to about 2, up to about 3, up to about 4, up to about 5, up to about 10, up to about 15, up to about 20, up to about 25, or up to about 30 amino acid deletions, insertions, or mutations compared to the amino acid sequence of the S2 subunit of SEQ ID NO:1 or SEQ ID NO:2. The S2 subunit may have deletions, insertions, or mutations of about 1 to about 5 amino acids, about 3 to about 10 amino acids, about 5 to 10 amino acids, about 8 to 12 amino acids, about 10 to 15 amino acids, about 12 to 17 amino acids, about 15 to 20 amino acids, about 18 to 23 amino acids, about 20 to 25 amino acids, about 22 to about 27 amino acids, or about 25 to 30 amino acids, compared to the amino acid sequence of the S2 subunit of SEQ ID NO:1 or SEQ ID NO:2.

[0103] In embodiments, the S2 subunit may include any combination of the modifications shown in Table 1F. [Table 7-1] [Table 7-2]

[0104] In embodiments, the CoV S polypeptide comprises a deletion corresponding to one or more deletions within amino acids 676-685 of a naturally occurring CoV spike (S) polypeptide (SEQ ID NO:2). In embodiments, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 amino acids are deleted within amino acids 676-685 of a naturally occurring CoV spike (S) polypeptide (SEQ ID NO:2). In embodiments, the deletion of amino acids within amino acids 676-685 is contiguous, e.g., amino acids 676 and 677 are deleted, or amino acids 680 and 681 are deleted. In embodiments, the deletion of amino acids within amino acids 676-685 is non-contiguous, e.g., amino acids 676 and 680 are deleted, or amino acids 677 and 682 are deleted. In embodiments, the CoV S polypeptide comprising a deletion corresponding to one or more deletions within amino acids 676-685 has an amino acid sequence selected from the group consisting of SEQ ID NO:62 and SEQ ID NO:63.

[0105] In embodiments, the CoV S polypeptide comprises a deletion corresponding to one or more deletions within amino acids 702-711 of a naturally occurring CoV spike (S) polypeptide (SEQ ID NO:2). In embodiments, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 amino acids are deleted within amino acids 702-711 of a naturally occurring SARS-CoV-2 spike (S) polypeptide (SEQ ID NO:2). In embodiments, the one or more deletions of amino acids within amino acids 702-711 are contiguous, e.g., amino acids 702 and 703 are deleted, or amino acids 708 and 709 are deleted. In embodiments, the deletions of amino acids within amino acids 702-711 are non-contiguous, e.g., amino acids 702 and 704 are deleted, or amino acids 707 and 710 are deleted. In embodiments, the CoV S polypeptide including a deletion corresponding to one or more deletions within amino acids 702-711 has an amino acid sequence selected from the group consisting of SEQ ID NO:64 and SEQ ID NO:65.

[0106] In embodiments, the CoV S polypeptide comprises a deletion corresponding to one or more deletions within amino acids 775-793 of a naturally occurring CoV polypeptide (SEQ ID NO:2). In embodiments, about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, or up to 19 amino acids of amino acids 775-793 of a naturally occurring SARS-CoV-2 spike (S) polypeptide (SEQ ID NO:2) are deleted. In embodiments, the one or more deletions of amino acids within amino acids 775-793 are contiguous, e.g., amino acids 776 and 777 are deleted, or amino acids 780 and 781 are deleted. In embodiments, the deletions of amino acids within amino acids 775-793 are non-contiguous, e.g., amino acids 775 and 790 are deleted, or amino acids 777 and 781 are deleted.

[0107] In embodiments, the CoV S polypeptide comprises a deletion of the fusion peptide corresponding to amino acids 806-815 of SEQ ID NO:2 (SEQ ID NO:104). In embodiments, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 amino acids are deleted from the fusion peptide of the CoV spike (S) polypeptide (SEQ ID NO:2). In embodiments, the deletion of amino acids in the fusion peptide is contiguous, e.g., amino acids 806 and 807 are deleted, or amino acids 809 and 810 are deleted. In embodiments, the deletion of amino acids in the fusion peptide is non-contiguous, e.g., amino acids 806 and 808 are deleted, or amino acids 810 and 813 are deleted. In embodiments, the CoV S polypeptide comprising a deletion corresponding to one or more amino acids of the fusion peptide has an amino acid sequence selected from SEQ ID NOs:66, 77, and 105-108.

[0108] In embodiments, the CoV S polypeptide comprises a mutation at Lys-973 of a native CoV spike (S) polypeptide (SEQ ID NO: 2). In embodiments, Lys-973 is mutated to any native amino acid. In embodiments, Lys-973 is mutated to proline. In embodiments, Lys-973 is mutated to glycine. In embodiments, the CoV S polypeptide comprising a mutation at amino acid 973 is selected from the group consisting of SEQ ID NOs: 84-89, 105-106, and 109-110.

[0109] In embodiments, the CoV S polypeptide comprises a mutation at Val-974 of a naturally occurring CoV spike (S) polypeptide (SEQ ID NO: 2). In embodiments, Val-974 is mutated to any naturally occurring amino acid. In embodiments, Val-974 is mutated to proline. In embodiments, Val-974 is mutated to glycine. In embodiments, the CoV S polypeptide comprising a mutation at amino acid 974 is selected from the group consisting of SEQ ID NOs: 84-89, 105-106, and 109-110.

[0110] In embodiments, the CoV S polypeptide comprises a mutation at Lys-973 and Val-974 of a naturally occurring CoV spike (S) polypeptide (SEQ ID NO: 2). In embodiments, Lys-973 and Val-974 are mutated to any naturally occurring amino acid. In embodiments, Lys-973 and Val-974 are mutated to proline. In embodiments, the CoV S polypeptide comprising a mutation at amino acids 973 and 974 is selected from SEQ ID NOs: 84-89, 105-106, and 109-110. Modifications to the S2 subunit HR1 domain

[0111] In embodiments, the CoV S polypeptide comprises one or more modifications to the HR1 domain having the amino acid sequence of SEQ ID NO:119, which corresponds to amino acids 912 to 984 of SEQ ID NO:1 or amino acids 889 to 971 of SEQ ID NO:2.

[0112] The amino acid sequence of the HR1 domain (SEQ ID NO:119) is shown below. MAYRFNGIGVTQNVLYENQKLIANQFNSAIGKIQDSLSSTASALGKLQDVVNQNAQALNTLVKQLSSNFGAISSVLNDILSRL

[0113] In embodiments, a CoV S polypeptide described herein comprises an HR1 domain having at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or at least 99.5% identity to the HR1 domain of SEQ ID NO:1 or SEQ ID NO:2. The HR1 domain can have up to about 1, up to about 2, up to about 3, up to about 4, up to about 5, up to about 10, up to about 15, up to about 20, up to about 25, or up to about 30 amino acid deletions, insertions, or mutations compared to the amino acid sequence of the HR1 domain of SEQ ID NO:1 or SEQ ID NO:2. The HR1 domain may have deletions, insertions, or mutations of about 1 to about 5 amino acids, about 3 to about 10 amino acids, about 5 to 10 amino acids, about 8 to 12 amino acids, about 10 to 15 amino acids, about 12 to 17 amino acids, about 15 to 20 amino acids, about 18 to 23 amino acids, about 20 to 25 amino acids, about 22 to about 27 amino acids, or about 25 to 30 amino acids, compared to the amino acid sequence of the HR1 domain of SEQ ID NO: 1 or SEQ ID NO: 2.

[0114] In embodiments, the HR1 domain may include any combination of the modifications shown in Table 1G. [Table 8]

[0115] Modifications to the S2 subunit HR2 domain In embodiments, the CoV S polypeptide comprises one or more modifications to the HR2 domain having the amino acid sequence of SEQ ID NO:125, which corresponds to amino acids 1163 to 1213 of SEQ ID NO:1 or amino acids 1150 to 1200 of SEQ ID NO:2.

[0116] The amino acid sequence of the HR2 domain (SEQ ID NO: 125) is shown below. DVDLGDISGINASVVNIQKEIDRLNEVAKNLNESLIDLQELGKYEQYIKWP

[0117] In embodiments, the CoV S polypeptides described herein comprise an HR2 domain having at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or at least 99.5% identity to the HR2 domain of SEQ ID NO:1 or SEQ ID NO:2. The HR2 domain can have up to about 1, up to about 2, up to about 3, up to about 4, up to about 5, up to about 10, up to about 15, up to about 20, up to about 25, or up to about 30 amino acid deletions, insertions, or mutations compared to the amino acid sequence of the HR2 domain of SEQ ID NO:1 or SEQ ID NO:2. The HR2 domain may have deletions, insertions, or mutations of about 1 to about 5 amino acids, about 3 to about 10 amino acids, about 5 to 10 amino acids, about 8 to 12 amino acids, about 10 to 15 amino acids, about 12 to 17 amino acids, about 15 to 20 amino acids, about 18 to 23 amino acids, about 20 to 25 amino acids, about 22 to about 27 amino acids, or about 25 to 30 amino acids compared to the amino acid sequence of the HR2 domain of SEQ ID NO: 1 or SEQ ID NO: 2.

[0118] Modifications to TM domains In embodiments, the CoV S polypeptide comprises one or more modifications to a TM domain having the amino acid sequence of SEQ ID NO:123, which corresponds to amino acids 1214 to 1237 of SEQ ID NO:1 or amino acids 1201 to 1224 of SEQ ID NO:2.

[0119] The amino acid sequence of the TM domain (SEQ ID NO: 123) is shown below. WYIWLGFIAGLIAIVMVTIMLCCM

[0120] In embodiments, the CoV S polypeptides described herein comprise a TM domain having at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or at least 99.5% identity to the TM domain of SEQ ID NO:1 or SEQ ID NO:2. The TM domain can have up to about 1, up to about 2, up to about 3, up to about 4, up to about 5, up to about 10, up to about 15, up to about 20, up to about 25, or up to about 30 amino acid deletions, insertions, or mutations compared to the amino acid sequence of the TM domain of SEQ ID NO:1 or SEQ ID NO:2. The TM domain may have deletions, insertions, or mutations of about 1 to about 5 amino acids, about 3 to about 10 amino acids, about 5 to 10 amino acids, about 8 to 12 amino acids, about 10 to 15 amino acids, about 12 to 17 amino acids, about 15 to 20 amino acids, about 18 to 23 amino acids, about 20 to 25 amino acids, about 22 to about 27 amino acids, or about 25 to 30 amino acids compared to the amino acid sequence of the TM domain of SEQ ID NO:1 or SEQ ID NO:2.

[0121] In embodiments, the CoV S polypeptides described herein lack the entire TM domain. In embodiments, the CoV S polypeptides include a TM domain.

[0122] Modifications to CT In embodiments, the CoV S polypeptide comprises one or more modifications to a CT having the amino acid sequence of SEQ ID NO:124, which corresponds to amino acids 1238 to 1273 of SEQ ID NO:1 or amino acids 1225 to 1260 of SEQ ID NO:2.

[0123] The amino acid sequence of CT (SEQ ID NO: 124) is shown below. TSCCSCLKGCCSCGSCCKFDEDDSEPVLKGVKLHYT

[0124] In embodiments, a CoV S polypeptide described herein comprises a CT having at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or at least 99.5% identity to the CT of SEQ ID NO:1 or SEQ ID NO:2. The CT may have up to about 1, up to about 2, up to about 3, up to about 4, up to about 5, up to about 10, up to about 15, up to about 20, up to about 25, or up to about 30 amino acid deletions, insertions, or mutations compared to the amino acid sequence of the CT of SEQ ID NO:1 or SEQ ID NO:2. Compared to the amino acid sequence of CT in SEQ ID NO:1 or SEQ ID NO:2, CT may have deletions, insertions, or mutations of about 1 to about 5 amino acids, about 3 to about 10 amino acids, about 5 to 10 amino acids, about 8 to 12 amino acids, about 10 to 15 amino acids, about 12 to 17 amino acids, about 15 to 20 amino acids, about 18 to 23 amino acids, about 20 to 25 amino acids, about 22 to about 27 amino acids, or about 25 to 30 amino acids.

[0125] In embodiments, the CoV S polypeptide described herein lacks a CT. In embodiments, the CoV S polypeptide comprises a CT.

[0126] In an embodiment, the CoV S polypeptide comprises a TM and a CT. In an embodiment, the CoV spike (S) polypeptide comprises a deletion of one or more amino acids from the transmembrane and cytoplasmic tail (TMCT) (corresponding to amino acids 1201-1260). The amino acid sequence of the TMCT is represented by SEQ ID NO: 39. In an embodiment, the CoV S polypeptide having a deletion of one or more residues of the TMCT has enhanced protein expression. In an embodiment, the CoV spike (S) polypeptide having one or more deletions from the TMCT has an amino acid sequence selected from the group consisting of SEQ ID NOs: 40, 41, 42, 52, 54, 59, 61, 88, and 89. In an embodiment, the CoV S polypeptide having one or more deletions from the TM-CD is encoded by an isolated nucleic acid sequence selected from the group consisting of SEQ ID NOs: 39, 43, 53, and 60. Exemplary Non-Naturally Occurring CoV S Polypeptides or Nanoparticles

[0127] In embodiments, the CoV S polypeptide comprises a deletion of amino acids 56 and 57 of the native CoV spike (S) polypeptide (SEQ ID NO:2).

[0128] In embodiments, the CoV S polypeptide comprises a deletion of amino acids 131 and 132 of the native CoV spike (S) polypeptide (SEQ ID NO:2).

[0129] In embodiments, the CoV S polypeptide comprises a deletion of amino acids 56 and 131 of the naturally occurring CoV spike (S) polypeptide (SEQ ID NO:2). In embodiments, the CoV S polypeptide comprises a deletion of amino acids 57 and 131 of the naturally occurring CoV spike (S) polypeptide (SEQ ID NO:2).

[0130] In embodiments, the CoV S polypeptide comprises a deletion of amino acids 56, 57, and 131 of the native CoV spike (S) polypeptide (SEQ ID NO:2).

[0131] In embodiments, the CoV S polypeptide comprises a deletion of amino acids 56 and 132 of the native CoV spike (S) polypeptide (SEQ ID NO:2).

[0132] In embodiments, the CoV S polypeptide comprises a deletion of amino acids 57 and 132 of the native CoV spike (S) polypeptide (SEQ ID NO:2).

[0133] In embodiments, the CoV S polypeptide comprises a deletion of amino acids 56, 57, and 132 of the native CoV spike (S) polypeptide (SEQ ID NO:2).

[0134] In embodiments, the CoV S polypeptide comprises a deletion of amino acids 56, 57, 131, and 132 of the native CoV spike (S) polypeptide (SEQ ID NO:2).

[0135] In embodiments, the CoV S polypeptide comprises a mutation that stabilizes the prefusion conformation of the CoV S polypeptide. In embodiments, the CoV S polypeptide comprises a proline or glycine substitution that stabilizes the prefusion conformation. This strategy was utilized to develop a prefusion stabilized MERS-CoV S protein as described in the following documents, which are incorporated herein by reference in their entirety: Proc Natl Acad Sci USA. 2017 Aug 29; 114(35): E7348-E7357; Sci Rep. 2018 Oct 24; 8(1): 15701; U.S. Patent Application Publication No. 2020 / 0061185; PCT Application No. PCT / US2017 / 058370.

[0136] In embodiments, the CoV S polypeptide comprises a mutation of Lys-973 and Val-974 to proline and an inactivated furin cleavage site. In embodiments, the CoV S polypeptide comprises a mutation of Lys-973 and Val-974 to proline and an inactivated furin cleavage site having an amino acid sequence of QQAQ (SEQ ID NO:7) or GSAS (SEQ ID NO:96). An exemplary CoV S polypeptide comprising a mutation of Lys-973 and Val-974 to proline and an inactivated furin cleavage site is shown in Figure 3. In embodiments, the CoV S polypeptide comprising a mutation of Lys-973 and Val-974 to proline and an inactivated furin cleavage site has an amino acid sequence of SEQ ID NO:86 or 87 and a nucleic acid sequence of SEQ ID NO:96.

[0137] In embodiments, the CoV S polypeptide comprises a mutation of Lys-973 and Val-974, an inactivated furin cleavage site, and a deletion of one or more amino acids of the fusion peptide. In embodiments, the CoV S polypeptide comprises a mutation of Lys-973 and Val-974 to proline, an inactivated furin cleavage site having an amino acid sequence of QQAQ (SEQ ID NO:7) or GSAS (SEQ ID NO:96), and a deletion of one or more amino acids of the fusion peptide. In embodiments, the CoV S polypeptide comprising a mutation of Lys-973 and Val-974, an inactivated furin cleavage site, and a deletion of one or more amino acids of the fusion peptide has SEQ ID NO:105 or 106. In embodiments, the CoV S polypeptide comprises, relative to a native CoV spike (S) polypeptide (SEQ ID NO:2), a Leu-5 to phenylalanine mutation, a Thr-7 to asparagine mutation, a Pro-13 to serine mutation, a Asp-125 to tyrosine mutation, an Arg-177 to serine mutation, a Lys-404 to threonine mutation, a Glu-471 to lysine mutation, an Asn-488 to tyrosine mutation, a His-642 to tyrosine mutation, a Thr-1014 to isoleucine mutation, Lys-973 and Val-974 to proline mutations, and an inactivated furin cleavage site having the amino acid sequence of QQAQ (SEQ ID NO:7) or GSAS (SEQ ID NO:96).

[0138] In embodiments, the CoV S polypeptide comprises, relative to a native CoV spike (S) polypeptide (SEQ ID NO:2), a mutation of Trp-139 to cysteine, a mutation of Leu-439 to arginine, a mutation of Lys-973 and Val-974 to proline, and an inactivated furin cleavage site having the amino acid sequence of QQAQ (SEQ ID NO:7) or GSAS (SEQ ID NO:96). In embodiments, the CoV S comprises, relative to a native CoV spike (S) polypeptide (SEQ ID NO:1), a mutation of Trp-152 to cysteine, a mutation of Leu-452 to arginine, a mutation of Ser-13 to isoleucine, a mutation of Lys-986 and Val-987 to proline, and an inactivated furin cleavage site having the amino acid sequence of QQAQ (SEQ ID NO:7) or GSAS (SEQ ID NO:96).

[0139] In embodiments, the CoV S polypeptide comprises, relative to a native CoV spike (S) polypeptide (SEQ ID NO:2), a mutation of Lys-404 to threonine or asparagine, a mutation of Glu-471 to lysine, a mutation of Asn-488 to tyrosine, a mutation of Leu-5 to phenylalanine, a mutation of Asp-67 to alanine, a mutation of Asp-202 to glycine, a deletion of one or more of amino acids 229-231, a mutation of Arg-233 ​​to isoleucine, mutations of Lys-973 and Val-974 to proline, and an inactivated furin cleavage site having the amino acid sequence of QQAQ (SEQ ID NO:7) or GSAS (SEQ ID NO:96).

[0140] In embodiments, the CoV S comprises an inactivated furin cleavage site having an amino acid sequence of QQAQ (SEQ ID NO:7) or GSAS (SEQ ID NO:96) with respect to a native CoV spike (S) polypeptide (SEQ ID NO:2), with Asn-488 mutated to tyrosine, Lys-973 and Val-974 mutated to proline, and QQAQ (SEQ ID NO:7) or GSAS (SEQ ID NO:96). In embodiments, the CoV S polypeptide having an inactivated furin cleavage site having an amino acid sequence of QQAQ (SEQ ID NO:7) or GSAS (SEQ ID NO:96) with Asn-488 mutated to tyrosine, Lys-973 and Val-974 mutated to proline, and QQAQ (SEQ ID NO:7) or GSAS (SEQ ID NO:96) comprises the amino acid sequence of SEQ ID NO:112.

[0141] In embodiments, the CoV S comprises a mutation of Asp-601 to glycine, a mutation of Asn-488 to tyrosine, a mutation of Lys-973 and Val-974 to proline, and an inactivated furin cleavage site having the amino acid sequence of QQAQ (SEQ ID NO:7) or GSAS (SEQ ID NO:96) compared to a native CoV spike (S) polypeptide (SEQ ID NO:2). In embodiments, the CoV S polypeptide having a mutation of Asn-488 to tyrosine, a mutation of Lys-973 and Val-974 to proline, and an inactivated furin cleavage site having the amino acid sequence of QQAQ (SEQ ID NO:7) or GSAS (SEQ ID NO:96) comprises the amino acid sequence of SEQ ID NO:113.

[0142] In embodiments, the CoV S polypeptide comprises, relative to a native CoV spike (S) polypeptide (SEQ ID NO:2), a deletion of amino acids 56, 57, and 131, a mutation of Asn-488 to tyrosine, a mutation of Ala-557 to aspartic acid, a mutation of Asp-601 to glycine, a mutation of Pro-668 to histidine, a mutation of Thr-703 to isoleucine, a mutation of Ser-969 to alanine, a mutation of Asp-1105 to histidine, mutations of Lys-973 and Val-974 to proline, and an inactivated furin cleavage site having the amino acid sequence QQAQ (SEQ ID NO:7), GSAS (SEQ ID NO:96), or GG. In embodiments, a CoV S polypeptide having a deletion of amino acids 56, 57, and 131, a mutation of Asn-488 to tyrosine, a mutation of Ala-557 to aspartic acid, a mutation of Asp-601 to glycine, a mutation of Pro-668 to histidine, a mutation of Thr-703 to isoleucine, a mutation of Ser-969 to alanine, a mutation of Asp-1105 to histidine, a mutation of Lys-973 and Val-974 to proline, and an inactivated furin cleavage site having the amino acid sequence of QQAQ (SEQ ID NO:7) or GSAS (SEQ ID NO:96), comprises the amino acid sequence of SEQ ID NO:114. In embodiments, a CoV S polypeptide having a deletion of amino acids 56, 57, and 131, a mutation of Asn-488 to tyrosine, a mutation of Ala-557 to aspartic acid, a mutation of Asp-601 to glycine, a mutation of Pro-668 to histidine, a mutation of Thr-703 to isoleucine, a mutation of Ser-969 to alanine, a mutation of Asp-1105 to histidine, mutations of Lys-973 and Val-974 to proline, and an inactivated furin cleavage site having the amino acid sequence of QQAQ (SEQ ID NO:7) or GSAS (SEQ ID NO:96) or GG comprises the amino acid sequence of SEQ ID NO:136.In embodiments, a CoV S polypeptide having a deletion of amino acids 56, 57, and 131, a mutation of Asn-488 to tyrosine, a mutation of Ala-557 to aspartic acid, a mutation of Asp-601 to glycine, a mutation of Pro-668 to histidine, a mutation of Thr-703 to isoleucine, a mutation of Ser-969 to alanine, a mutation of Asp-1105 to histidine, a mutation of Lys-973 and Val-974 to proline, and an inactivated furin cleavage site having an amino acid sequence of GG comprises SEQ ID NO: 137 or SEQ ID NO: 138. In some embodiments, a CoV S polypeptide having an amino acid sequence of SEQ ID NO: 114 or SEQ ID NO: 136 is encoded by a nucleic acid having a nucleic acid sequence of SEQ ID NO: 135. In some embodiments, a CoV S polypeptide having an amino acid sequence of SEQ ID NO: 137 or SEQ ID NO: 138 is encoded by a nucleic acid having a sequence of SEQ ID NO: 139.

[0143] In embodiments, the CoV S polypeptide comprises, relative to a native CoV spike (S) polypeptide (SEQ ID NO:2), a deletion of amino acids 56, 57, and 132, a mutation of Asn-488 to tyrosine, a mutation of Ala-557 to aspartic acid, a mutation of Asp-601 to glycine, a mutation of Pro-668 to histidine, a mutation of Thr-703 to isoleucine, a mutation of Ser-969 to alanine, a mutation of Asp-1105 to histidine, mutations of Lys-973 and Val-974 to proline, and an inactivated furin cleavage site having the amino acid sequence of QQAQ (SEQ ID NO:7) or GSAS (SEQ ID NO:96). In embodiments, a CoV S polypeptide having a deletion of amino acids 56, 57, and 132, a mutation of Asn-488 to tyrosine, a mutation of Ala-557 to aspartic acid, a mutation of Asp-601 to glycine, a mutation of Pro-668 to histidine, a mutation of Thr-703 to isoleucine, a mutation of Ser-969 to alanine, a mutation of Asp-1105 to histidine, a mutation of Lys-973 and Val-974 to proline, and an inactivated furin cleavage site having the amino acid sequence of QQAQ (SEQ ID NO:7) or GSAS (SEQ ID NO:96), comprises the amino acid sequence of SEQ ID NO:114.

[0144] In embodiments, compared to a native CoV spike (S) polypeptide (SEQ ID NO:2), the CoV S polypeptide comprises an Asn-488 to tyrosine mutation, an Asp-67 to alanine mutation, a Leu-229 to histidine mutation, an Asp-202 to glycine mutation, a Lys-404 to asparagine mutation, a Glu-471 to lysine mutation, an Ala-688 to valine mutation, an Asp-601 to glycine mutation, Lys-973 and Val-974 to prolines mutations, and an inactivated furin cleavage site having the amino acid sequence of QQAQ (SEQ ID NO:7) or GSAS (SEQ ID NO:96). In embodiments, a CoV S polypeptide having an Asn-488 mutation to tyrosine, an Asp-67 mutation to alanine, a Leu-229 mutation to histidine, an Asp-202 mutation to glycine, a Lys-404 mutation to asparagine, a Glu-471 mutation to lysine, an Ala-688 mutation to valine, an Asp-601 mutation to glycine, Lys-973 and Val-974 mutations to prolines, and an inactivated furin cleavage site having the amino acid sequence of QQAQ (SEQ ID NO:7) or GSAS (SEQ ID NO:96), comprises the amino acid sequence of SEQ ID NO:115.

[0145] In embodiments, the CoV S polypeptide comprises one or more modifications selected from K973P, V974P, an inactivated furin cleavage site, a deletion of amino acid 56, a deletion of amino acid 57, a deletion of amino acid 131, N488Y, A557D, D601G, P668H, T703I, S969A, and D1105H, where the amino acids are numbered relative to a CoV S polypeptide having the sequence of SEQ ID NO: 2. In embodiments, the inactivated furin cleavage site has an amino acid sequence of QQAQ (SEQ ID NO: 7). In embodiments, the inactivated furin cleavage site has an amino acid sequence of GG.

[0146] In embodiments, the CoV S polypeptide comprises one or more modifications selected from K973P, V974P, an inactivated furin cleavage site, D67A, D202G, L229H, K404N, E471K, N488Y, D601G, and A688V, where the amino acids are numbered relative to a CoV S polypeptide having the sequence of SEQ ID NO: 2. In embodiments, the inactivated furin cleavage site has an amino acid sequence of QQAQ (SEQ ID NO: 7). In embodiments, the inactivated furin cleavage site has an amino acid sequence of GG.

[0147] In embodiments, the CoV S polypeptide comprises one or more modifications selected from K973P, V974P, an inactivated furin cleavage site, a deletion of amino acids 229-231, D67A, D202G, K404N, E471K, N488Y, D601G, and A688V, where the amino acids are numbered relative to a CoV S polypeptide having the sequence of SEQ ID NO:2.

[0148] In embodiments, the CoV S polypeptide comprises one or more modifications selected from K973P, V974P, an inactivated furin cleavage site having an amino acid sequence of QQAQ (SEQ ID NO:7), a deletion of amino acids 229-231, L5F, D67A, D202G, K404N, E471K, N488Y, D601G, and A688V, where the amino acids are numbered relative to a CoV S polypeptide having the amino acid sequence of SEQ ID NO:2. In embodiments, a CoV S polypeptide having one or more modifications selected from K973P, V974P, an inactivated furin cleavage site having an amino acid sequence of QQAQ (SEQ ID NO:7), a deletion of amino acids 229-231, L5F, D67A, D202G, K404N, E471K, N488Y, D601G, and A688V, where the amino acids are numbered relative to a CoV S polypeptide having the amino acid sequence of SEQ ID NO:2, comprises the amino acid sequence of SEQ ID NO:144. In embodiments, a CoV S polypeptide having the amino acid sequence of SEQ ID NO:144 is encoded by a nucleic acid having the sequence of SEQ ID NO:145.

[0149] In embodiments, the CoV S polypeptide comprises one or more modifications selected from K973P, V974P, an inactivated furin cleavage site having an amino acid sequence of GG, a deletion of amino acids 229-231, L5F, D67A, D202G, K404N, E471K, N488Y, D601G, and A688V, where the amino acids are numbered relative to a CoV S polypeptide having a sequence of SEQ ID NO: 2. In embodiments, the CoV S polypeptide comprises one or more modifications selected from K973P, V974P, an inactivated furin cleavage site having an amino acid sequence of GG, a deletion of amino acids 229-231, L5F, D67A, D202G, K404N, E471K, N488Y, D601G, and A688V, where the amino acids are numbered relative to a CoV S polypeptide having a sequence of SEQ ID NO: 2, and comprises the amino acid sequence of SEQ ID NO: 144. In embodiments, the CoV S polypeptide having the amino acid sequence of SEQ ID NO:144 is encoded by a nucleic acid having the sequence of SEQ ID NO:145.

[0150] In embodiments, the CoV S polypeptide comprises one or more modifications selected from K973P, V974P, an inactivated furin cleavage site, L5F, T7N, P13S, D125Y, R177S, K404T, E471K, N488Y, D601G, H642Y, T1014I, and V1163F, where the amino acids are numbered relative to a CoV S polypeptide having the amino acid sequence of SEQ ID NO:2. In embodiments, a CoV S polypeptide comprising one or more modifications selected from K973P, V974P, an inactivated furin cleavage site, L5F, T7N, P13S, D125Y, R177S, K404T, E471K, N488Y, D601G, H642Y, T1014I, and V1163F, where the amino acids are numbered relative to a CoV S polypeptide having the amino acid sequence of SEQ ID NO: 2, has the amino acid sequence of SEQ ID NO: 151. In embodiments, a CoV S polypeptide having the amino acid sequence of SEQ ID NO: 151 is encoded by a nucleic acid having the sequence of SEQ ID NO: 150.

[0151] In embodiments, the CoV S polypeptide comprises one or more modifications selected from K973P, V974P, an inactivated furin cleavage site, a deletion of amino acids 229-231, L5F, D67A, D202G, L229H, K404N, E471K, N488Y, D601G, and A688V, where the amino acids are numbered relative to a CoV S polypeptide having the sequence of SEQ ID NO:2.

[0152] In embodiments, the CoV S polypeptide comprises one or more modifications selected from K973P, V974P, an inactivated furin cleavage site, K404N, E471K, N488Y, L5F, D67A, D202G, L229H, D601G, A688V, and a deletion of amino acids 229-231, where the amino acids are numbered relative to a CoV S polypeptide having the sequence of SEQ ID NO: 2. In embodiments, the inactivated furin cleavage site has an amino acid sequence of QQAQ (SEQ ID NO: 7). In embodiments, the inactivated furin cleavage site has an amino acid sequence of GG.

[0153] In embodiments, the CoV S polypeptide comprises one or more modifications selected from K973P, V974P, an inactivated furin cleavage site, K404N, E471K, and N488K, where the amino acids are numbered relative to a CoV S polypeptide having the amino acid sequence of SEQ ID NO: 2. In embodiments, the CoV S polypeptide comprises one or more modifications selected from K973P, V974P, an inactivated furin cleavage site, K404N, E471K, and N488K. In embodiments, the CoV S polypeptide is the RBD of a CoV S polypeptide having one or more modifications selected from K973P, V974P, an inactivated furin cleavage site, K404N, E471K, and N488K, where the amino acids are numbered relative to a CoV S polypeptide having the amino acid sequence of SEQ ID NO: 2. In embodiments, the CoV S polypeptide is the RBD of a CoV S polypeptide having one or more modifications selected from K973P, V974P, an inactivated furin cleavage site, K404N, E471K, and N488K, and wherein the amino acids are numbered relative to a CoV S polypeptide having the amino acid sequence of SEQ ID NO:2.

[0154] In embodiments, the CoV S polypeptide comprises one or more modifications selected from K973P, V974P, an inactivated furin cleavage site having an amino acid sequence of GG, D601G, E404N, E471K, and N488Y. In embodiments, the CoV S polypeptide comprises one or more modifications selected from K973P, V974P, an inactivated furin cleavage site having an amino acid sequence of GG, and a D601G mutation, where the amino acids are numbered relative to a CoV S polypeptide having the amino acid sequence of SEQ ID NO: 2. In embodiments, the CoV S polypeptide comprises modifications selected from K973P, V974P, an inactivated furin cleavage site having an amino acid sequence of GG, and a D601G mutation, has the amino acid sequence of SEQ ID NO: 133.

[0155] In embodiments, the CoV S polypeptide comprises one or more modifications selected from K973P, V974P, an inactivated furin cleavage site (optionally, the inactivated furin cleavage site is QQAQ (SEQ ID NO: 7) or GG), K404N, E471K, N488K, D67A, D202G, L229H, D601G, and A688V, where the amino acids are numbered relative to a CoV S polypeptide having the amino acid sequence of SEQ ID NO: 2. In embodiments, the CoV S polypeptide comprises one or more modifications selected from K973P, V974P, an inactivated furin cleavage site (optionally, the inactivated furin cleavage site is QQAQ (SEQ ID NO: 7) or GG), K404N, E471K, N488K, D67A, D202G, L229H, D601G, and A688V, where the amino acids are numbered relative to a CoV S polypeptide having the amino acid sequence of SEQ ID NO: 132 or SEQ ID NO: 141. In embodiments, a CoV S polypeptide having the amino acid sequence of SEQ ID NO: 132 is encoded by a nucleic acid having the sequence of SEQ ID NO: 131. In embodiments, a CoV S polypeptide having the amino acid sequence of SEQ ID NO: 132 is encoded by a nucleic acid having the sequence of SEQ ID NO: 142.

[0156] In embodiments, the CoV S polypeptide comprises one or more modifications selected from K973P, V974P, an inactivated furin cleavage site, W139C, and L439R, and the amino acids are numbered relative to a CoV S polypeptide having the amino acid sequence of SEQ ID NO: 2. In embodiments, the CoV S polypeptide comprises the K973P, V974P, an inactivated furin cleavage site, W139C, and L439R modifications, and is expressed with a signal peptide having the amino acid sequence of SEQ ID NO: 117 or SEQ ID NO: 5. In embodiments, the CoV S polypeptide comprises one or more modifications selected from K973P, V974P, an inactivated furin cleavage site, D601G, W139C, and L439R, and the amino acids are numbered relative to a CoV S polypeptide having the amino acid sequence of SEQ ID NO: 2. In embodiments, the CoV S polypeptide contains the modifications K973P, V974P, an inactivated furin cleavage site, D601G, W139C, and L439R and is expressed with a signal peptide having the amino acid sequence of SEQ ID NO:117 or SEQ ID NO:5.

[0157] In embodiments, the CoV S polypeptide comprises one or more modifications selected from K973P, V974P, an inactivated furin cleavage site, D601G, L5F, D67A, D202G, a deletion of amino acids 229-231, R233I, K404N, E471K, N488Y, and A688V, where the amino acids are numbered relative to a CoV S polypeptide having the sequence of SEQ ID NO:2.

[0158] In embodiments, the CoV S polypeptide comprises one or more modifications selected from K973P, V974P, an inactivated furin cleavage site (optionally, the inactivated furin cleavage site is QQAQ (SEQ ID NO: 7)), W139C, S481P, D601G, and L439R, where the amino acids are numbered relative to the CoV S polypeptide having the amino acid sequence of SEQ ID NO: 2. In embodiments, the CoV S polypeptide comprises one or more modifications selected from K973P, V974P, an inactivated furin cleavage site (optionally, the inactivated furin cleavage site is QQAQ (SEQ ID NO: 7)), W139C, D601G, and L439R, where the amino acids are numbered relative to the CoV S polypeptide having the amino acid sequence of SEQ ID NO: 2. In embodiments, the CoV S polypeptide comprises one or more modifications selected from K973P, V974P, an inactivated furin cleavage site (optionally, the inactivated furin cleavage site is QQAQ (SEQ ID NO: 7)), W139C, S481P, and D601G, where the amino acids are numbered relative to a CoV S polypeptide having the amino acid sequence of SEQ ID NO: 2. In embodiments, the CoV S polypeptide comprises one or more modifications selected from K973P, V974P, an inactivated furin cleavage site (optionally, the inactivated furin cleavage site is QQAQ (SEQ ID NO: 7)), W139C, S481P, D601G, and L439R, has an amino acid sequence of SEQ ID NO: 153. In embodiments, the CoV S polypeptide having the amino acid sequence of SEQ ID NO: 153 comprises a signal peptide having the amino acid sequence of SEQ ID NO: 117. In embodiments, the CoV S polypeptide having the amino acid sequence of SEQ ID NO: 153 comprises a signal peptide having the amino acid sequence of SEQ ID NO: 5.

[0159] In embodiments, the CoV S polypeptide comprises one or more modifications selected from K973P, V974P, an inactivated furin cleavage site (optionally, the inactivated furin cleavage site is QQAQ (SEQ ID NO: 7)), T82I, D240G, E471K, D601G, and A688V, where the amino acids are numbered relative to a CoV S polypeptide having the amino acid sequence of SEQ ID NO: 2. In embodiments, the CoV S polypeptide comprises one or more modifications selected from K973P, V974P, an inactivated furin cleavage site (optionally, the inactivated furin cleavage site is QQAQ (SEQ ID NO: 7)), T82I, D240G, E471K, D601G, and A688V, where the amino acids are numbered relative to a CoV S polypeptide having the amino acid sequence of SEQ ID NO: 2, has the amino acid sequence of SEQ ID NO: 156. In embodiments, the CoV S polypeptide comprises one or more modifications selected from K973P, V974P, an inactivated furin cleavage site (optionally, the inactivated furin cleavage site is QQAQ (SEQ ID NO: 7)), T82I, D240G, E471K, D601G, and A688V, where the amino acids are numbered relative to a CoV S polypeptide having the amino acid sequence of SEQ ID NO: 2, and comprises a signal peptide having the amino acid sequence of SEQ ID NO: 154 or SEQ ID NO: 5.

[0160] In embodiments, the CoV S polypeptide comprises one or more modifications selected from K973P, V974P, an inactivated furin cleavage site (optionally, the inactivated furin cleavage site is QQAQ (SEQ ID NO: 7)), T82I, D240G, S464N, D601G, and A688V, where the amino acids are numbered relative to a CoV S polypeptide having the amino acid sequence of SEQ ID NO: 2. In embodiments, the CoV S polypeptide comprises one or more modifications selected from K973P, V974P, an inactivated furin cleavage site (optionally, the inactivated furin cleavage site is QQAQ (SEQ ID NO: 7)), T82I, D240G, S464N, D601G, and A688V, where the amino acids are numbered relative to a CoV S polypeptide having the amino acid sequence of SEQ ID NO: 2, has the amino acid sequence of SEQ ID NO: 158. In embodiments, the CoV S polypeptide has the amino acid sequence of SEQ ID NO: 154, comprising one or more modifications selected from K973P, V974P, an inactivated furin cleavage site (optionally, the inactivated furin cleavage site is QQAQ (SEQ ID NO: 7)), T82I, D240G, S464N, D601G, and A688V, where the amino acids are numbered relative to the CoV S polypeptide having the amino acid sequence of SEQ ID NO: 2.

[0161] In embodiments, the CoV S polypeptide comprises one or more modifications selected from K973P, V974P, an inactivated furin cleavage site (optionally, the inactivated furin cleavage site is QQAQ (SEQ ID NO: 7)), a deletion of amino acid 56, a deletion of amino acid 57, a deletion of amino acid 131, an N488Y mutation, an A557D mutation, a D601G mutation, a P668H mutation, a T703I mutation, an S969A mutation, and a D1105H mutation, and the CoV S polypeptide is numbered relative to a wild-type SARS-CoV-2 S polypeptide having the amino acid sequence of SEQ ID NO: 2. In embodiments, the CoV S polypeptide comprises one or more modifications selected from K973P, V974P, an inactivated furin cleavage site (optionally, the inactivated furin cleavage site is QQAQ (SEQ ID NO: 7)), a deletion of amino acid 56, a deletion of amino acid 57, a deletion of amino acid 132, an N488Y mutation, an A557D mutation, a D601G mutation, a P668H mutation, a T703I mutation, an S969A mutation, and a D1105H mutation, and the CoV S polypeptide is numbered relative to a wild-type SARS-CoV-2 S polypeptide having the amino acid sequence of SEQ ID NO: 2.

[0162] In embodiments, the CoV S polypeptide comprises one or more modifications selected from K973P, V974P, an inactivated furin cleavage site (optionally, the inactivated furin cleavage site is QQAQ (SEQ ID NO: 7)), a D67A mutation, a L229H mutation, a R233I mutation, an A688V mutation, a N488Y mutation, a K404N mutation, an E471K mutation, and a D601G mutation, and the CoV S polypeptide is numbered relative to a wild-type SARS-CoV-2 S polypeptide having the amino acid sequence of SEQ ID NO: 2.

[0163] In embodiments, the CoV S polypeptide comprises one or more modifications selected from K973P, V974P, an inactivated furin cleavage site (optionally, the inactivated furin cleavage site is QQAQ (SEQ ID NO: 7)), an L5F mutation, a T7N mutation, a P13S mutation, a D125Y mutation, an R177S mutation, a K404T mutation, an E471K mutation, an N488Y mutation, a D601G mutation, an H642Y mutation, a T1014I mutation, and a T1163F mutation, and the CoV S polypeptide is numbered relative to a wild-type SARS-CoV-2 S polypeptide having the amino acid sequence of SEQ ID NO: 2.

[0164] In embodiments, the CoV S polypeptide comprises one or more modifications selected from K986P, V987P, an inactivated furin cleavage site (optionally, the inactivated furin cleavage site is QQAQ (SEQ ID NO: 7)), an S13I mutation, a W152C mutation, and an L452R mutation, and the CoV S polypeptide is numbered relative to wild-type SARS-CoV-2 S having the amino acid sequence of SEQ ID NO: 1. In embodiments, the CoV S polypeptide comprises one or more modifications selected from K986P, V987P, an inactivated furin cleavage site (optionally, the inactivated furin cleavage site is QQAQ (SEQ ID NO: 7)), an S13I mutation, a W152C mutation, and an L452R mutation, and the CoV S polypeptide is numbered relative to wild-type SARS-CoV-2 S having the amino acid sequence of SEQ ID NO: 1, and lacks an N-terminal signal peptide.

[0165] In embodiments, the CoV spike (S) polypeptide comprises a polypeptide linker. In embodiments, the polypeptide linker comprises glycine and serine. In embodiments, the linker has about 50%, about 55%, about 60%, about 65%, about 70%, about 75%, about 80%, about 85%, about 90%, about 95%, or about 100% glycine.

[0166] In embodiments, the polypeptide linker is (SGGG) n(SEQ ID NO:91), where n is an integer from 1 to 50 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, or 50). In an embodiment, the polypeptide linker has an amino acid sequence corresponding to SEQ ID NO:90.

[0167] In embodiments, the polypeptide linker is (GGGGS) n (having repeats of SEQ ID NO:93, where n is an integer from 1 to 50 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, or 50).

[0168] In embodiments, the polypeptide linker is (GGGS) n (Having repeats of SEQ ID NO:92, where n is an integer of 1 to 50 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, or 50).

[0169] In some aspects, the polypeptide linker is a poly-(Gly)n linker, where n is 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 16, 17, 18, 19, or 20. In other embodiments, the linker is selected from the group consisting of a dipeptide, a tripeptide, and a quadripeptide. In embodiments, the linker is a dipeptide selected from the group consisting of alanine-serine (AS), leucine-glutamic acid (LE), and serine-arginine (SR).

[0170] In embodiments, the polypeptide linker comprises 1-100 contiguous amino acids of a naturally occurring CoV S polypeptide or a CoV S polypeptide disclosed herein. In embodiments, the polypeptide linker has an amino acid sequence corresponding to SEQ ID NO:94.

[0171] In an embodiment, the CoV spike (S) polypeptide comprises a Foldon. In an embodiment, TMCT is replaced by Foldon. In an embodiment, Foldon trimers the CoV spike (S) polypeptide. In an embodiment, Foldon is an amino acid sequence known in the art. In an embodiment, Foldon has the amino acid sequence of SEQ ID NO: 68. In an embodiment, Foldon is a T4 fibritin trimerization motif. In an embodiment, the T4 fibritin trimerization domain has the amino acid sequence of SEQ ID NO: 103. In an embodiment, Foldon is separated in amino acid sequence from the CoV spike (S) polypeptide by a polypeptide linker. Non-limiting examples of polypeptide linkers are found throughout this disclosure.

[0172] In embodiments, the present disclosure provides CoV S polypeptides and nanoparticles comprising fragments of coronavirus S proteins, and vaccines comprising same. In embodiments, the fragment of a coronavirus S protein is about 10 to about 1500 amino acids in length (e.g., about 10, about 20, about 30, about 40, about 50, about 60, about 70, about 80, about 90, about 100, about 150, about 200, about 250, about 300, about 350, about 400, about 450, about 500, about 550, about 600, about 650, about 700, about 750, about 800, about 850, about 900, about 950, about 1000, about 1050, about 1100, about 1150, about 1200, about 1250, about 1300, about 1350, about 1400, about 1450, or about 1500 amino acids in length). In embodiments, the fragment of a coronavirus S protein is selected from the group consisting of a receptor binding domain (RBD), subdomain 1, subdomain 2, upper helix, fusion peptide, binding region, amino acid repeat 1, central helix, amino acid repeat 2, NTD, and TMCT.

[0173] In embodiments, the CoV S polypeptide comprises an RBD and subdomain 1. In embodiments, the CoV S polypeptide comprising an RBD and subdomain 1 is amino acids 319-591 of SEQ ID NO:1.

[0174] In embodiments, the CoV S polypeptide comprises a fragment of a coronavirus S protein, and the fragment of the coronavirus S protein is an RBD. Non-limiting examples of RBDs include the RBD of SARS-CoV-2 (amino acid sequence=SEQ ID NO:69), the RBD of SARS (amino acid sequence=SEQ ID NO:70), and the RBD of MERS (amino acid sequence=SEQ ID NO:71).

[0175] In embodiments, the CoV S polypeptide comprises two or more RBDs connected by a polypeptide linker. In embodiments, the polypeptide linker has the amino acid sequence of SEQ ID NO:90 or SEQ ID NO:94.

[0176] In some embodiments, the CoV S polypeptide comprises 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 RBDs.

[0177] In some embodiments, the CoV S polypeptide comprises two or more SARS-CoV-2 RBDs connected by a polypeptide linker. In embodiments, the antigen comprising two or more SARS-CoV-2 RBDs has an amino acid sequence corresponding to one of SEQ ID NOs: 72-75.

[0178] In embodiments, the CoV S polypeptide comprises a SARS-CoV-2 RBD and a SARS RBD. In embodiments, the CoV S polypeptide comprises a SARS-CoV-2 RBD and a SARS RBD, each RBD being separated by a polypeptide linker. In embodiments, the CoV S polypeptide comprising a SARS-CoV-2 RBD and a SARS RBD has an amino acid sequence selected from the group consisting of SEQ ID NOs: 76-79.

[0179] In embodiments, the CoV S polypeptide comprises a SARS-CoV-2 RBD and a MERS RBD. In embodiments, the CoV S polypeptide comprises a SARS-CoV-2 RBD and a MERS RBD, each RBD being separated by a polypeptide linker.

[0180] In embodiments, the CoV S polypeptide comprises a SARS RBD and a MERS RBD. In embodiments, the CoV S polypeptide comprises a SARS RBD and a MERS RBD, each RBD being separated by a polypeptide linker.

[0181] In embodiments, the CoV S polypeptide comprises a SARS-CoV-2 RBD, a SARS RBD, and a MERS RBD. In embodiments, the CoV S polypeptide comprises a SARS-CoV-2 RBD, a SARS RBD, and a MERS RBD, each RBD being separated by a polypeptide linker. In embodiments, the CoV S polypeptide comprising a SARS-CoV-2 RBD, a SARS RBD, and a SARS RBD has an amino acid sequence selected from the group consisting of SEQ ID NOs: 80-83.

[0182] In embodiments, the CoV S polypeptides described herein are expressed with an N-terminal signal peptide. In embodiments, the N-terminal signal peptide has the amino acid sequence of SEQ ID NO: 5 (MFVFLVLLPLVSS). In embodiments, the N-terminal signal peptide has the amino acid sequence of SEQ ID NO: 117 (MFVFLVLLPLVSI). In embodiments, the N-terminal signal peptide has the amino acid sequence of SEQ ID NO: 154 (MFVFFVLLPLVSS). In embodiments, the signal peptide may be replaced with any signal peptide that allows expression of the CoVS protein. In embodiments, one or more of the CoV S protein signal peptide amino acids may be deleted or mutated. The initial methionine residue is maintained to initiate expression. In embodiments, the CoV S polypeptide is encoded by a nucleic acid sequence selected from the group consisting of SEQ ID NO:35, SEQ ID NO:37, SEQ ID NO:95, SEQ ID NO:43, SEQ ID NO:47, SEQ ID NO:50, SEQ ID NO:53, SEQ ID NO:55, SEQ ID NO:57, SEQ ID NO:96, SEQ ID NO:60, SEQ ID NO:131, SEQ ID NO:135, SEQ ID NO:142, SEQ ID NO:145, SEQ ID NO:148, and SEQ ID NO:150. In embodiments, the N-terminal signal peptide of the CoV S polypeptide comprises a mutation at Ser-13 compared to the native CoV spike (S) signal polypeptide (SEQ ID NO:5). In embodiments, Ser-13 is mutated to any native amino acid. In embodiments, Ser-13 is mutated to alanine, methionine, isoleucine, leucine, threonine, or valine. In embodiments, Ser-13 is mutated to isoleucine.

[0183] Following expression of the CoV S protein in the host cell, the N-terminal signal peptide is cleaved to provide the mature CoV protein sequence (SEQ ID NOs: 2, 4, 38, 41, 44, 48, 51, 54, 58, 61, 63, 65, 67, 73, 75, 78, 79, 82, 83, 85, 87, 89, 106, 110, 132, 133, 114, 138, 141, 144, 147, 151, 153, 156, and 158). In embodiments, the signal peptide is cleaved by a host cell protease. In aspects, the full-length protein can be isolated from the host cell, following cleavage of the signal peptide.

[0184] During expression and purification, a signal peptide from a CoV spike (S) polypeptide having an amino acid sequence corresponding to SEQ ID NOs: 1, 3, 36, 40, 42, 46, 49, 52, 56, 59, 62, 64, 66, 72, 74, 76, 77, 80, 81, 84, 86, 87, 105, 107, 88, 109, 130, 134, 136, 137, 140, 143, 146, 149, 152, 155, 157, 159-163 was synthesized. After cleavage of the peptides, a mature polypeptide having an amino acid sequence selected from the group consisting of SEQ ID NOs: 2, 4, 38, 41, 44, 48, 51, 54, 58, 61, 63, 65, 67, 73, 75, 78, 79, 82, 83, 85, 106, 108, 89, and 110, 112-115, 132, 133, 114, 138, 141, 144, 147, 151, 153, 156, 158, 164-168 is obtained and used to produce a CoV S nanoparticle vaccine or CoV S nanoparticles.

[0185] Advantageously, the disclosed CoV S polypeptides can have enhanced protein expression and stability relative to the native CoV spike (S) protein.

[0186] In embodiments, the CoV S polypeptides described herein include further modifications from the native coronavirus S protein (SEQ ID NO:2). In embodiments, the coronavirus S proteins described herein exhibit at least 80%, or at least 90%, or at least 95%, or at least 97%, or at least 99% identity to the native coronavirus S protein. Those skilled in the art use known techniques to calculate the percent identity of a recombinant coronavirus S protein to a native protein or any CoV polypeptide described herein. For example, the percent identity can be calculated using the tools CLUSTALW2 or Basic Local Alignment Search Tool (BLAST), available online. For CLUSTALW2 pairwise alignment, the following default parameters can be used: protein weight matrix=Gonnet; gap opening=10; gap widening=0.1.

[0187] In embodiments, the amino acid sequence of a CoV S polypeptide described herein is at least 91%, at least 92%, at least 93%, at least 94%, 95%, at least 96%, at least 97%, at least 98%, at least 99%, at least 99.5% identical, or 100% identical to a CoV S polypeptide having the amino acid sequence of SEQ ID NO: 87. The CoV S polypeptide may have up to about 1, up to about 2, up to about 3, up to about 4, up to about 5, up to about 10, up to about 15, up to about 20, up to about 25, up to about 30, up to about 35, up to about 40, up to about 45, or up to 50 amino acid deletions, insertions, or mutations compared to the amino acid sequence of a CoV S polypeptide having the amino acid sequence of SEQ ID NO: 87. The CoV S polypeptide may have a deletion, insertion, or mutation of about 1 to about 5 amino acids, about 3 to about 10 amino acids, about 5 to 10 amino acids, about 8 to 12 amino acids, about 10 to 15 amino acids, about 12 to 17 amino acids, about 15 to 20 amino acids, about 18 to 23 amino acids, about 20 to 25 amino acids, about 22 to about 27 amino acids, about 25 to 30 amino acids, about 30 to 35 amino acids, about 35 to 40 amino acids, about 40 to 45 amino acids, or about 45 to 50 amino acids, compared to a CoV S polypeptide having the amino acid sequence of SEQ ID NO:87. In some embodiments, the CoV S polypeptides described herein contain about 1, about 2, about 3, about 4, about 5, about 6, about 7, about 8, about 9, about 10, about 11, about 12, about 13, about 14, about 15, about 16, about 17, about 18, about 19, about 20, about 21, about 22, about 23, about 24, or about 25 substitutions compared to the coronavirus S protein (SEQ ID NO:87).

[0188] In embodiments, a CoV S polypeptide described herein is at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or at least 99.5% identical to a CoV S polypeptide having an amino acid sequence selected from any one of SEQ ID NOs: 2, 4, 38, 41, 44, 48, 51, 54, 58, 61, 63, 65, 67, 73, 75, 78, 79, 82, 83, 85, 106, 108, 89, and 110, 112-115, 132, 133, 114, 138, 141, 144, 147, 151, 153, 156, and 158, 164-168.

[0189] In embodiments, the coronavirus S polypeptide is extended at the N-terminus, C-terminus, or both N-terminus and C-terminus. In aspects, the extension is a tag useful for functions such as purification or detection. In aspects, the tag comprises an epitope. For example, the tag can be a polyglutamate tag, a FLAG tag, an HA tag, a polyHis tag (having about 5-10 histidines) (SEQ ID NO: 101), a hexahistidine tag (SEQ ID NO: 100), an 8xHis tag (having 8 histidines) (SEQ ID NO: 102), a Myc tag, a glutathione-S-transferase tag, a green fluorescent protein tag, a maltose binding protein tag, a thioredoxin tag, or an Fc tag. In other aspects, the extension can be an N-terminal signal peptide fused to the protein to enhance expression. Although such signal peptides are often cleaved during expression in cells, some nanoparticles can contain antigens with the signal peptide intact. Thus, when the nanoparticle comprises an antigen, the antigen may comprise an extension and thus may be a fusion protein when incorporated into the nanoparticle. For purposes of calculating identity to the sequence, the extension is not included. In an embodiment, the tag is a protease cleavage site. Non-limiting examples of protease cleavage sites include HRV3C protease cleavage site, chymotrypsin, trypsin, elastase, endopeptidase, caspase-1, caspase-2, caspase-3, caspase-4, caspase-5, caspase-6, caspase-7, caspase-8, caspase-9, caspase-10, enterokinase, factor Xa, granzyme B, TEV protease, and thrombin. In an embodiment, the protease cleavage site is an HRV3C protease cleavage site. In an embodiment, the protease cleavage site comprises the amino acid sequence of SEQ ID NO:98.

[0190] In embodiments, the CoV S glycoprotein comprises a fusion protein. In embodiments, the CoV S glycoprotein comprises an N-terminal fusion protein. In embodiments, the CoV S glycoprotein comprises a C-terminal fusion protein. In embodiments, the fusion protein includes a tag useful for expression, purification, or detection of the protein. In embodiments, the tag is a polyHis tag (having about 5-10 histidines), a Myc tag, a glutathione-S-transferase tag, a green fluorescent protein tag, a maltose binding protein tag, a thioredoxin tag, a Strep tag, a twin-Strep tag, or an Fc tag. In embodiments, the tag is an Fc tag. In embodiments, the Fc tag is a monomer, dimer, or trimer. In embodiments, the tag is a hexahistidine tag, such as a polyHis tag containing six histidines (SEQ ID NO: 100). In embodiments, the tag is a twin-Strep tag having the amino acid sequence of SEQ ID NO: 99.

[0191] In embodiments, the CoV S polypeptide is a fusion protein that includes another coronavirus protein. In embodiments, the other coronavirus protein is from the same coronavirus. In embodiments, the other coronavirus protein is from another coronavirus.

[0192] In embodiments, the CoV S protein may be truncated. For example, the N-terminus may be truncated by about 10 amino acids, about 30 amino acids, about 50 amino acids, about 75 amino acids, about 100 amino acids, or about 200 amino acids. The C-terminus may be truncated instead of or in addition to the N-terminus. For example, the C-terminus may be truncated by about 10 amino acids, about 30 amino acids, about 50 amino acids, about 75 amino acids, about 100 amino acids, or about 200 amino acids. To calculate the identity to a protein with a truncation, the identity is measured for the remainder of the protein.

[0193] Detergent-core nanoparticles containing CoV spike (S) polypeptide In embodiments, the compositions disclosed herein comprise detergent-core nanoparticles comprising a CoV S polypeptide associated with a detergent core.

[0194] In an embodiment, the nanoparticles of the present disclosure comprise a mature CoV S polypeptide. In an embodiment, the nanoparticles of the present disclosure comprise a CoV S polypeptide associated with a detergent core. The presence of the detergent facilitates the formation of the nanoparticle by forming a core that assembles and presents the antigen. In an embodiment, the nanoparticles may comprise a CoV S polypeptide incorporated into a multi-oligomeric glycoprotein-detergent (e.g., PS80) nanoparticle in which the head regions protrude outward and hydrophobic regions, and the PS80 detergent forms a central core surrounded by glycoproteins. In an embodiment, the CoV S polypeptide essentially comprises or is adapted to comprise a transmembrane domain to facilitate association of the protein to the detergent core. In an embodiment, the CoV S polypeptide comprises a head domain. Primarily, the transmembrane domain of the CoV S polypeptide trimer associates with the detergent, although other portions of the polypeptide may also interact. Advantageously, the nanoparticles have improved resistance to environmental stresses, resulting in enhanced stability and / or improved presentation to the immune system due to the organization of multiple copies of the protein around the detergent.

[0195] In embodiments, the detergent core is a non-ionic detergent core. In embodiments, the CoV S polypeptide is associated with the non-ionic detergent core. In embodiments, the detergent is selected from the group consisting of polysorbate-20 (PS20), polysorbate-40 (PS40), polysorbate-60 (PS60), polysorbate-65 (PS65), and polysorbate-80 (PS80). In embodiments, the detergent is PS80.

[0196] In embodiments, the CoV S polypeptide forms trimers. In embodiments, the CoV S polypeptide nanoparticles are comprised of multiple polypeptide trimers surrounding a non-ionic detergent core. In embodiments, the nanoparticles comprise at least about one trimer or more. In embodiments, the nanoparticles comprise at least about 5 trimers to about 30 trimers of the spike protein. In embodiments, each nanoparticle may comprise 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, or 15, 20, 25, or 30 trimers (including all values ​​and ranges therebetween). The compositions disclosed herein may comprise nanoparticles having different numbers of trimers. For example, the compositions may comprise nanoparticles in which the number of trimers ranges from 2 to 9, and in embodiments, the nanoparticles in the composition may comprise 2 to 6 trimers. In embodiments, the compositions comprise a heterogeneous population of nanoparticles having 2 to 6 trimers per nanoparticle, or 2 to 9 trimers per nanoparticle. In embodiments, the compositions may comprise a substantially homogeneous population of nanoparticles. For example, the population can contain about 95% nanoparticles having 5 trimers.

[0197] The nanoparticles disclosed herein are in a range of particle sizes. In embodiments, the nanoparticles disclosed herein are in a range of Z-ave size to particle size from about 20 nm to about 60 nm, about 20 nm to about 50 nm, about 20 nm to about 45 nm, about 20 nm to about 35 nm, about 20 nm to about 30 nm, about 25 nm to about 35 nm, or about 25 nm to about 45 nm. Particle size (Z-ave) is measured by dynamic light scattering (DLS) using a Zetasizer NanoZS (Malvern, UK) unless otherwise specified.

[0198] In embodiments, nanoparticles comprising a CoV S polypeptide disclosed herein have a reduced particle size compared to nanoparticles comprising a wild-type CoV S polypeptide, in embodiments, the CoV S polypeptide is at least about 40% smaller in size, e.g., at least about 40%, at least about 45%, at least about 50%, at least about 55%, at least about 60%, at least about 65%, at least about 70%, at least about 75%, at least about 80%, or at least about 85% smaller in size.

[0199] Nanoparticles comprising CoV S polypeptides disclosed herein are more uniform in size, shape, and weight than nanoparticles comprising wild-type CoV S polypeptides. Polydispersity index (PDI), a measure of heterogeneity, is measured by dynamic light scattering using a Malvern Scaler unless otherwise specified. In embodiments, the particles measured herein have a PDI of about 0.2 to about 0.45, e.g., about 0.2, about 0.25, about 0.29, about 0.3, about 0.35, about 0.40, or about 0.45. In embodiments, the nanoparticles measured herein have a PDI that is at least about 25% less than the PDI of nanoparticles comprising wild-type CoV S polypeptides, e.g., at least about 25%, at least about 30%, at least about 35%, at least about 40%, at least about 45%, at least about 50%, at least about 55%, or at least about 60% less.

[0200] The CoV S polypeptides and nanoparticles comprising same have improved thermal stability compared to wild-type CoV S polypeptides or nanoparticles thereof. Thermal stability of CoV S polypeptides is measured using differential scanning calorimetry (DSC) unless otherwise specified. Transition enthalpy (ΔΗcal) is the energy required to unfold a CoV S polypeptide. In embodiments, the CoV S polypeptide has an increased ΔΗcal compared to a wild-type CoV S polypeptide. In embodiments, the ΔΗcal of the CoV S polypeptide is about 2-fold, about 3-fold, about 4-fold, about 5-fold, about 6-fold, about 7-fold, about 8-fold, about 9-fold, or about 10-fold greater than the ΔΗcal of the wild-type CoV S polypeptide.

[0201] Several nanoparticle types can be included in the vaccine compositions disclosed herein. In an embodiment, the nanoparticle types are in the form of anisotropic rods, which can be dimeric or monomeric. In another embodiment, the nanoparticle types are spherical oligomers. In yet another embodiment, the nanoparticles can be described as intermediate nanoparticles with intermediate sedimentation properties between the first two types. The formation of nanoparticle types can be controlled by controlling detergent and protein concentrations during the manufacturing process. The nanoparticle types can be determined by measuring the sedimentation coefficient.

[0202] (ii) at least three HA glycoproteins In an embodiment, the immunogenic composition of the present disclosure comprises at least three HA glycoproteins or at least four HA glycoproteins. In an embodiment, the immunogenic composition of the present disclosure comprises three or four HA glycoproteins. In an embodiment, each of the HA glycoproteins is from a different influenza strain. In an embodiment, three HA glycoproteins are from an influenza A strain and one HA glycoprotein is from an influenza B strain. In an embodiment, two HA glycoproteins are from an influenza A strain and two HA glycoproteins are from an influenza B strain. In an embodiment, two HA glycoproteins are from an influenza A strain and one HA glycoprotein is from an influenza B strain.

[0203] In embodiments, each of the at least three HA glycoproteins is separately isolated using an egg-based production process that includes (a) growing influenza virus in eggs and (b) harvesting the influenza virus.

[0204] In embodiments, the influenza virus is a live virus. In embodiments, the influenza virus is a weakened or "attenuated" virus. In embodiments, the influenza virus is optimized for growth in eggs. In embodiments, the optimized influenza virus lacks the polybasic cleavage site of hemagglutinin. The following papers provide a detailed description of the development of optimized influenza viruses (referred to as "candidate vaccine viruses") and are incorporated herein by reference in their entirety: Belser et al. Virology. 2017 Nov;511:135-141.

[0205] In embodiments, the egg is a chicken egg. In embodiments, the chicken egg is an embryonated chicken egg. In embodiments, the egg is a pathogen-free egg. In embodiments, the influenza virus is propagated by inoculation into the allantoic cavity of an embryonated chicken egg. The following papers describe exemplary inoculation methods and are incorporated herein by reference in their entirety: Brauer et al. J Vis Exp. 2015;(97):52421

[0206] In embodiments, the egg-based manufacturing process includes purifying influenza virus. In embodiments, the influenza virus is purified using any of the following techniques: centrifugation, chromatography, precipitation, or nanofiltration. In embodiments, the centrifugation technique is ultracentrifugation. In embodiments, the virus is purified using zonal centrifugation. In embodiments, the zonal centrifugation is continuous-flow zonal centrifugation.

[0207] In embodiments, the egg-based manufacturing process includes inactivating (also referred to herein as "killing") the influenza virus. In embodiments, the influenza virus is inactivated using low pH (e.g., a pH of about 3.5 to 5.5), heat, ethanol, ultraviolet light, exposure to detergents (e.g., octylphenol), or exposure to chemicals (e.g., 2-propanol, ethanol, iodopovidone). In embodiments, the purified virus is inactivated by ultraviolet light, betapropiolactone, sodium deoxycholate, formaldehyde, or any combination thereof.

[0208] In an embodiment, the egg-based manufacturing process includes exposing influenza virus to a detergent. The detergent can be sodium taurodeoxycholate, octylphenol ethoxylate (Triton®-X100), or cetyltrimethylammonium bromide. When influenza virus is exposed to detergent, influenza split virions are formed. In an embodiment, at least three HA glycoproteins are in the form of influenza split virions.

[0209] In embodiments, the egg-based manufacturing process involves purifying influenza antigens (eg, hemagglutinin) from the virus.

[0210] An egg-based manufacturing process is used to manufacture the following Food and Drug Administration (FDA)-approved influenza vaccines: AFLURIA® tetravalent, FLUARIX® tetravalent, FLULAVAL tetravalent, FLUZONE® tetravalent, FLUZONE® High Dose tetravalent, FLUMIST® tetravalent, FLUAD®, and FLUAD® tetravalent.

[0211] In embodiments, each of the at least three HA glycoproteins is isolated using a cell culture-based process. In embodiments, the cell culture-based process comprises (i) growing influenza virus in cells and (ii) harvesting the virus from the cells. In embodiments, the cell culture-based process comprises (i) transfecting cells with a vector comprising a hemagglutinin and (ii) harvesting the hemagglutinin from the cells. In embodiments, the cell culture-based process comprises (i) transducing cells with a virus comprising a hemagglutinin and (ii) harvesting the hemagglutinin from the cells. In embodiments, the harvested hemagglutinin is a recombinant hemagglutinin.

[0212] In embodiments, the cell is an animal cell, a bacterial cell, an insect cell, or a fungal cell. In embodiments, the animal is a human, a bird (e.g., a chicken), a dog, a reptile, a goat, a pig, a mouse, a rabbit, or a rat.

[0213] In embodiments, the hemagglutinin-encoding virus is a baculovirus, a lentivirus, or an adeno-associated virus.

[0214] In embodiments, influenza viruses produced using a cell culture-based process are purified. Any of the purification techniques described for purifying influenza viruses produced using an egg-based manufacturing process can be used to purify influenza viruses produced using a cell culture-based process.

[0215] In embodiments, the hemagglutinin produced using a cell culture-based process is purified. Purification techniques include chromatography, centrifugation, precipitation, and nanofiltration.

[0216] The Food and Drug Administration (FDA)-approved influenza vaccine, FLUCELVAX® quadrivalent, is manufactured using a cell culture-based process.

[0217] In embodiments, each of the at least three HA glycoproteins is a recombinant hemagglutinin. The Food and Drug Administration (FDA) approved influenza vaccine FLUBLOK® quadrivalent is a recombinant hemagglutinin.

[0218] In an embodiment, the at least three hemagglutinins are in the form of recombinant hemagglutinins. The recombinant hemagglutinins are isolated from cells that produce the hemagglutinins. In an embodiment, the cells that produce the hemagglutinins are transfected with a vector that encodes the hemagglutinins. In an embodiment, the cells that produce the hemagglutinins are transduced with a virus that encodes the hemagglutinins.

[0219] (iia) at least three HA glycoprotein-detergent-core nanoparticles containing hemagglutinin; In embodiments, the compositions disclosed herein comprise detergent-core nanoparticles comprising hemagglutinin from influenza virus. The aforementioned detergent-core nanoparticles are described in detail in U.S. Patent No. 10,426,829, which is incorporated herein by reference in its entirety for all purposes.

[0220] The detergent-core nanoparticles comprise hemagglutinin from influenza virus, which is associated with a detergent core. In embodiments, the hemagglutinin is a trimer. Each nanoparticle may comprise 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15 trimers. In embodiments, the nanoparticles comprise about 2 to about 9, about 2 to about 6, or about 5 hemagglutinin trimers. The hemagglutinin is associated with a non-ionic detergent that comprises the core of the nanoparticle. In embodiments, the detergent is selected from polysorbate-20 (PS20), polysorbate-40 (PS40), polysorbate-60 (PS60), polysorbate-65 (PS65), and polysorbate-80 (PS80). The presence of the detergent facilitates the formation of the nanoparticle by forming a core that organizes and presents antigens. In embodiments, the nanoparticles may comprise antigens incorporated into multi-oligomeric glycoprotein-PS80 protein-detergent nanoparticles in which the head regions protrude outward and hydrophobic regions and the PS80 detergent forms a central core surrounded by the antigen.

[0221] The nanoparticles disclosed herein have a Z-ave size in the range of about 20 nm to about 60 nm, about 20 nm to about 50 nm, about 20 nm to about 45 nm, or about 25 nm to about 45 nm.

[0222] In an embodiment, detergent-core nanoparticles are produced in insect cells by expressing HA protein using a baculovirus expression system and extracting the HA protein with detergent. During purification, the first detergent is exchanged for a second detergent, typically a non-ionic detergent, to obtain nanoparticles with a non-ionic detergent core in which the transmembrane domain of the HA protein is embedded in the form of a trimer. Figure 7 (left panel) shows these structures as observed by electron microscopy.

[0223] The hemagglutinin contained in the detergent-core nanoparticles or HaSMaNs described herein can be derived from any influenza virus strain. Human influenza A and B viruses cause seasonal epidemics of disease almost every winter in the United States.

[0224] The HA protein may be selected from subtypes H1, H2, H3, H4, H5, H6, H7, H8, H9, H10, H11, H12, H13, H14, H15, H16, H17, and H18. Phylogenetically, influenza is divided into groups. For HA, group 1 includes H1, H2, H5, H6, H8, H9, H11, H12, H13, H16, H17, and H18, and group 2 includes H3, H4, H7, H10, H14, and H15.

[0225] In embodiments, the detergent-core nanoparticles or HaSMaN are trypsin-resistant nanoparticles produced using neutral pH purification. Trypsin resistance is achieved by the neutral pH range of about 6.9 to 8.5 during purification and preparation of the HA nanoparticles. Trypsin-resistant influenza glycoproteins and trypsin-resistant influenza nanoparticles; and methods for their production are described in detail in U.S. Patent No. 10,426,829.

[0226] In an embodiment, the hemagglutinin of the detergent-core nanoparticle or HaSMaN described herein comprises a full-length wild-type hemagglutinin amino acid sequence. In an embodiment, the hemagglutinin is a hemagglutinin variant. In an embodiment, the hemagglutinin shows at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, at least 98%, or at least 99% identity to the wild-type hemagglutinin protein. The identity percentage can be calculated using the alignment program ClustalW2 available at www.ebi.ac.uk / Tools / msa / clustalw2 / . The following default parameters can be used for pairwise alignment: protein weight matrix=Gonnet; gap open=10; gap extension=0.1.

[0227] HA is a homotrimer with each monomer consisting of about 550 amino acid residues. Each monomer of HA is conceptually divided into three domains: an ectodomain of about 515 residues that constitutes the extraviral portion of the molecule, a single stretch of 27 residues that defines the transmembrane (TM) domain, and about 10 residues that constitute the cytoplasmic tail (CT). Although some modifications may be made to hemagglutinin, the formation of both detergent core nanoparticles and HaSMaN requires an intact transmembrane domain (TM). Thus, in certain embodiments, the modified HA protein sequence contains 100% identity to the wild-type TM and CT domains with some flexibility in the remaining ectodomain portion, where identity may be at least 90% or at least 95%. The domains may be identified by homology to the amino acid sequence of the TM and CT domains of Japan / 305 / 57 HA shown in Figure 1 of Melikyan et al. (Mol Biol Cell. 1999 Jun;10(6):1821-1836), although it should be noted that the boundaries of the ectodomain, TM, and CT domains can vary by up to three amino acids from HA protein to HA protein. (iib) Influenza vaccine - HaSMaN (hemagglutinin saponin matrix nanoparticles)

[0228] In embodiments, the immunogenic and vaccine compositions described herein comprise HaSMaN (hemagglutinin saponin matrix nanoparticles). Figure 7 (right panel) shows the HaSMaN structure as seen by electron microscopy. The HA glycoprotein decorates the matrix cage-like structure. The HaSMaN structure is formed by preparing detergent-corenan particles containing hemagglutinin from influenza virus and then incubating these with ISCOM matrix adjuvant particles for a period of time. ISCOM matrix particles are shown in the center panel of Figure 7. Notably, HaSMaN forms readily with influenza A HA protein, but not with influenza B HA protein.

[0229] The HaSMaN disclosed herein is produced by incubating detergent-core nanoparticles with an ISCOM matrix adjuvant comprising a saponin fraction, cholesterol, and phospholipids. In embodiments, the HaSMaN is formed by incubating detergent-core nanoparticles with the ISCOM matrix adjuvant for about 24 hours to about 48 hours. For example, the detergent-core nanoparticles can be incubated with the ISCOM matrix adjuvant for about 24 hours, about 25 hours, about 26 hours, about 27 hours, about 28 hours, about 29 hours, about 30 hours, about 31 hours, about 32 hours, about 33 hours, about 34 hours, about 35 hours, about 36 hours, about 37 hours, about 38 hours, about 39 hours, about 40 hours, about 41 hours, about 42 hours, about 43 hours, about 44 hours, about 45 hours, about 46 hours, about 47 hours, about 48 hours, or more. In some embodiments, HaSMaN is formed by incubating detergent-core nanoparticles with an ISCOM matrix adjuvant for at least about 24 hours, at least about 25 hours, at least about 26 hours, at least about 27 hours, at least about 28 hours, at least about 29 hours, at least about 30 hours, at least about 31 hours, at least about 32 hours, at least about 33 hours, at least about 34 hours, at least about 35 hours, at least about 36 hours, at least about 37 hours, at least about 38 hours, at least about 39 hours, at least about 40 hours, at least about 41 hours, at least about 42 hours, at least about 43 hours, at least about 44 hours, at least about 45 hours, at least about 46 hours, at least about 47 hours, or at least about 48 hours. In embodiments, HaSMaN is formed by incubating detergent-core nanoparticles with an ISCOM matrix adjuvant at a temperature of about 4° C. to about 25° C. For example, HaSMaN can be formed by incubating with ISCOM matrix adjuvant at a temperature of about 4°C, about 5°C, about 6°C, about 7°C, about 8°C, about 9°C, about 10°C, about 11°C, about 12°C, about 13°C, about 14°C, about 15°C, about 16°C, about 17°C, about 18°C, about 19°C, about 20°C, about 21°C, about 22°C, about 23°C, about 24°C, about 25°C, or higher.In embodiments, HaSMaN is formed by incubating detergent-core nanoparticles with ISCOM matrix adjuvant at a temperature of at least about 4°C, at least about 5°C, at least about 6°C, at least about 7°C, at least about 8°C, at least about 9°C, at least about 10°C, at least about 11°C, at least about 12°C, at least about 13°C, at least about 14°C, at least about 15°C, at least about 16°C, at least about 17°C, at least about 18°C, at least about 19°C, at least about 20°C, at least about 21°C, at least about 22°C, at least about 23°C, at least about 24°C, at least about 25°C. Typically, about 24-48 hours of incubation at 4°C or 25°C is required for formation. Formation of HaSMaN is facilitated by higher temperatures. In embodiments, formation of HaSMaN occurs by incubating detergent-core nanoparticles with ISCOM matrix adjuvant at about 25°C for at least 24 hours. Mixing detergent core nanoparticles with ISCOM matrix adjuvant immediately prior to administration to a subject, i.e., bedside mix, does not generate HaSMaN. Longer incubation periods do not adversely affect the formation of HaSMaN.

[0230] Fabrication of detergent-core nanoparticles The nanoparticles of the present disclosure are non-naturally occurring products, and their components do not occur together in nature. In an embodiment, the method disclosed herein uses a detergent exchange approach, in which a first detergent is used to isolate proteins, and then the first detergent is exchanged with a second detergent to form nanoparticles.

[0231] Antigens contained in nanoparticles are typically produced by recombinant expression in host cells. Standard recombinant techniques can be used. In embodiments, CoV S polypeptides are expressed in insect host cells using the baculovirus system. In embodiments, the baculovirus is a cathepsin-L knockout baculovirus, a chitinase knockout baculovirus. Optionally, the baculovirus is a double knockout for both cathepsin L and chitinase. High levels of expression can be obtained in insect cell expression systems. Non-limiting examples of insect cells are Spodoptera frugiperda (Sf) cells, such as Sf9, Sf21, Trichoplusiani cells, such as High Five cells, and Drosophila S2 cells. In embodiments, the CoV S polypeptides or hemagglutinins described herein are produced in any suitable host cell. In embodiments, the host cell is an insect cell. In embodiments, the insect cell is an Sf9 cell.

[0232] Typical transfection and cell growth methods can be used to culture the cells. A vector, for example a vector containing a polynucleotide encoding a fusion protein, can be transfected into a host cell according to methods well known in the art. For example, the introduction of nucleic acid into eukaryotic cells can be achieved by calcium phosphate co-precipitation, electroporation, microinjection, lipofection, and transfection using polyamine transfection reagent. In one embodiment, the vector is a recombinant baculovirus.

[0233] Methods for growing host cells include, but are not limited to, batch, fed-batch, continuous, and perfusion cell culture techniques. Cell culture refers to the growth and propagation of cells in a bioreactor (fermentation chamber) where cells grow to express proteins (e.g., recombinant proteins) for purification and isolation. Typically, cell culture is performed in a bioreactor that is sterile and under controlled temperature and atmospheric conditions. A bioreactor is a chamber used to culture cells where environmental conditions such as temperature, atmosphere, agitation, and / or pH can be monitored. In one embodiment, the bioreactor is a stainless steel chamber. In another embodiment, the bioreactor is a pre-sterilized plastic bag (e.g., Celbag®, Wave Biotech, Bridgewater, NJ). In other embodiments, the pre-sterilized plastic bag is a bag of about 50 L to 3500 L.

[0234] Nanoparticle extraction and purification After growth of the host cells, the proteins or nanoparticles can be recovered from the host cells using detergents and purification protocols. Once the host cells have grown for 48-96 hours, the cells are isolated from the medium and a detergent-containing solution is added to solubilize the cell membrane and release the proteins into the detergent extract. Triton X-100, also known as NP-9, and TERGITOL® nonylphenol ethoxylate, respectively, are preferred detergents for extraction. The detergent may be added to a final concentration of about 0.1% to about 1.0%. For example, the concentration may be about 0.1%, about 0.2%, about 0.3%, about 0.5%, about 0.7%, about 0.8%, or about 1.0%. The range can be about 0.1% to about 0.3%. In an embodiment, the concentration is about 0.5%.

[0235] In aspects of the embodiment, various first detergents can be used to isolate proteins from host cells. For example, the first detergents can be bis(polyethylene glycol bis[imidazoyl carbonyl]), nononoxynol-9, bis(polyethylene glycol bis[imidazoyl carbonyl]), BRIJ® Polyethylene Glycol Dodecyl Ether 35, BRIJ® Polyethylene Glycol (3) Cetyl Ether 56, BRIJ® Alcohol Ethoxylate 72, BRIJ® Polyoxyl 2 Stearyl Ether 76, BRIJ® Polyethylene Glycol Monooleyl Ether 92V, BRIJ® Polyoxyethylene (10) Oleyl Ether 97, BRIJ® Polyethylene Glycol Hexadecyl Ether 58P, CREMOPHOR® EL Macrogoglycerol ... Phosphoric Ricinoleic Acid, Decaethylene Glycol Monododecyl Ether, N-Decanoyl-N-Methylglucamine, N-Decyl Alpha-Diglucopyranoside, Decyl Beta-D-Maltopyranoside, N-Dodecanoyl-N-Methylglucamide, N-Dodecyl Alpha-D-Maltoside, N-Dodecyl Beta-D-Maltoside, N-Dodecyl Beta-D-Maltoside, Heptaethylene Glycol Monodecyl Ether, Heptaethylene Glycol Monotetradecyl Ether, N-Hexadecyl Beta-D-Maltoside, Hexaethylene Glycol Monododecyl Ether, Hexaethylene Glycol Monohexadecyl Ether, Hexaethylene Glycol Monooctadecyl Ether, Hexaethylene Glycol Monotetradecyl Ether, Igepal CA-630, Igepal CA-630, Methyl-6-0-(N-heptylcarbamoyl)-alpha-D-gluconopyranoside, Nonaethylene monododecyl ether, N-nonanoyl-N-methylglucamine, N-nonanoyl N-methylglucamine, Octaethylene glycol monodecyl ether, Octaethylene glycol monododecyl ether, Octaethylene glycol monohexadecyl ether, Octaethylene glycol monooctadecyl ether, Octaethylene glycol monotetradecyl ether, Octyl-beta-D glucopyranoside, Pentaethylene glycol monodecyl ether,Pentaethylene glycol monododecyl ether, pentaethylene glycol monohexadecyl ether, pentaethylene glycol monohexyl ether, pentaethylene glycol monooctadecyl ether, pentaethylene glycol monooctyl ether, pentaethylene glycol diglycidyl ether, polyethylene glycol ether W-1, polyoxyethylene 10 tridecyl ether, polyoxyethylene 100 stearate, polyoxyethylene 20 isohexadecyl ether, polyoxyethylene 20 oleyl ether , Polyoxyethylene 40 Stearate, Polyoxyethylene 50 Stearate, Polyoxyethylene 8 Stearate, Polyoxyethylene Bis(imidazolylcarbonyl), Polyoxyethylene 25 Propylene Glycol Stearate, Saponin from Quillaja Bark, SPAN® 20 Sorbitan Laurate, SPAN® 40 Sorbitan Monopalmitate, SPAN® 60 Sorbitan Stearate, SPAN® 65 Sorbitan Tristearate, SPAN® 80 Sorbitan Monooleate, S PAN® 85 Sorbitan Trioleate, TERGITOL® Secondary Alcohol Ethoxylate Type 15-S-12, TERGITOL® Secondary Alcohol Ethoxylate Type 15-S-30, TERGITOL® Secondary Alcohol Ethoxylate Type 15-S-5, TERGITOL® Secondary Alcohol Ethoxylate Type 15-S-7, TERGITOL® Secondary Alcohol Ethoxylate Type 15-S-9, TERGITOL® Nonylphenol Ethoxylate tergitol nonylphenol ethoxylate type NP-10, tergitol nonylphenol ethoxylate type NP-4, tergitol nonylphenol ethoxylate type NP-40, tergitol nonylphenol ethoxylate type NP-7, tergitol nonylphenol ethoxylate type NP-9, tergitol branched secondary alcohol ethoxylate type TMN-10, tergitol branched secondary alcohol ethoxylate type TMN-6,TRITON™ X-100 polyethylene glycol tert-octylphenyl ether, or a combination thereof.

[0236] The nanoparticles can then be isolated from the cell debris using centrifugation. In embodiments, gradient centrifugation, such as using cesium chloride, sucrose, and iodine methanol, can be used. Other techniques, such as standard purification techniques including ion exchange, affinity, and gel filtration chromatography, can be used as an alternative or in addition to these.

[0237] For example, the first column can be an ion exchange chromatography resin, such as FRACTOGEL® EMD methacrylate-based polymer beads TMAE (EMD Millipore), the second column can be a Lens culinaris lectin affinity resin, and the third column can be a cation exchange column, such as FRACTOGEL® EMD methacrylate-based polymer beads SO3 (EMD Millipore) resin. In other embodiments, the cation exchange column can be an MMC column or a Nuvia C Prime column (Bio-Rad Laboratories, Inc.). Preferably, the methods disclosed herein do not use detergent extraction columns, such as hydrophobic interaction columns. Such columns are often used to remove detergent during purification, but can adversely affect the methods disclosed herein.

[0238] In an embodiment, the first detergent used to extract proteins from host cells is substantially replaced by a second detergent to achieve nanoparticle structure. In an embodiment, the first detergent is NP-9. Typically, the nanoparticles do not contain detectable NP-9 as measured by HPLC. The second detergent is typically selected from the group consisting of PS20, PS40, PS60, PS65, and PS80. In an embodiment, the second detergent is PS80.

[0239] In embodiments, detergent exchange is performed using affinity chromatography to bind glycoproteins via their carbohydrate moieties. For example, affinity chromatography can use a legume lectin column. Legume lectins were the first proteins identified in plants and have been found to interact specifically and reversibly with carbohydrate residues. See, for example, Sharon and Lis, "Legume lectins--a large family of homologous proteins," FASEB J. 1990 Nov;4(14):3198-208; Liener, "The Lectins: Properties, Functions, and Applications in Biology and Medicine," Elsevier, 2012. Suitable lectins include concanavalin A (con A), pea lectin, sainfoin lectin, and lentil lectin. Lentil lectin is a preferred column for detergent exchange due to its binding properties. Lectin columns are commercially available, for example Capto Lentil Lectin is available from GE Healthcare. In certain aspects, the lentil lectin column can use recombinant lectin. At the molecular level, it is believed that carbohydrate moieties bind to the lentil lectin, freeing amino acids of the protein to coalesce around the detergent and form a detergent core to provide nanoparticles with multiple copies of the antigen, e.g., glycoprotein oligomers that may be dimers, trimers, or tetramers immobilized in the detergent. In embodiments, the CoV S polypeptide and / or hemagglutinin form trimers. In embodiments, the CoV S polypeptide trimers and / or hemagglutinin are immobilized in the detergent. In embodiments, each nanoparticle comprises at least one trimer associated with a non-ionic core.

[0240] Detergents may be present up to about 0.1% (w / v) during early purification steps when incubated with the protein during detergent exchange to form nanoparticles, and this amount is lowered to achieve final nanoparticles with optimal stability. For example, non-ionic detergents (e.g., PS80) may be present at about 0.005% (v / v) to about 0.1% (v / v), e.g., about 0.005% (v / v), about 0.006% (v / v), about 0.007% (v / v), about 0.008% (v / v), about 0.009% (v / v), about 0.01% (v / v), about 0.015% (v / v), about 0.02% (v / v), about 0.025% (v / v), about 0.03 ... The PS80 may be about 5% (v / v), about 0.04% (v / v), about 0.045% (v / v), about 0.05% (v / v), about 0.055% (v / v), about 0.06% (v / v), about 0.065% (v / v), about 0.0.7% (v / v), about 0.075% (v / v), about 0.08% (v / v), about 0.085% (v / v), about 0.09% (v / v), about 0.095% (v / v), or about 0.1% (v / v). In an embodiment, the nanoparticles comprise about 0.03% to about 0.05% PS80. In an embodiment, the nanoparticles comprise about 0.01% (v / v) PS80.

[0241] In embodiments, the purified CoV S polypeptide and / or hemagglutinin is dialyzed. In embodiments, the dialysis is performed after purification. In embodiments, the CoV S polypeptide and / or hemagglutinin is dialyzed in a solution comprising sodium phosphate, NaCl, and PS80. In embodiments, the dialysis solution comprising sodium phosphate comprises about 5 mM to about 100 mM sodium phosphate, for example, about 5 mM, about 10 mM, about 15 mM, about 20 mM, about 25 mM, about 30 mM, about 35 mM, about 40 mM, about 45 mM, about 50 mM, about 55 mM, about 60 mM, about 65 mM, about 70 mM, about 75 mM, about 80 mM, about 85 mM, about 90 mM, about 95 mM, or about 100 mM sodium phosphate. In an embodiment, the pH of the solution containing sodium phosphate is about 6.5, about 6.6, about 6.7, about 6.8, about 6.9, about 7.0, about 7.1, about 7.2, about 7.3, about 7.4, or about 7.5. In an embodiment, the dialysis solution containing sodium chloride is about 50 mM to about 500 mM NaCl, for example, about 50 mM, about 60 mM, about 70 mM, about 80 mM, about 90 mM, about 100 mM, about 110 mM, about 120 mM, about 130 mM, about 140 mM, about 150 mM, about 160 mM, about 170 mM, about 180 mM, about 190 mM, about 200 mM, about 210 mM, about 220 mM, about 230 mM, about 240 mM, about 250 mM, About 260 mM, about 270 mM, about 280 mM, about 290 mM, about 300 mM, about 310 mM, about 320 mM, about 330 mM, about 340 mM, about 350 mM, about 360 mM, about 370 mM, about 380 mM, about 390 mM, about 400 mM, about 410 mM, about 420 mM, about 430 mM, about 440 mM, about 450 mM, about 460 mM, about 470 mM, about 480 mM, about 490 mM, or about 500 mM NaCl.In embodiments, the dialysis solution containing PS80 is about 0.005% (v / v), about 0.006% (v / v), about 0.007% (v / v), about 0.008% (v / v), about 0.009% (v / v), about 0.01% (v / v), about 0.015% (v / v), about 0.02% (v / v), about 0.025% (v / v), about 0.03% (v / v), about 0.035% (v / v), about 0.04% (v / v), about 0.05% (v / v), about 0.06% (v / v), about 0.07% (v / v), about 0.08% (v / v), about 0.09% (v / v), about 0.1% (v / v), about 0.15 ... (v / v), about 0.045% (v / v), about 0.05% (v / v), about 0.055% (v / v), about 0.06% (v / v), about 0.065% (v / v), about 0.07% (v / v), about 0.075% (v / v), about 0.08% (v / v), about 0.085% (v / v), about 0.09% (v / v), about 0.095% (v / v), or about 0.1% (v / v) PS80. In an embodiment, the dialysis solution comprises about 25 mM sodium phosphate, pH 7.2, about 300 mM NaCl, and about 0.01% (v / v) PS80.

[0242] Detergent exchange can be performed using proteins purified as described above and purified, frozen for storage, and then thawed for detergent exchange.

[0243] The stability of the compositions disclosed herein can be measured in a variety of ways. In one approach, peptide maps can be generated to determine the integrity of antigenic proteins after various treatments designed to stress the nanoparticles by mimicking harsh storage conditions. Thus, a measure of stability is the relative abundance of antigenic peptides in stressed samples compared to control samples. For example, the stability of nanoparticles containing CoV S polypeptides can be assessed by exposing the nanoparticles to various pHs, proteases, salts, oxidizing agents including but not limited to hydrogen peroxide, various temperatures, freeze / thaw cycles, and agitation.

[0244] (iic) At least three hemagglutinins: inactivated whole influenza virus In an embodiment, the at least three hemagglutinins are in the form of a whole influenza virus. The whole influenza virus includes all of its envelope, viral membrane, nucleocapsid, and genetic material. In an embodiment, the whole influenza virus is inactivated as described throughout this disclosure.

[0245] (iid) At least three types of hemagglutinin: hemagglutinin composition extracted from influenza virus In an embodiment, the at least three hemagglutinins are in the form of a hemagglutinin composition extracted from an influenza virus. In an embodiment, the hemagglutinin composition extracted from an influenza virus is an influenza split virion composition or a subunit influenza composition.

[0246] Influenza split virions are influenza viruses in which the influenza virus membrane has been disrupted by a detergent. In embodiments, the detergent is any detergent described herein. In embodiments, the detergent is sodium taurodeoxycholate, octylphenol ethoxylate (Triton®-X100), or cetyltrimethylammonium bromide. In embodiments, influenza split virions are produced using egg-based or cell culture-based production methods. In embodiments, split virions are produced by growing influenza virus in Madin-Darby canine kidney cells (MDCK) cells, inactivating the virus with β-propiolactone, exposing the virus to the detergent cetyltrimethylammonium bromide, and purifying the virions.

[0247] Similar to influenza split virions, subunit influenza compositions are produced by disrupting influenza virus membranes with detergents. However, unlike influenza split virions, subunit influenza compositions are subjected to additional purification. In embodiments, subunit influenza compositions are purified by differential precipitation to remove the inner subviral core. In embodiments, subunit influenza compositions are purified by centrifugation, chromatography, precipitation, or nanofiltration. The detergent can be any detergent described herein. In embodiments, the detergent is sodium taurodeoxycholate, octylphenol ethoxylate (Triton®-X100), or cetyltrimethylammonium bromide. In embodiments, the subunit influenza vaccine is produced using an egg-based or cell culture-based manufacturing method.

[0248] In embodiments, the hemagglutinin composition extracted from a virus comprises hemagglutinin and excludes viral ribonucleoproteins (vRNPs), matrix protein M1, and the viral envelope.

[0249] In embodiments, the virus extracted hemagglutinin composition is obtained by (i) producing whole influenza virus using an egg-based manufacturing method, (ii) harvesting and purifying the whole influenza virus by centrifugation and filtration, (iii) inactivating the influenza virus with formaldehyde, (iv) concentrating and purifying the inactivated influenza virus by zonal centrifugation, and (v) centrifugation of the inactivated influenza virus in the presence of cetyltrimethylammonium bromide.

[0250] Immunogenic composition formulations The present disclosure provides an immunogenic composition comprising: (i) at least three hemagglutinin (HA) glycoproteins, where the three HA glycoproteins are from different influenza strains; (ii) a CoV S polypeptide in the form of a detergent-core nanoparticle, where the detergent is a non-ionic detergent; and (iii) a pharma- ceutically acceptable buffer. In an embodiment, the at least three HA glycoproteins are selected from the group consisting of: (a) detergent core nanoparticles comprising hemagglutinin (HA), (b) HaSMaNs (hemagglutinin saponin matrix nanoparticles), (c) influenza split virions, (d) whole influenza virus, (e) recombinant hemagglutinin, and (f) hemagglutinin compositions extracted from viruses. In an embodiment, the immunogenic composition may comprise nanoparticles bearing antigens from two or more virus strains from the same species of virus.

[0251] In an embodiment, the immunogenic composition comprises (i) a CoV S polypeptide in the form of a detergent-core nanoparticle, where the detergent is a non-ionic detergent, and (ii) at least three hemagglutinin (HA) glycoproteins, where the at least three HA glycoproteins are from different influenza strains and the at least three HA glycoproteins are in the form of a detergent-core nanoparticle comprising HA glycoproteins and in the form of HaSMaN. In an embodiment, the immunogenic composition comprises (i) at least three hemagglutinin (HA) glycoproteins, where the at least three HA glycoproteins are from different influenza strains and the at least three HA glycoproteins are in the form of influenza split virions, and (ii) a CoV S polypeptide in the form of a detergent-core nanoparticle, where the detergent is a non-ionic detergent. In embodiments, the immunogenic composition comprises (i) at least three hemagglutinin (HA) glycoproteins, wherein the at least three HA glycoproteins are from different influenza strains, and the at least three HA glycoproteins are in the form of a hemagglutinin composition extracted from a virus; and (ii) a CoV S polypeptide in the form of a detergent-core nanoparticle, wherein the detergent is a non-ionic detergent.

[0252] In an embodiment, the composition comprises about 1 to about 10 detergent-core nanoparticles comprising hemagglutinin and HaSMaN, e.g., about 1, about 2, about 3, about 4, about 5, about 6, about 7, about 8, about 9, or about 10 total nanoparticles. In an embodiment, each detergent-core nanoparticle and HaSMaN comprises hemagglutinin from a different influenza strain. In an embodiment, each of the HaSMaN comprises hemagglutinin from an influenza A strain. In an embodiment, the hemagglutinin from each of the detergent-core nanoparticles is from an influenza B strain. In an embodiment, each of the HaSMaN comprises hemagglutinin from an influenza B strain. In an embodiment, the hemagglutinin from each of the detergent-core nanoparticles is from an influenza A strain. In an embodiment, the hemagglutinin from each of the detergent-core nanoparticles is from an influenza B strain and the hemagglutinin from each of the HaSMaN is from an influenza A strain. In an embodiment, the composition comprises detergent-core nanoparticles comprising a total of four hemagglutinins and HaSMaN, In an embodiment, the composition comprises detergent-core nanoparticles comprising a total of three hemagglutinins and HaSMaN.

[0253] In another embodiment, the disclosure provides a pharmaceutical pack or kit comprising one or more containers filled with one or more of the ingredients of the immunogenic composition.

[0254] The compositions disclosed herein may be used prophylactically or therapeutically, but are typically prophylactic. Thus, the present disclosure includes a method for treating or preventing infection. The method includes administering to a subject a therapeutic or prophylactic amount of the immunogenic composition of the present disclosure. In an embodiment, the pharmaceutical composition is a vaccine composition that provides a protective effect. In an embodiment, the protective effect includes an improvement in symptoms associated with infection in a percentage of an exposed population. For example, the composition can prevent or reduce one or more symptoms of viral disease selected from fever fatigue, muscle pain, headache, sore throat, vomiting, diarrhea, rash, symptoms of impaired kidney and liver function, internal bleeding and external bleeding, compared to untreated subjects.

[0255] These nanoparticles may be formulated for administration as a vaccine in the presence of various excipients, buffers, etc. For example, the vaccine composition may include sodium phosphate, sodium chloride, and / or histidine. Sodium phosphate may be present at about 10 mM to about 50 mM, about 15 mM to about 25 mM, or about 25 mM, and in particular, about 22 mM sodium phosphate is present. Histidine may be present at about 0.1% (w / v), about 0.5% (w / v), about 0.7% (w / v), about 1% (w / v), about 1.5% (w / v), about 2% (w / v), or about 2.5% (w / v). Sodium chloride, if present, may be about 150 mM. In certain compositions, sodium chloride may be present at higher concentrations, for example, about 200 mM to about 500 mM. In embodiments, sodium chloride is present at a high concentration, including but not limited to, about 200 mM, about 250 mM, about 300 mM, about 350 mM, about 400 mM, about 450 mM, or about 500 mM.

[0256] In embodiments, the nanoparticles described herein have improved stability at certain pH levels. In embodiments, the nanoparticles are stable at slightly acidic pH levels. For example, the nanoparticles are stable at slightly acidic pH, for example, pH 5.8 to pH 7.0. In embodiments, the nanoparticles and compositions comprising the nanoparticles may be stable at a pH range of about pH 5.8 to about pH 7.0, including about pH 5.9 to about pH 6.8, about pH 6.0 to about pH 6.5, about pH 6.1 to about pH 6.4, about pH 6.1 to about pH 6.3, or about pH 6.2. In embodiments, the nanoparticles and compositions described herein are stable at neutral pH, including about pH 7.0 to about pH 7.4. In embodiments, the nanoparticles and compositions described herein are stable at slightly alkaline pH, for example, about pH 7.0 to about pH 8.5, about pH 7.0 to about pH 8.0, or about pH 7.0 to about pH 7.5, including all values ​​and ranges therebetween. Adjuvants

[0257] In certain embodiments, the compositions disclosed herein can be combined with one or more adjuvants to enhance immune response. In embodiments, the compositions are produced without adjuvants and can therefore be administered as adjuvant-free compositions. Advantageously, the adjuvant-free compositions disclosed herein can provide a protective immune response when administered in a single dose. Alum-free compositions that induce robust immune responses are particularly useful in adults over about 60 years of age. In embodiments, the adjuvant is an oil-in-water emulsion composed of squalene as the oil phase, stabilized with surfactants, polysorbate 80 and sorbitan trioleate, in a citrate buffer. Aluminum-based adjuvants

[0258] In embodiments, the adjuvant can be alum (e.g., AlPO4 or Al(OH)3). Typically, the nanoparticles are substantially bound to the alum. For example, the nanoparticles may be at least 80% bound, at least 85% bound, at least 90% bound, or at least 95% bound to the alum. Often, the nanoparticles are 92% to 97% bound to the alum in the composition. The amount of alum present per dose typically ranges between about 400 μg to about 1250 μg. For example, the alum can be present at about 300 μg to about 900 μg, about 400 μg to about 800 μg, about 500 μg to about 700 μg, about 400 μg to about 600 μg, or about 400 μg to about 500 μg per dose. Typically, alum is present at about 400 μg for a 120 μg dose of protein nanoparticles.

[0259] Saponin adjuvants Adjuvants containing saponins can also be combined with the immunogens disclosed herein. Saponins are glycosides derived from the bark of the Quillaja saponaria Molina tree. Typically, saponins are prepared using a multi-step purification process, resulting in multiple fractions. As used herein, the term "saponin fraction from Quillaja saponaria Molina" is used generally to describe a semi-purified or defined saponin fraction of Quillaja saponaria or a substantially pure fraction thereof. Saponin fraction

[0260] Several approaches to producing saponin fractions are suitable. Fractions A, B, and C are described in U.S. Pat. No. 6,352,697 and may be prepared as follows: The lipophilic fraction from the crude aqueous Quillaja saponaria Molina extract, Quil A, is separated by chromatography and eluted with 70% acetonitrile in water to recover the lipophilic fraction. This lipophilic fraction is then separated by semi-preparative HPLC eluting with a gradient of 25% to 60% acetonitrile in acidic water. The fraction referred to herein as "Fraction A" or "QH-A" is or corresponds to the fraction eluted at about 39% acetonitrile. The fraction referred to herein as "Fraction B" or "QH-B" is or corresponds to the fraction eluted at about 47% acetonitrile. The fraction referred to herein as "Fraction C" or "QH-C" is or corresponds to the fraction eluted at about 49% acetonitrile. Additional information regarding purification of the fractions can be found in U.S. Patent No. 5,057,540. When prepared as described herein, Quillaja saponaria Molina fractions A, B, and C each represent a group or family of closely chemically related molecules with definable properties. The chromatographic conditions under which they were obtained are those that are highly reproducible and consistent batch-to-batch in terms of elution profile and biological activity.

[0261] Other saponin fractions have been described: fractions B3, B4, and B4b are described in EP 0436620; fractions QA1 to QA22 are described in EP 03632279 B2, Q-VAC (Nor-Feed, ASDenmark), Quillaja saponaria Molina Spikoside (Isconova AB, Ultunaallen 2B, 756 51 Uppsala, Sweden). Fractions QA-1, QA-2, QA-3, QA-4, QA-5, QA-6, QA-7, QA-8, QA-9, QA-10, QA-11, QA-12, QA-13, QA-14, QA-15, QA-16, QA-17, QA-18, QA-19, QA-20, QA-21 and QA-22 of EP 0 3632 279 B2 may be used, in particular QA-7, QA-17, QA-18 and QA-21. These are obtained as described in EP 0 3632 279 B2, in particular on page 6, and in Example 1 on pages 8 and 9.

[0262] The saponin fractions described herein and used to form adjuvants are often substantially pure fractions, i.e., the fractions have substantially no contamination from other materials present. In certain embodiments, a substantially pure saponin fraction may contain up to 40%, up to 30%, up to 25%, up to 20%, up to 15%, up to 10%, up to 7%, up to 5%, up to 2%, up to 1%, up to 0.5%, or up to 0.1% by weight of other compounds, such as other saponins or other adjuvant substances.

[0263] ISCOM Structure The saponin fraction may be administered in the form of cage-like particles called ISCOMs (Immune Stimulating COMplexes). ISCOMs can be prepared as described in EP0109942B1, EP0242380B1, and EP0180546 B1. In certain embodiments, transport and / or passenger antigens can be used as described in EP 9600647-3 (PCT / SE97 / 00289).

[0264] Matrix adjuvants In an embodiment, the ISCOM is an ISCOM matrix complex. The ISCOM matrix complex comprises at least one saponin fraction and a lipid. The lipid is at least one sterol, such as cholesterol. In certain aspects, the ISCOM matrix complex also comprises a phospholipid. The ISCOM matrix complex may also contain one or more other immunomodulatory (adjuvant-active) substances that are not necessarily glycosides, and may be prepared as described in EP0436620B1, which is incorporated herein by reference in its entirety.

[0265] In other embodiments, the ISCOM is an ISCOM complex. An ISCOM complex comprises at least one saponin, at least one lipid, and at least one antigen or epitope. An ISCOM complex comprises an antigen that is associated with the particle by detergent treatment such that a portion of the antigen becomes integrated into the particle. In contrast, ISCOM matrices are prepared as an admixture with the antigen, and the association of the ISCOM matrix particles with the antigen is mediated by electrostatic and / or hydrophobic interactions.

[0266] According to one embodiment, the ISCOM matrix complex or the saponin fraction incorporated into the ISCOM complex, or at least one additional adjuvant also incorporated or mixed into the ISCOM or ISCOM matrix complex, is selected from fraction A, fraction B, or fraction C of Quillaja saponaria, a semi-purified preparation of Quillaja saponaria, a purified preparation of Quillaja saponaria, or any purified subfraction, e.g., QA 1-21.

[0267] In certain embodiments, each ISCOM particle may contain at least two saponin fractions. Any combination of different saponin fractions may be used. Any combination of weight percent of any two fractions may be used. For example, the particle may contain any weight percent of fraction A and any weight percent of another saponin fraction, such as a crude saponin fraction or fraction C, respectively. Thus, in certain embodiments, each ISCOM matrix particle or each ISCOM complex particle may comprise 0.1-99.9%, 5-95%, 10-90%, 15-85%, 20-80%, 25-75%, 30-70%, 35-65%, 40-60%, 45-55%, 40-60%, or 50% by weight of one saponin fraction, e.g., fraction A, and the remainder, in each case up to 100%, of another saponin, e.g., any crude fraction or any other fraction, e.g., fraction C. The weights are calculated as the total weight of the saponin fractions. Examples of ISCOM matrix complexes and ISCOM complex adjuvants are disclosed in US Patent Application Publication No. 2013 / 0129770, which is incorporated herein by reference in its entirety.

[0268] In certain embodiments, an ISCOM matrix or ISCOM complex comprises 5-99% by weight of one fraction, such as fraction A, and the remainder up to 100% of another fraction, such as the crude saponin fraction or fraction C. The weights are calculated as the total weight of the saponin fractions.

[0269] In another embodiment, the ISCOM matrix or ISCOM complex comprises 40% to 99% by weight of one fraction, such as fraction A, and 1% to 60% by weight of another fraction, such as the crude saponin fraction or fraction C. The weights are calculated as the total weight of the saponin fractions.

[0270] In yet another embodiment, the ISCOM matrix or ISCOM complex comprises 70% to 95% by weight of one fraction, such as fraction A, and 30% to 5% by weight of another fraction, such as the crude saponin fraction or fraction C, the weights being calculated as the total weight of the saponin fractions. In another embodiment, the saponin fraction from Quillaja saponaria Molina is selected from any one of QA1-21.

[0271] In addition to particles containing a mixture of saponin fractions, ISCOM matrix particles and ISCOM complex particles may each be formed using only one saponin fraction. The compositions disclosed herein may include a plurality of particles, each containing only one saponin fraction. That is, a particular composition may include one or more different types of ISCOM matrix complex particles and / or one or more different types of ISCOM complex particles, each containing one saponin fraction from Quillaja saponaria Molina, and the saponin fraction in one complex is different from the saponin fraction in the other complex particles.

[0272] In certain embodiments, one type of saponin fraction or crude saponin fraction may be incorporated into one ISCOM matrix complex or particle and another type of substantially pure saponin fraction or crude saponin fraction may be incorporated into another ISCOM matrix complex or particle. A composition or vaccine may comprise at least two types of complexes or particles, each type of complex or particle having one type of saponin incorporated into a physically distinct particle.

[0273] The composition may also use a mixture of ISCOM matrix complex particles and / or ISCOM complex particles in which one saponin fraction Quillaja saponaria Molina and another saponin fraction Quillaja saponaria Molina are separately incorporated into different ISCOM matrix complex particles and / or ISCOM complex particles.

[0274] ISCOM matrices or ISCOM complex particles, each having one saponin fraction, may be present in the composition in any combination of weight percent. In certain embodiments, the composition comprises 0.1%-99.9%, 5%-95%, 10%-90%, 15%-85%, 20%-80%, 25%-75%, 30%-70%, 35%-65%, 40%-60%, 45%-55%, 40%-60%, or 50% by weight of an ISCOM matrix or a first saponin fraction, with the remainder being made up of ISCOM matrices or complexes containing different saponin fractions. In some embodiments, the remainder is one or more ISCOM matrices or complexes, each matrix or complex particle containing only one saponin fraction. In other embodiments, an ISCOM matrix or complex particle may contain two or more saponin fractions.

[0275] In certain compositions, the only saponin fraction in a first ISCOM matrix or ISCOM complex particle is fraction A and the only saponin fraction in a second ISCOM matrix or ISCOM complex particle is fraction C.

[0276] A preferred composition comprises a first ISCOM matrix comprising fraction A and a second ISCOM matrix comprising fraction C, where the fraction A ISCOM matrix comprises about 70% by weight of the total saponin adjuvant and the fraction C ISCOM matrix comprises about 30% by weight of the total saponin adjuvant. In another preferred composition, the fraction A ISCOM matrix comprises about 85% by weight of the total saponin adjuvant and the fraction C ISCOM matrix comprises about 15% by weight of the total saponin adjuvant. Thus, in certain compositions, the fraction A ISCOM matrix is ​​present in a range of about 70% to about 85% of the total weight of the saponin adjuvant in the composition and the fraction C ISCOM matrix is ​​present in a range of about 15% to about 30% of the total weight of the saponin adjuvant in the composition. In embodiments, the Fraction A ISCOM matrix comprises 50-96% by weight of the combined weight of the Fraction A ISCOM matrix and Fraction C ISCOM matrix in the adjuvant, with the Fraction C ISCOM matrix comprising the remainder. In a particularly preferred composition, referred to herein as MATRIX-M™, the Fraction A ISCOM matrix is ​​present at about 85% of the total weight of the saponin adjuvant in the composition, and the Fraction C type ISCOM matrix is ​​present at about 15% of the total weight of the saponin adjuvant in the composition. MATRIX-M™ may be referred to interchangeably as MATRIX-M1.

[0277] Exemplary QS-7 and QS-21 fractions, their preparation and their uses are described in U.S. Pat. Nos. 5,057,540, 6,231,859, 6,352,697, 6,524,584, 6,846,489, 7,776,343 and 8,173,141, the contents of which are incorporated herein by reference.

[0278] In embodiments, other adjuvants may additionally or alternatively be used. Inclusion of any adjuvant described in Vogel et al., "A Compendium of Vaccine Adjuvants and Excipients (2nd Edition)," which is incorporated by reference in its entirety for all purposes, is contemplated within the scope of this disclosure. Other adjuvants include Freund's complete adjuvant (a non-specific stimulator of the immune response that contains killed Mycobacterium tuberculosis), incomplete Freund's adjuvant, and aluminum hydroxide adjuvant. Other adjuvants include GMCSP, BCG, MDP compounds such as thur-MDP and nor-MDP, CGP (MTP-PE), lipid A and monophosphoryl lipid A (MPL), MF-59, RIBI, which contain three components extracted from bacteria in 2% squalene / TWEEN® polysorbate 80 emulsion, MPL, trehalose dicholate (TDM), and cell wall skeleton (CWS). In an embodiment, the adjuvant may be paucilamellar membrane lipid vesicles, such as NOVASOMES®. NOVASOMES® are paucilamellar membrane nonphospholipid vesicles ranging from about 100 nm to about 500 nm. They contain BRIJ® alcohol ethoxylate 72, cholesterol, oleic acid, and squalene. NOVASOMES® has been shown to be an effective adjuvant (see, e.g., U.S. Pat. Nos. 5,629,021, 6,387,373, and 4,911,928).

[0279] Administration and Dosage In embodiments, the disclosure provides a method for eliciting an immune response against one or more coronaviruses and / or influenza viruses. In embodiments, the response is against one or more of the SARS-CoV-2 virus, MERS, and SARS. In embodiments, the response is against a heterogeneous SARS-CoV-2 strain. Non-limiting examples of heterogeneous SARS-CoV-2 strains include the Cal.20C SARS-CoV-2 strain, the P.1 SARS-CoV-2 strain, the B.1.351 SARS-CoV-2 strain, and the B.1.1.7 SARS-CoV-2 strain. The method includes administering to a subject an immunologically effective amount of an immunogenic composition described herein. Advantageously, the proteins disclosed herein induce one or more particularly useful anti-coronavirus and / or anti-influenza responses.

[0280] In embodiments, the compositions described herein are administered with an adjuvant. In embodiments, the compositions described herein are administered without an adjuvant. In some aspects, the adjuvant can be bound to the nanoparticles, for example, by a non-covalent interaction. In other aspects, the adjuvant is co-administered with the nanoparticles, but does not substantially interact with the nanoparticles.

[0281] In embodiments, the compositions can be used to prevent and / or treat one or more of SARS-CoV-2 infection, heterogeneous SARS-CoV-2 strain infection, SARS infection, MERS infection, and influenza infection, or a combination thereof. Accordingly, the present disclosure provides a method of eliciting an immune response against one or more of SARS-CoV-2 virus, heterogeneous SARS-CoV-2 virus, MERS, SARS, and influenza virus. The method comprises administering to a subject an immunologically effective amount of a composition described herein. Advantageously, the compositions disclosed herein induce a particularly useful anti-coronavirus and / or anti-influenza response.

[0282] In embodiments, the compositions described herein have an efficacy against SARS-CoV-2 virus or a heterogeneous SARS-CoV-2 strain of about 50% to about 99%, about 80% to about 99%, about 75% to about 99%, about 80% to about 95%, about 90% to about 98%, about 75% to about 95%, at least about 50%, at least about 55%, at least about 60%, at least about 65%, at least about 70%, at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 91%, at least about 92%, at least about 93%, at least about 94%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, or at least about 99%. In embodiments, the nanoparticles or CoV S polypeptides described herein have an efficacy against the Cal.20C SARS-CoV-2 strain of about 50% to about 99%, about 80% to about 99%, about 75% to about 99%, about 80% to about 95%, about 90% to about 98%, about 75% to about 95%, at least about 50%, at least about 55%, at least about 60%, at least about 65%, at least about 70%, at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 91%, at least about 92%, at least about 93%, at least about 94%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, or at least about 99%. In embodiments, the nanoparticles or CoV S polypeptides described herein have an efficacy against the P.1 SARS-CoV-2 strain of about 50% to about 99%, about 80% to about 99%, about 75% to about 99%, about 80% to about 95%, about 90% to about 98%, about 75% to about 95%, at least about 50%, at least about 55%, at least about 60%, at least about 65%, at least about 70%, at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 91%, at least about 92%, at least about 93%, at least about 94%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, or at least about 99%.In embodiments, the nanoparticles or CoV S polypeptides described herein have an efficacy against the B.1.351 SARS-CoV-2 strain of about 50% to about 99%, about 80% to about 99%, about 75% to about 99%, about 80% to about 95%, about 90% to about 98%, about 75% to about 95%, at least about 50%, at least about 55%, at least about 60%, at least about 65%, at least about 70%, at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 91%, at least about 92%, at least about 93%, at least about 94%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, or at least about 99%. In embodiments, the nanoparticles or CoV S polypeptides described herein have an efficacy against the B.1.1.7 SARS-CoV-2 strain of about 50% to about 99%, about 80% to about 99%, about 75% to about 99%, about 80% to about 95%, about 90% to about 98%, about 75% to about 95%, at least about 50%, at least about 55%, at least about 60%, at least about 65%, at least about 70%, at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 91%, at least about 92%, at least about 93%, at least about 94%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, or at least about 99%.

[0283] In embodiments, the immunogenicity of the compositions described herein against influenza viruses is determined using an HAI assay or by measuring neutralizing antibodies. Methods for performing HAI assays are described in the following paper, which is incorporated herein by reference in its entirety: Cowling et al. Clin Infect Dis. 2019;68(10):1713-1717. In embodiments, the immunogenicity of the nanoparticle influenza vaccine can be compared to a commercially available influenza vaccine composition. As used herein, a "commercially available influenza vaccine composition" can be any influenza vaccine composition available for medical use. For example, a commercially available influenza vaccine composition can be prepared for trivalent or quadrivalent injection. In embodiments, the injection formulation can include an inactivated form of the virus. In embodiments, the commercially available influenza vaccine composition can be prepared for nasal spray. In embodiments, the formulation for nasal spray can include an attenuated or weakened form of the virus. In embodiments, the compositions disclosed herein induce neutralizing antibodies that bind to influenza strains that have drifted (i.e., undergone slight mutations) relative to sequences used for viruses within the same influenza subtype. In embodiments, one, two, three, four or all of the strains used in the composition induce neutralizing antibodies against one drifted strain, neutralizing antibodies against two drifted strains, neutralizing antibodies against three drifted strains, neutralizing antibodies against four drifted strains, or neutralizing antibodies against five drifted strains.

[0284] The compositions disclosed herein can be administered via systemic or mucosal or transdermal routes or directly to specific tissues. As used herein, the term "systemic administration" includes administration by parenteral routes. In particular, parenteral administration includes subcutaneous, intraperitoneal, intravenous, intraarterial, intramuscular, intrasternal injection, transdermal, intravenous or kidney dialysis infusion techniques. Typically, systemic parenteral administration is intramuscular injection. As used herein, the term "mucosal administration" includes oral, intranasal, intravaginal, intrarectal, intratracheal, intestinal and ophthalmic administration. Preferably, administration is intramuscular.

[0285] The composition can be administered in a single dose schedule or a multiple dose schedule. Multiple doses can be used in a primary immunization schedule or a booster schedule. In a multiple dose schedule, various doses can be given by the same or different routes, e.g., parenteral primary and mucosal boost, mucosal primary and parenteral boost, etc. In aspects, additional boost doses are administered about 2 weeks, about 3 weeks, about 4 weeks, about 5 weeks, or about 6 weeks after the preceding dose. In embodiments, additional boost doses are administered 3 weeks after administration of the preceding dose. According to embodiments, the first dose is administered on day 0 and the boost dose is administered on day 21. According to embodiments, the first dose is administered on day 0 and the boost dose is administered on day 28.

[0286] In embodiments, the dose may be the total weight of the dose including solute, or the weight of the nanoparticles, or the weight of the protein in the nanoparticles (e.g., the weight of hemagglutinin or CoV S polypeptide), measured in μg. The dose is measured using a protein concentration assay, either by A280 or ELISA.

[0287] Doses of CoV S polypeptide, including for administration to children, may range from about 1 μg to about 25 μg, about 3 μg to about 25 μg, about 5 μg to about 25 μg, about 5 μg to about 50 μg, about 1 μg to about 300 μg, about 90 μg to about 270 μg, about 100 μg to about 160 μg, about 110 μg to about 150 μg, about 120 μg to about 140 μg, or about 140 μg to about 160 μg. In embodiments, the dose is about 120 μg administered with alum. In aspects, the dose ranges from about 1 μg to about 90 μg. In embodiments, the dose of CoV spike (S) polypeptide is about 1 μg, about 2 μg, about 3 μg, about 4 μg, about 5 μg, about 6 μg, about 7 μg, about 8 μg, about 9 μg, about 10 μg, about 11 μg, about 12 μg, about 13 μg, about 14 μg, about 15 μg, about 16 μg, about 17 μg, about 18 μg, about 19 μg, about 20 μg, about 21, about 22, about 23, about 24, about 25 μg, about 26 μg, about 27 μg, about 28 μg, about 29 μg, about 30 μg, about 40 μg, about 45 μg, about 46 μg, about 47 μg, about 48 μg, about 49 μg, about 50 μg, about 51 μg, about 52 μg, about 53 μg, about 54 μg, about 55 μg, about 56 μg, about 57 μg, about 58 μg, about 59 μg, about 60 μg, about 61 μg, about 62 μg, about 63 μg, about 64 μg, about 65 μg, about 66 μg, about 67 μg, about 68 μg, about 69 μg, about 70 μg, about 71 μg, about 72 μg, about 73 μg, about 74 μg, about 75 μg, about 76 μg, about 77 μg, about 78 μg, about 79 μg, about 80 μg, about 81 μg, about 82 μg, about 83 μg, about 84 μg, about 85 μg, about 86 μg, about 8 The CoV S polypeptide may be administered in a dose of about 1 μg, about 50, about 60, about 70, about 80, about 90, about 100 μg, about 110 μg, about 120 μg, about 130 μg, about 140 μg, about 150 μg, about 160 μg, about 170 μg, about 180 μg, about 190 μg, about 200 μg, about 210 μg, about 220 μg, about 230 μg, about 240 μg, about 250 μg, about 260 μg, about 270 μg, about 280 μg, about 290 μg, or about 300 μg, including all values ​​and ranges therebetween. In an embodiment, the dose of the CoV S polypeptide is about 3 μg. In an embodiment, the dose of the CoV S polypeptide is about 5 μg. In an embodiment, the dose of the CoV S polypeptide is about 25 μg. In an embodiment, the dose of the CoV S polypeptide is about 20 μg.

[0288] The total amount of hemagglutinin in the immunogenic composition can be in the range of about 25 μg to about 200 μg, about 30 μg to about 150 μg, about 50 μg to about 100 μg, about 45 μg to about 180 μg, about 60 μg to about 190 μg, or about 100 μg to about 200 μg. In certain embodiments, the amount of influenza HA protein in the immunogenic composition may range from about 5 μg per strain to about 80 μg per strain, about 10 μg per strain to about 75 μg per strain, about 15 μg per strain to about 70 μg per strain, about 20 μg per strain to about 65 μg per strain, about 25 μg per strain to about 60 μg per strain, about 30 μg per strain to about 55 μg per strain, about 35 μg per strain to about 50 μg per strain, about 15 μg per strain to about 60 μg per strain. A dose per strain, e.g., 10 μg per strain, refers to a dose of hemagglutinin from a particular strain of influenza. In embodiments, a subject is administered an immunogenic composition comprising about 5 μg to about 100 μg of hemagglutinin per strain.For example, in embodiments, the compositions may comprise about 5 μg, about 6 μg, about 7 μg, about 7.5 μg, about 8 μg, about 9 μg, about 10 μg, about 11 μg, about 12 μg, about 13 μg, about 14 μg, about 15 μg, about 16 μg, about 17 μg, about 18 μg, about 19 μg, about 20 μg, about 21, about 22, about 23, about 24, about 25 μg, about 26 μg, about 27 μg, about 30 μg, about 32 μg, about 34 μg, about 35 μg, about 36 μg, about 37 μg, about 38 μg, about 39 μg, about 40 μg, about 41 μg, about 42 μg, about 43 μg, about 44 μg, about 45 μg, about 46 μg, about 47 μg, about 48 μg, about 49 μg, about 50 μg, about 51 μg, about 52 μg, about 53 μg, about 54 μg, about 55 μg, about 56 μg, about 57 μg, about 58 μg, about 59 μg, about 60 μg, about 61 μg, about 62 μg, about 63 μg, about 64 μg, about 65 μg, about 66 μg, about 67 μg, about 68 μg, about 69 μg, about 70 μg, about 71 μg, about 72 μg, about 73 μg, about 74 μg, about 75 μg, about 76 μg, about 77 μg, about 78 μg, about 79 μg, about 80 μg, about μg, approximately 28 μg, approximately 29 μg, approximately 30 μg, approximately 31 μg, approximately 32 μg, approximately 33 μg, approximately 34 μg, approximately 35 μg, approximately 36 μg, approximately 37 μg, approximately 38 μg, approximately 39 μg, approximately 40μg, about 41μg, about 42μg, about 43μg, about 44μg, about 45μg, about 46μg, about 47μg, about 48μg, about 49μg, about 50μg, about 51μg, about 52μg , about 53μg, about 54μg, about 55μg, about 56μg, about 57μg, about 58μg, about 59μg, about 60μg, about 61μg, about 62μg, about 63μg, about 64μg, about 65 μg, approximately 66 μg, approximately 67 μg, approximately 68 μg, approximately 69 μg, approximately 70 μg, approximately 71 μg, approximately 72 μg, approximately 73 μg, approximately 74 μg, approximately 75 μg, approximately 76 μg, approximately 77 μg, approximately The composition may comprise 78 μg, about 79 μg, about 80 μg, about 81 μg, about 82 μg, about 83 μg, about 84 μg, about 85 μg, about 86 μg, about 87 μg, about 88 μg, about 89 μg, about 90 μg, about 91 μg, about 92 μg, about 93 μg, about 94 μg, about 95 μg, about 96 μg, about 97 μg, about 98 μg, about 99 μg, or about 100 μg of hemagglutinin. In an embodiment, the composition comprises 24 μg to 40 μg of hemagglutinin per strain.

[0289] In embodiments, the patient is administered an immunogenic composition comprising about 5-60 μg hemagglutinin and about 2.5-22.5 μg CoV S polypeptide per strain. In embodiments, the composition comprises about 24 μg-40 μg hemagglutinin and 5 μg to about 25 μg CoV S polypeptide per strain. In embodiments, the immunogenic composition comprises 5 μg, 10 μg, 35 μg, or 60 μg hemagglutinin per strain. In embodiments, the immunogenic composition comprises 2.5 μg, 7.5 μg, or 22.5 μg CoV S polypeptide. In embodiments, the immunogenic composition comprises hemagglutinin from three or four influenza strains. In embodiments, the immunogenic composition comprises about 40 μg of a saponin adjuvant, such as MATRIX-M™. In an embodiment, the immunogenic composition comprises about 50 μg of a saponin adjuvant, such as MATRIX-M™. In an embodiment, the dose of hemagglutinin and the dose of CoV S polypeptide per strain are found in Table 1H.

[0290] In an embodiment, the patient is administered a booster dose of the immunogenic composition on days 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, or 61 after the first administration of the immunogenic composition. In an embodiment, the patient is administered a booster dose of the immunogenic composition on day 56 after the first administration of the immunogenic composition. In an embodiment, the patient is administered a booster dose of the immunogenic composition on day 56 (+5 days) after the first administration of the immunogenic composition. In an embodiment, the booster dose comprises the same amount of hemagglutinin per strain and CoV S polypeptide as the initial dose. In an embodiment, the booster dose comprises a different amount of hemagglutinin per strain, CoV S polypeptide, or a combination thereof than the initial dose. In an embodiment, the amount of hemagglutinin per strain and the amount of CoV S polypeptide in the booster dose of the immunogenic composition is selected from Table 1H. [Table 9]

[0291] In an embodiment, the patient is administered a first immunogenic composition comprising about 5-60 μg hemagglutinin per strain and a second immunogenic composition comprising about 2.5-22.5 μg CoV S polypeptide. In an embodiment, the first immunogenic composition comprises about 5 μg, about 10 μg, about 35 μg, or about 60 μg hemagglutinin per strain. In an embodiment, the second immunogenic composition comprises about 2.5 μg, about 7.5 μg, about 22.5 μg, or about 25 μg CoV S polypeptide. In an embodiment, the first immunogenic composition comprises hemagglutinin from three or four influenza strains. In an embodiment, the amount of hemagglutinin per strain in the first immunogenic composition and the amount of CoV S polypeptide in the second immunogenic composition are set forth in Table 1H. In an embodiment, the first immunogenic composition, the second immunogenic composition, or both, comprises about 50 μg of a saponin adjuvant, e.g., MATRIX-M™. In an embodiment, the patient is administered a booster dose of the first immunogenic composition, the second immunogenic composition, or both, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, or 61 days after the initial administration of the first immunogenic composition, the second immunogenic composition, or both. In an embodiment, the patient is administered a booster dose of the immunogenic composition 56 days after the initial administration of the first immunogenic composition, the second immunogenic composition, or both. In an embodiment, the patient is administered a booster dose of the immunogenic composition 56 days (+5 days) after the initial administration of the first immunogenic composition, the second immunogenic composition, or both. In an embodiment, the booster dose comprises the same amount of hemagglutinin and CoV S polypeptide per strain as the initial dose. In an embodiment, the booster dose comprises a different amount of hemagglutinin, CoV S polypeptide, or a combination thereof per strain than the initial dose. In an embodiment, the amount of hemagglutinin and the amount of CoV S polypeptide per strain in the booster dose of the first or second immunogenic composition is selected from Table 1H. Certain populations may be administered with or without an adjuvant. In certain aspects, the composition may not include an additional adjuvant. In such circumstances, the dose may be increased by about 10%.

[0292] In embodiments, the patient is administered a dose of about 24 μg to about 40 μg hemagglutinin and greater than about 20 μg CoV S polypeptide per strain. In embodiments, the patient is administered a dose of 24-40 μg hemagglutinin and about 25 μg CoV S polypeptide per strain.

[0293] In an embodiment, the dose of the adjuvant is about 1 μg to about 100 μg, for example, about 1 μg, about 2 μg, about 3 μg, about 4 μg, about 5 μg, about 6 μg, about 7 μg, about 8 μg, about 9 μg, about 10 μg, about 11 μg, about 12 μg, about 13 μg, about 14 μg, about 15 μg, about 16 μg, about 17 μg, about 18 μg, about 19 μg, about 20 μg, about 21, about 22, about 23, Approximately 24, approximately 25μg, approximately 26μg, approximately 27μg, approximately 28μg, approximately 29μg, approximately 30μg, approximately 31μg, approximately 32μg, approximately 33μg, approximately 34μg, approximately 35μg, approximately 36μg, approximately 37 μg, approximately 38 μg, approximately 39 μg, approximately 40 μg, approximately 41 μg, approximately 42 μg, approximately 43 μg, approximately 44 μg, approximately 45 μg, approximately 46 μg, approximately 47 μg, approximately 48 μg, approximately 49 μg, approximately 50 μg g, about 51μg, about 52μg, about 53μg, about 54μg, about 55μg, about 56μg, about 57μg, about 58μg, about 59μg, about 60μg, about 61μg, about 62μg, about 63μg , about 64μg, about 65μg, about 66μg, about 67μg, about 68μg, about 69μg, about 70μg, about 71μg, about 72μg, about 73μg, about 74μg, about 75μg, about 76μg, The adjuvant is about 77μg, about 78μg, about 79μg, about 80μg, about 81μg, about 82μg, about 83μg, about 84μg, about 85μg, about 86μg, about 87μg, about 88μg, about 89μg, about 90μg, about 91μg, about 92μg, about 93μg, about 94μg, about 95μg, about 96μg, about 97μg, about 98μg, about 99μg, or about 100μg. In an embodiment, the dose of the adjuvant is about 50μg. In an embodiment, the adjuvant is a saponin adjuvant, such as MATRIX-M™.

[0294] In embodiments, the dose is administered in a volume of about 0.1 mL to about 1.5 mL, e.g., about 0.1 mL, about 0.2 mL, about 0.25 mL, about 0.3 mL, about 0.4 mL, about 0.5 mL, about 0.6 mL, about 0.7 mL, about 0.8 mL, about 0.9 mL, about 1.0 mL, about 1.1 mL, about 1.2 mL, about 1.3 mL, about 1.4 mL, or about 1.5 mL. In embodiments, the dose is administered in a volume of 0.25 mL. In embodiments, the dose is administered in a volume of 0.5 mL. In embodiments, the dose is administered in a volume of 0.6 mL.

[0295] In embodiments, the dose may have a concentration of CoV S polypeptide or hemagglutinin from about 1 μg / mL to about 50 μg / mL, 10 μg / mL to about 100 μg / mL, about 10 μg / mL to about 50 μg / mL, about 175 μg / mL to about 325 μg / mL, about 200 μg / mL to about 300 μg / mL, about 220 μg / mL to about 280 μg / mL, or about 240 μg / mL to about 260 μg / mL.

[0296] In embodiments, the immunogenic compositions described herein are administered in combination with an additional immunogenic composition. In embodiments, the additional immunogenic composition induces an immune response against SARS-CoV-2. In embodiments, the additional immunogenic composition is administered within about 1 minute, about 5 minutes, about 10 minutes, about 20 minutes, about 30 minutes, about 40 minutes, about 50 minutes, about 1 hour, about 2 hours, about 3 hours, about 4 hours, about 5 hours, about 6 hours, about 7 hours, about 8 hours, about 9 hours, about 10 hours, about 11 hours, about 12 hours, about 13 hours, about 14 hours, about 15 hours, about 16 hours, about 17 hours, about 18 hours, about 19 hours, about 20 hours, about 21 hours, or about 24 hours of the disclosed immunogenic composition. Within about 22 hours, within about 23 hours, within about 1 day, within about 2 days, within about 3 days, within about 4 days, within about 5 days, within about 6 days, within about 7 days, within about 8 days, within about 9 days, within about 10 days, within about 11 days, within about 12 days, within about 13 days, within about 14 days, within about 15 days, within about 16 days, within about 17 days, within about 18 days, within about 19 days, within about 20 days, within about 21 days, within about 22 days, within about 23 days, within about 24 days, within about 25 days, within about 26 days, within about 27 days, within about 28 days, within about 29 days, within about 30 days, or within about 31 days. In embodiments, the additional composition is administered with a first dose of a composition described herein. In embodiments, the additional composition is administered with an additional dose of a composition comprising a CoV S polypeptide or nanoparticle, detergent-core nanoparticle, HaSMaN, or a combination thereof. In an embodiment, the additional composition is administered with (a) a first immunogenic composition comprising (i) a CoV S glycoprotein in the form of a detergent-core nanoparticle, where the detergent is a non-ionic detergent, and (ii) a pharma- ceutically acceptable buffer, and (b) a second immunogenic composition comprising (i) at least three HA glycoproteins, where each HA glycoprotein is from a different influenza strain, and (ii) a pharma- ceutically acceptable buffer. In an embodiment, the additional composition is administered with an initial dose of the first immunogenic composition and / or the second immunogenic composition. In an embodiment, the additional composition is administered with an additional dose of the first immunogenic composition and / or the second immunogenic composition.

[0297] In embodiments, provided herein is a method for inducing an immune response against one or more coronaviruses and / or influenza viruses comprising administering an immunogenic composition as described herein. In embodiments, provided herein is a method for inducing an immune response against one or more coronaviruses and / or influenza viruses comprising: (a) administering a first immunogenic composition comprising (i) a CoV S glycoprotein in the form of a detergent-core nanoparticle, where the detergent is a non-ionic detergent, and (ii) a pharmaceutically acceptable buffer, and (b) administering a second immunogenic composition comprising (i) at least three HA glycoproteins, where each HA glycoprotein is from a different influenza strain, and (ii) a pharmaceutically acceptable buffer. In embodiments, the first immunogenic composition is administered about 20 minutes, about 30 minutes, about 40 minutes, about 50 minutes, about 1 hour, about 2 hours, about 3 hours, about 4 hours, about 5 hours, about 6 hours, about 7 hours, about 8 hours, about 9 hours, about 10 hours, about 11 hours, about 12 hours, about 13 hours, about 14 hours, about 15 hours, about 16 hours, about 17 hours, about 18 hours, about 19 hours, about 20 hours, about 21 hours, about 22 hours, about 23 hours, or about 1 day before the second immunogenic composition. In an embodiment, the first immunogenic composition is administered about 20 minutes, about 30 minutes, about 40 minutes, about 50 minutes, about 1 hour, about 2 hours, about 3 hours, about 4 hours, about 5 hours, about 6 hours, about 7 hours, about 8 hours, about 9 hours, about 10 hours, about 11 hours, about 12 hours, about 13 hours, about 14 hours, about 15 hours, about 16 hours, about 17 hours, about 18 hours, about 19 hours, about 20 hours, about 21 hours, about 22 hours, about 23 hours, about 1 day after the second immunogenic composition. Typically, the first immunogenic composition and the second immunogenic composition are administered simultaneously (i.e., within 15 minutes of each other). In an embodiment, the first immunogenic composition is administered intramuscularly. In an embodiment, the second immunogenic composition is administered intramuscularly. In an embodiment, the second immunogenic composition is administered intranasally. In an embodiment, the first immunogenic composition is administered intramuscularly and the second immunogenic composition is administered intramuscularly.In an embodiment, the first immunogenic composition is administered intramuscularly and the second immunogenic composition is administered intranasally.In an embodiment, the first immunogenic composition and the second immunogenic composition are administered intramuscularly in the same arm. In an embodiment, the first immunogenic composition and the second immunogenic composition are administered intramuscularly in different arms.

[0298] In embodiments, the additional immunogenic composition comprises mRNA encoding the SARS-Cov-2 spike glycoprotein, plasmid DNA encoding the SARS-Cov-2 spike glycoprotein, a viral vector encoding the SARS-Cov-2 spike glycoprotein, or an inactivated SARS-CoV-2 virus.

[0299] In an embodiment, the additional immunogenic composition comprises an mRNA encoding a CoV S polypeptide. In an embodiment, the mRNA encodes a CoV S polypeptide comprising a proline substitution at positions 986 and 987 of SEQ ID NO:1. In an embodiment, the mRNA encodes a CoV S polypeptide comprising an intact furin cleavage site. In an embodiment, the mRNA encodes a CoV S polypeptide comprising a proline substitution at positions 986 and 987 of SEQ ID NO:1 and an intact furin cleavage site. In an embodiment, the mRNA encodes a CoV S polypeptide comprising a proline substitution at positions 986 and 987 of SEQ ID NO:1 and an inactive furin cleavage site. In an embodiment, the mRNA encodes a CoV S polypeptide having the amino acid sequence of SEQ ID NO:87. In an embodiment, the mRNA encoding a CoV S polypeptide is encapsulated in a lipid nanoparticle. Exemplary immunogenic compositions comprising mRNA encoding a CoV S polypeptide are described in Jackson et al. N. Eng. J. Med. 2020, An mRNA Vaccine against SARS-CoV-2- preliminary report, which is incorporated herein by reference in its entirety. In embodiments, the composition comprising mRNA encoding a CoV S polypeptide is administered at a dose of 25 μg, 100 μg, or 250 μg.

[0300] In embodiments, the additional immunogenic composition comprises an adenoviral vector encoding a CoV S polypeptide. In embodiments, the AAV vector encodes a wild-type CoV S polypeptide. In embodiments, the AAV vector encodes a CoV S polypeptide comprising proline substitutions at positions 986 and 987 of SEQ ID NO:1 and an intact furin cleavage site. In embodiments, the AAV vector encodes a CoV S polypeptide comprising proline substitutions at positions 986 and 987 of SEQ ID NO:1 and an inactive furin cleavage site. In embodiments, the AAV vector encodes a CoV S polypeptide having the amino acid sequence of SEQ ID NO:87. The following publications describe immunogenic compositions comprising adenoviral vectors encoding CoV S polypeptides, each of which is incorporated by reference in its entirety: van Doremalen N. et al. A single dose of ChAdOx1 MERS provides protective immunity in rhesus macaques. Science Advances, 2020; van Doremalen N. et al. ChAdOx1 nCoV-19 vaccination prevents SARS-CoV-2 pneumonia in rhesus macaques. bioRxiv, (2020).

[0301] In an embodiment, the additional immunogenic composition comprises deoxyribonucleic acid (DNA). In an embodiment, the additional immunogenic composition comprises plasmid DNA. In an embodiment, the plasmid DNA encodes a CoV S polypeptide. In an embodiment, the DNA encodes a CoV S polypeptide comprising proline substitutions at positions 986 and 987 of SEQ ID NO:1 and an intact furin cleavage site. In an embodiment, the DNA encodes a CoV S polypeptide comprising proline substitutions at positions 986 and 987 of SEQ ID NO:1 and an inactive furin cleavage site. In an embodiment, the DNA encodes a CoV S polypeptide having the amino acid sequence of SEQ ID NO:87.

[0302] In embodiments, the additional immunogenic composition comprises an inactivated viral vaccine.

[0303] In embodiments, an immunogenic composition comprising CoV S polypeptide or nanoparticles, detergent-core nanoparticles, and HaSMaN is administered to a patient who has or has previously had an infection confirmed to be caused by SARS-CoV-2 or a heterogeneous SARS-CoV-2 strain. Infection with SARS-CoV-2 or a heterogeneous SARS-CoV-2 strain can be confirmed by a nucleic acid amplification test (e.g., polymerase chain reaction) or a serological test (e.g., a test for antibodies to SARS-CoV-2 viral antigens). In embodiments, a composition comprising CoV S polypeptide or nanoparticles, detergent-core nanoparticles, HaSMaN, or a combination thereof, is administered to a patient at least about 3 days, at least about 1 week, at least about 2 weeks, at least about 3 weeks, or at least about 4 weeks after the patient has been diagnosed with COVID-19. In embodiments, a composition comprising a CoV S polypeptide or nanoparticle, detergent-core nanoparticle, HaSMaN, or a combination thereof is administered to a patient between one week and one year after the patient's diagnosis of COVID-19, e.g., about one week, about two weeks, about three weeks, about four weeks, about five weeks, about six weeks, about one month, about two months, about three months, about four months, about five months, about six months, about seven months, about eight months, about nine months, about ten months, about eleven months, or about one year. In embodiments, a composition comprising a CoV S polypeptide or nanoparticle, detergent-core nanoparticle, HaSMaN, or a combination thereof is administered to a patient between 1 week and 20 years after the patient's diagnosis with COVID-19, e.g., about 1 week, about 2 weeks, about 3 weeks, about 4 weeks, about 5 weeks, about 6 weeks, about 1 month, about 2 months, about 3 months, about 4 months, about 5 months, about 6 months, about 7 months, about 8 months, about 9 months, about 10 months, about 11 months, about 1 year, about 2 years, about 3 years, about 4 years, about 5 years, about 6 years, about 7 years, about 8 years, about 9 years, about 10 years, about 11 years, about 12 years, about 13 years, about 14 years, about 15 years, about 16 years, about 17 years, about 18 years, about 19 years, or about 20 years.

[0304] In embodiments, a composition comprising a CoV S polypeptide or nanoparticle, detergent-core nanoparticle, HaSMaN, or a combination thereof is administered to a patient after administration of a first immunogenic composition. Non-limiting examples of the first immunogenic composition include SARS-CoV-2 spike glycoprotein, mRNA encoding SARS-Cov-2 spike glycoprotein, plasmid DNA encoding SARS-Cov-2 spike glycoprotein, viral vector encoding SARS-Cov-2 spike glycoprotein, or inactivated SARS-CoV-2 virus. In embodiments, the CoV S polypeptide or nanoparticles comprising same are administered for about 1 week to about 1 year, about 1 week to 1 month, about 3 weeks to 4 weeks, about 1 week to 5 years, about 1 year to about 5 years, about 1 year to about 3 years, about 3 years to about 5 years, about 5 years to about 10 years, about 1 year to about 10 years, or about 1 year to about 2 years after administration of the first immunogenic composition. In embodiments, the CoV S polypeptide or nanoparticles comprising same are administered for about 1 week to about 1 year after administration of the first immunogenic composition, for example, about 1 week, about 2 weeks, about 3 weeks, about 4 weeks, about 5 weeks, about 6 weeks, about 7 weeks, about 8 weeks, about 9 weeks, about 10 weeks, about 1 month, about 2 months, about 3 months, about 4 months, about 5 months, about 6 months, about 7 months, about 8 months, about 9 months, about 10 months, about 11 months, or about 1 year after administration of the first immunogenic composition.

[0305] In embodiments, compositions comprising CoV S polypeptides or nanoparticles comprising CoV S polypeptides, detergent-core nanoparticles, HaSMaN, or combinations thereof are useful for preparing immunogenic compositions for stimulating an immune response that confers immunity or substantial immunity to one or more of MERS, SARS, SARS-CoV-2, and heterogeneous SARS-CoV-2 strains. Both mucosal and cellular immunity can contribute to immunity to infection and disease. Antibodies secreted locally in the upper respiratory tract are a major factor in resistance to natural infection. Secretory immunoglobulin A (sIgA) is involved in protecting the upper respiratory tract, and serum IgG is involved in protecting the lower respiratory tract. The immune response elicited by infection protects against reinfection with the same virus or antigenically similar virus strains. Antibodies produced in a host following immunization with the nanoparticles disclosed herein can also be administered to another person, thereby providing passive administration in the subject.

[0306] In embodiments, a composition comprising a CoV S polypeptide or nanoparticle, detergent-core nanoparticle, HaSMaN, or a combination thereof induces cross-neutralizing antibodies against a SARS-CoV-2 virus that comprises an S protein having one or more modifications selected from the following: (a) a deletion of one or more amino acids in the NTD (the one or more amino acids are selected from the group consisting of amino acids 56, 57, 131, 132, 144, 145, 228, 229, 230, 231, 234, 235, 236, 237, 238, 239, 240, or a combination thereof); (b) a mutation in one or more amino acids of the NTD (the one or more mutations are selected from the group consisting of amino acids 5, 6, 7, 13, 39, 51, 53, 54, 56, 57, 62, 63, 67, 82, 125, 129, 131, 132, 133, 139, 143, 144, 145, 177, 200, 201, 202, 209, 229, 233, 240, 245, or a combination thereof); (c) one or more amino acid mutations in the RBD (the one or more amino acid mutations are selected from the group consisting of amino acids 333, 404, 419, 426, 439, 440, 464, 465, 471, 477, 481, 488, and combinations thereof); (d) a mutation of one or more amino acids in SD1 / 2 (the one or more amino acids are selected from the group consisting of 557, 600, 601, 642, 664, 668, and combinations thereof); (e) an inactive furin cleavage site (corresponding to one or more mutations in amino acids 669–672); (f) a deletion of one or more amino acids in the S2 subunit (the amino acids are selected from the group consisting of 676-685, 676-702, 702-711, 775-793, 806-815, and combinations thereof); (g) a mutation in one or more amino acids of the S2 subunit (the amino acids are selected from the group consisting of 688, 703, 846, 875, 937, 969, 973, 974, 1014, 1058, 1105, and 1163, and combinations thereof); (h) deletion of one or more amino acids from TMCT (amino acids 1201-1260); (The amino acids of the CoV S glycoprotein are numbered relative to SEQ ID NO:2).

[0307] In embodiments, a composition comprising a CoV S polypeptide or a nanoparticle comprising a CoV S polypeptide, detergent-core nanoparticle, HaSMaN, or a combination thereof induces cross-neutralizing antibodies against a SARS-CoV-2 virus comprising one or more modifications selected from a deletion of amino acid 56, a deletion of amino acid 57, a deletion of amino acid 131, N488Y, A557D,D601G, P668H, T703I, S969A, D1105H, N426K, and Y440F, wherein the amino acids are numbered relative to a CoV S polypeptide having the amino acid sequence of SEQ ID NO:2.

[0308] In embodiments, a composition comprising a CoV S polypeptide or a nanoparticle comprising a CoV S polypeptide, detergent-core nanoparticle, HaSMaN, or a combination thereof induces cross-neutralizing antibodies against a SARS-CoV-2 virus comprising one or more modifications selected from a deletion of amino acid 56, a deletion of amino acid 57, a deletion of amino acid 131, N488Y, A557D,D601G, P668H, T703I, S969A, and D1105H, where the amino acids are numbered relative to a CoV S polypeptide having the amino acid sequence of SEQ ID NO:2.

[0309] In embodiments, a composition comprising a CoV S polypeptide or a nanoparticle comprising a CoV S polypeptide, detergent-core nanoparticle, HaSMaN, or a combination thereof induces cross-neutralizing antibodies against a SARS-CoV-2 virus comprising an S protein having one or more modifications selected from the following: D67A, D202G, L229H, K404N, E471K, N488Y, D601G, and A688V (amino acids are numbered relative to a CoV S polypeptide having the amino acid sequence of SEQ ID NO:2).

[0310] In embodiments, a composition comprising a CoV S polypeptide or a nanoparticle comprising a CoV S polypeptide, detergent-core nanoparticle, HaSMaN, or a combination thereof induces cross-neutralizing antibodies against a SARS-CoCoV-2 virus comprising one or more modifications selected from a deletion of amino acids 229-231, D67A, D202G, K404N, E471K, N488Y, D601G, and A688V, where the amino acids are numbered relative to a CoV S polypeptide having the amino acid sequence of SEQ ID NO:2.

[0311] In embodiments, a composition comprising a CoV S polypeptide or a nanoparticle comprising a CoV S polypeptide, detergent-core nanoparticle, HaSMaN, or a combination thereof induces cross-neutralizing antibodies against a SARS-CoCoV-2 virus comprising one or more modifications selected from a deletion of amino acids 229-231, L5F, D67A, D202G, K404N, E471K, N488Y, D601G, and A688V, where the amino acids are numbered relative to a CoV S polypeptide having the amino acid sequence of SEQ ID NO:2.

[0312] In embodiments, a composition comprising a CoV S polypeptide or a nanoparticle comprising a CoV S polypeptide, detergent-core nanoparticle, HaSMaN, or a combination thereof induces cross-neutralizing antibodies against a SARS-CoV-2 virus comprising an S protein having one or more modifications selected from the following: L5F, T7N, P13S, D125Y, R177S, K404T, E471K, N488Y, D601G, H642Y, T1014I, and V1163F (amino acids are numbered relative to a CoV S polypeptide having the amino acid sequence of SEQ ID NO:2).

[0313] In embodiments, a composition comprising a CoV S polypeptide or nanoparticles comprising a CoV S polypeptide, detergent-core nanoparticles, HaSMaN, or a combination thereof induces cross-neutralizing antibodies against SARS-CoV-2 virus with an S protein comprising one or more modifications selected from W139C and L439R, the amino acids being numbered relative to the CoV S polypeptide having the amino acid sequence of SEQ ID NO: 2. In embodiments, a CoV S protein comprising W139C and L439R modifications is expressed with a signal peptide having the amino acid sequence of SEQ ID NO: 117 or SEQ ID NO: 5. In embodiments, a CoV S protein or nanoparticles comprising a CoV S protein induces cross-neutralizing antibodies against SARS-CoV-2 virus with one or more modifications selected from D601G, W139C, and L439R, the amino acids being numbered relative to the CoV S polypeptide having the amino acid sequence of SEQ ID NO: 2. In embodiments, the CoV S protein or nanoparticle containing the D601G, W139C, and L439R modifications is expressed with a signal peptide having the amino acid sequence of SEQ ID NO:117 or SEQ ID NO:5.

[0314] In embodiments, a composition comprising a CoV S polypeptide or a nanoparticle comprising a CoV S polypeptide, detergent-core nanoparticle, HaSMaN, or a combination thereof induces cross-neutralizing antibodies against SARS-CoV-2 virus having one or more modifications selected from D601G, L5F, D67A, D202G, amino acids 229-231, R233I, K404N, E471K, N488Y, and A688V, where the amino acids are numbered relative to a CoV S polypeptide having the amino acid sequence of SEQ ID NO:2. In embodiments, a composition comprising a CoV S polypeptide or nanoparticle, detergent-core nanoparticle, HaSMaN, or a combination thereof induces cross-neutralizing antibodies against a SARS-CoV-2 virus having one or more modifications selected from L5F, D67A, D202G, a deletion of amino acids 229-231, R233I, K404N, E471K, N488Y, and A688V, where the amino acids are numbered relative to a CoV S polypeptide having the amino acid sequence of SEQ ID NO:2.

[0315] In embodiments, a composition comprising a CoV S polypeptide or nanoparticles comprising a CoV S polypeptide, detergent-core nanoparticles, HaSMaN, or a combination thereof, is administered for up to about 1 month, up to about 2 months, up to about 2.5 months, up to about 3 months, up to about 3.5 months, up to about 4 months, up to about 4.5 months, up to about 5 months, up to about 5.5 months, up to about 6 months, up to about 6.5 months, up to about 7 months, up to about 7.5 months, up to about 8 months, up to about 8.5 months, up to about 9 months, up to about 9.5 months, up to about 10 months, up to about 10.5 months, up to about 11 months, up to about 11.5 months, up to about 12 months, up to about 1 month ... Up to about 12.5 months, Up to about 13 months, Up to about 13.5 months, Up to about 14 months, Up to about 14.5 months, Up to about 15 months, Up to about 15.5 months, Up to about 16 months, Up to about 16.5 months, Up to about 17 months, Up to about 17.5 months, Up to about 18 months, Up to about 18.5 months, Up to about 19 months, Up to about 19.5 months, Up to about 20 months, Up to about 20.5 months, Up to about 21 months, Up to about 21.5 months, Up to about 22 months, Up to about 22.5 months, Up to about 23 months, up to about 23.5 months, up to about 24 months, up to about 2.1 years, up to about 2.2 years, up to about 2.3 years, up to about 2.4 years, up to about 2.5 years, up to about 2.6 years, up to about 2.7 years, up to about 2.8 years, up to about 2.9 years, up to about 3 years or more, about 50% to about 99%, about 80% to about 99%, about 75% to about 99%, about 80% to about 95%, about 90% to about 98%, about 75% to about 95%, about 80% to about 90%, about 85% to about 95%, about 80% to about 95%, at least about 50 %, at least about 55%, at least about 60%, at least about 65%, at least about 70%, at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 91%, at least about 92%, at least about 93%, at least about 94%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, or at least about 99% of the SARS-CoV-2 virus or a heterogeneous SARS-CoV-2 strain (e.g., B.1.1.7 SARS-CoV-2 strain ... virus, B.1.1.7 SARS-CoV-2 virus, B.1.1.7 SARS-CoV-2 virus, B.1.1.7 SARS-CoV-2 virus, B.1.1.7 SAThe present invention has efficacy for preventing coronavirus disease 19 (COVID-19) from a patient infected with a pulmonary pulmonary sarcoma (P.351 SARS-CoV-2 strain, P.1 SARS-CoV-2 strain, B.1.617.2 SARS-CoV-2 strain, B.1.525 SARS-CoV-2 strain, B.1.526 SARS-CoV-2 strain, B.1.617.1 SARS-CoV-2 strain, C.37 SARS-CoV-2 strain, B.1.621 SARS-CoV-2 strain, B.1.1.529 SARS-CoV-2 strain, or Cal.20C SARS-CoV-2 strain). In an embodiment, the COVID-19 is mild COVID-19. In an embodiment, the COVID-19 is moderate COVID-19. In an embodiment, the COVID-19 is severe COVID-19. In an embodiment, the COVID-19 is asymptomatic COVID-19.

[0316] In embodiments, the present disclosure provides a method for producing one or more of high affinity anti-MERS-CoV, anti-SARS-CoV, anti-SARS-CoV-2, or anti-influenza virus antibodies. The high affinity antibodies produced by immunization with the nanoparticles disclosed herein are obtained by administering to an animal an immunogenic composition comprising a CoV S polypeptide or nanoparticle, detergent-core nanoparticle, HaSMaN, or a combination thereof, collecting serum and / or plasma from the animal, and purifying the antibodies from the serum and / or plasma. In one embodiment, the animal is a human. In an embodiment, the animal is a chicken, mouse, guinea pig, rat, rabbit, goat, human, horse, sheep, or cow. In one embodiment, the animal is a cow or horse. In another embodiment, the cow or horse animal is transgenic. In a further embodiment, the transgenic cow or horse animal produces human antibodies. In some embodiments, the animal produces monoclonal antibodies. In some embodiments, the animal produces polyclonal antibodies. In one embodiment, the method further comprises administration of an adjuvant or an immunostimulatory compound. In a further embodiment, the purified high affinity antibody is administered to a human subject. In one embodiment, the human subject is at risk for infection by one or more of MERS, SARS, SARS-CoV-2, and influenza viruses.

[0317] In some embodiments, the present disclosure provides a co-formulation (i.e., pre-filled syringe or pre-mix) strategy for immunogenic compositions including nanoparticles. The typical vaccine administration strategy currently utilized is a bedside mix formulation. That is, the vaccine composition and the adjuvant are stored separately and mixed before administration. Pre-mix, co-formulation or pre-filled syringe strategies for vaccines are less common due to concerns about the stability and subsequent immunogenicity potential of antigens (e.g., hemagglutinin and CoV S polypeptides). The present disclosure provides immunogenic compositions that can be pre-mixed and stored in advance. The disclosed vaccination strategies and formulations can improve vaccination efficiency and reduce the risk of bedside mixing errors while maintaining overall safety and immunogenicity.

[0318] A variety of containers can be used to store and transport the premix formulations, including syringes and plastic ampoules for single doses. In some cases, plastic ampoules can be manufactured using blow-fill-seal manufacturing techniques or methods. In general, the blow-fill-seal (BFS) manufacturing method involves extruding a plastic material (e.g., resin) to form a parison, which is then placed in a mold and cut to size. A filling needle or mandrel is then used to expand and inflate the plastic, resulting in a hollow ampoule that substantially conforms to the shape of the mold. Once expanded, a desired volume of liquid can be injected into the ampoule, the filling needle or mandrel can be removed, and the ampoule can be sealed. Thus, BFS can be an automated process that can be performed in a sterile environment without direct human intervention.

[0319] In some cases, the ability to aseptically produce sterile ampoules containing a desired liquid can make BFS produced ampoules particularly well suited for the pharmaceutical industry. However, BFS technology is not compatible with all drug solutions, products, etc. For example, some known BFS manufacturing methods involve feeding the liquid or product into the ampule while the plastic is still relatively hot, which can have an adverse effect on temperature sensitive liquids and / or products, such as vaccines, biologics, etc. However, advances in low temperature BFS technology have increased the variety of suitable products, liquids, etc., allowing some vaccines, biologics, and / or other temperature sensitive pharmaceutical products to be included in BFS ampoules.

[0320] In some cases, BFS ampoules can have a size, shape, and / or configuration based at least in part on a desired use and / or a desired drug fluid or dosage that the ampoules are configured to contain. For example, some known BFS ampoules can include a pierce top, a twist-off top, a top that includes a male or female luer, and / or the like. Some known BFS ampoules can have a size and / or shape based on a volume of fluid or dosage that is configured to be placed therein. Additionally, some known BFS ampoules can be manufactured in strips of multiple temporarily connected ampoules, which can increase manufacturing, packaging, and / or storage efficiency and / or the like.

[0321] In embodiments, the immunogenic compositions described herein are provided in a pre-filled syringe. When preparing the immunogenic composition in the pre-filled syringe, the antigen and adjuvant are combined prior to administration. In embodiments, the pre-filled syringe comprises a hemagglutinin and a CoV S polypeptide. In embodiments, the pre-filled syringe comprises a hemagglutinin and does not comprise a CoV S polypeptide. In embodiments, the pre-filled syringe comprises a CoV S polypeptide and does not comprise a hemagglutinin.

[0322] In embodiments, the subject is administered the immunogenic composition from a pre-filled syringe. In embodiments, the subject is administered an immunogenic composition comprising both hemagglutinin and a CoV S polypeptide in a single pre-filled syringe. In embodiments, the subject is administered the immunogenic composition from a pre-filled syringe comprising a CoV S polypeptide but not a hemagglutinin. In embodiments, the subject is administered the immunogenic composition from a pre-filled syringe comprising a hemagglutinin but not a CoV S polypeptide.

[0323] All patents, patent applications, references, and articles cited in this disclosure are expressly incorporated by reference in their entirety for all purposes. EXAMPLES

[0324] Example 1 Expression and purification of coronavirus spike (S) polypeptide nanoparticles Native coronavirus spike (S) polypeptides (SEQ ID NO:1 and SEQ ID NO:2) and CoV spike polypeptides having amino acid sequences corresponding to SEQ ID NOs:3, 4, 38, 41, 44, 48, 51, 54, 58, 61, 63, 65, 67, 73, 75, 78, 79, 82, 83, 85, 87, 106, 108, 89, 112-115, 132, 133, 114, 138, 141, 144, 147, 151, 153, 156, and 158 were expressed in a baculovirus expression system and recombinant plaques expressing coronavirus spike (S) polypeptides were picked and confirmed. In each case, the signal peptide is SEQ ID NO:5. Figures 2 and 4 show the successful purification of CoV spike polypeptides BV2364, BV2365, BV2366, BV2367, BV2368, BV2369, BV2373, BV2374, and BV2375. Table 2 shows the sequence characteristics of the aforementioned CoV spike polypeptides. [Table 10-1] [Table 10-2] [Table 10-3] [Table 10-4] [Table 10-5]

[0325] The wild-type BV2361 protein (SEQ ID NO: 2) binds to human angiotensin-converting enzyme 2 precursor (hACE2). Biolayer interferometry and ELISA were performed to assess binding of CoV S polypeptides.

[0326] Protein and nanoparticle production Recombinant viruses are amplified by infection of Sf9 insect cells. Cultures of insect cells are infected with baculovirus at approximately 3 MOI (multiplicity of infection = virus ffu or pfu / cell). Cultures and supernatants are harvested 48-72 hours post-infection. Approximately 30 mL of crude cell harvest is clarified by centrifugation at approximately 800 x g for 15 minutes. The resulting crude cell harvest, containing the coronavirus spike (S) protein, is purified as nanoparticles as follows:

[0327] To produce nanoparticles, the non-ionic detergent TERGITOL® nonylphenol ethoxylate NP-9 is used in the membrane protein extraction protocol. The crude extract is further purified by passing through anion exchange chromatography, lentil lectin affinity / HIC and cation exchange chromatography. Washed cells are lysed by detergent treatment and then subjected to a low pH treatment, which precipitates BV and Sf9 host cell DNA and proteins. The neutralized low qH-treated lysate is clarified and further purified by anion exchange and affinity chromatography before a second low qH treatment.

[0328] Affinity chromatography is used to enrich coronavirus spike (S) protein while removing Sf9 / BV proteins, DNA, and NP-9. Briefly, lentil lectin is a calcium- and manganese-containing metalloprotein that reversibly binds polysaccharides and glycosylated proteins containing glucose or mannose. The coronavirus spike (S) protein-containing anion exchange flow-through fraction is loaded onto a lentil lectin affinity chromatography resin (Capto Lentil Lectin, GE Healthcare). Glycosylated coronavirus spike (S) protein selectively binds to the resin, while non-glycosylated proteins and DNA are removed in the column flow-through. Weakly bound glycoproteins are removed by a buffer containing high salt and low molarity of methyl alpha-D-mannopyranoside (MMP).

[0329] The column wash is also used to detergent exchange the NP-9 detergent with polysorbate 80 (PS80) detergent. At high concentrations of MMP, coronavirus spike (S) polypeptides are eluted from the lentil lectin column in nanoparticle structures. After elution, coronavirus spike (S) protein trimers are assembled into nanoparticles composed of coronavirus spike (S) protein trimers and PS80 contained in a detergent core. The process described in this example can be used to express and purify any CoV S polypeptide nanoparticles described herein.

[0330] Example 2 Expression and purification of influenza detergent-core nanoparticles HA proteins from a single strain were expressed in Sf9 cells by baculovirus infection and grown for 48–96 h before harvest. HA proteins were then harvested by detergent extraction and purified into detergent-core nanoparticles. Briefly, a TMAE column was pre-equilibrated with a buffer consisting of 25 mM Tris (pH 8.0), 1.5 M sodium chloride, and 0.02% NP-9. Samples were loaded at ~90 cm / hr (24 min residence time) and then washed with EQ buffer (25 mM Tris, pH 8.0, 50 mM or 81 mM sodium chloride (for strains A and B, respectively), 0.02% NP-9). Purified samples were then eluted using 1.5 CV of EQ buffer.

[0331] For strain A, the product from the TMAE column was nanofiltered and subsequently loaded onto a lentil lectin affinity chromatography column pre-equilibrated with 3 CV (flow rate: 150 cm / h) of a buffer consisting of 25 mM Tris, 50 mM and 107 mM sodium chloride (for strain A and strain B, respectively), 0.02% (w / v) NP-9, pH 8.0. The sample was loaded with a residence time of 4 min. After loading, a wash was performed with 3 CV of lentil lectin equilibration buffer. The product was eluted with 25 mM sodium phosphate, pH 7.5, 200 mM sodium chloride, 500 mM methyl-α-D-mannopyranoside, 0.01% (w / v) PS80, pH 7.5, and 2 CV was collected at 75 cm / h and a residence time of 8 min.

[0332] For strain B, the TMAE column product was further purified using a Capto Blue column. The column was equilibrated with 25 mM Tris, pH 8.0, 107 mM sodium chloride, 0.02% (w / v) NP-9, and the TMAE product was then loaded at a flow rate of 225 cm / h with a residence time of 4 minutes and collected with 2 CV of equilibration buffer. The product from the Capto Blue column was nanofiltered and then loaded onto a lentil lectin affinity chromatography column pre-equilibrated with 3 CV (flow rate: 150 cm / h) of a buffer consisting of 25 mM Tris, 50 mM and 107 mM sodium chloride (for strains A and B, respectively), 0.02% (w / v) NP-9, pH 8.0. The sample was loaded with a residence time of 4 minutes. After loading, washing was performed with 3 CV of lentil lectin equilibration buffer. The product was eluted with 25 mM sodium phosphate, pH 7.5, 200 mM sodium chloride, 500 mM methyl-α-D-mannopyranoside, 0.01% (w / v) PS80, pH 7.5, 2 CV collected at 75 cm / hr and a retention time of 8 min.

[0333] The lentil lectin products for both strains A and B were concentrated to the target HA concentration and then buffer exchanged into the final drug substance formulation buffer. Concentration and buffer exchange were performed by ultrafiltration and diafiltration.

[0334] Example 3 Preparation of HaSMaN The detergent-core nanoparticles of Example 2 are mixed with saponin adjuvant (i.e., 85% by weight of Fraction A ISCOM matrix and 15% by weight of Fraction C ISCOM matrix) and incubated for at least 24 hours. Figure 7 (right panel) shows an electron microscope image of HaSMaN.

[0335] Example 4 Immunogenicity and efficacy of a combination vaccine against COVID-19 and influenza The immunogenicity and efficacy of a combination vaccine against COVID-19 and influenza (also called "qNIV / CoV2373") was evaluated. The combination vaccine included (i) a first vaccine (called "CoV2373") containing nanoparticles containing CoV S polypeptide (SEQ ID NO:87) and (ii) a second vaccine (called "qNIV") containing nanoparticles containing hemagglutinin (HA) from four different influenza strains. The nanoparticles containing influenza type A particles form HaSMaN. The nanoparticles containing influenza type A particles form detergent-core nanoparticles. The four different influenza strains are A / Kansas / 14 / 17, A / Brisbane / 02 / 016, B / Maryland / 15 / 16, and B / Phuket / 3073 / 13. The "standard" combination vaccine included 5 μg of CoV S polypeptide and 15 μg of HA per strain. The "high dose" combination vaccine contained 5 μg CoV S polypeptide and 60 μg HA per strain. The nanoparticles were premixed with a saponin adjuvant (i.e., 85% ISCOM matrix fraction A and 15% ISCOM matrix fraction C).

[0336] Groups of male and female animals were immunized with standard or high dose vaccines. Control groups were immunized with vaccines containing either (i) qNIV without CoV2373 (respective hemagglutinins present at 15 μg HA / strain), (ii) qNIV without CoV2373 (respective hemagglutinins present at 50 μg HA / strain), or (iii) qNIV without CoV2373 (5 μg CoV S polypeptide). All vaccines contained 50 μg saponin adjuvant (Figure 8A).

[0337] Human ACE2 receptor-blocking antibody levels produced by the combination vaccine were compared to animals immunized with qNIV alone or CoV2373 alone. Animals immunized with qNIV / CoV2373 had slightly elevated levels of hACE2 receptor-blocking antibodies 2 weeks after a single dose (GMT = 34–39), which increased 3.2–7.3-fold (GMT 107–202) 2 weeks after the booster immunization. Human ACE2 inhibitory titers were comparable to animals immunized with nanoparticles containing 5 μg CoV2373 (GMT = 290). Animals immunized with qNIV alone had no measurable hACE inhibitory antibodies (Figure 8B). Hemagglutination inhibition (HAI) antibody titers were compared between groups. HAI titers against influenza A and influenza B strains increased 2 weeks after a single dose and increased 2–7-fold 2 weeks after the booster immunization. HAI titers produced by the qNIV / CoV2373 combination were comparable to those produced by immunization with low or high doses of qNIV for all influenza A and B strains. Animals immunized with 5 μg of CoV2373 vaccine had no measurable HAI antibodies to strains A or B (Figure 8C-F).

[0338] Immunogenic qNIV / CoV2373 combination vaccine in hamsters The immunogenicity and protection produced by the qNIV / CoV2373 combination vaccine was then compared to a vaccine containing qNIV alone or CoV2373 alone in hamsters vaccinated with SARS-CoV-2. Groups of hamsters were immunized with qNIV / CoV2373, consisting of 10 μg or 2.5 μg HA / strain combined with 5 μg or 1 μg CoV2373. Comparator groups were immunized with qNIV (10 μg or 2.5 μg HA / strain) or CoV2373 (5 μg or 1 μg). All vaccine formulations were adjuvanted with 15 μg saponin adjuvant. The placebo group received the formulation buffer (Figure 9A). Animals receiving the qNIV / CoV2373 combination showed elevated anti-S IgG antibodies 2 weeks after the primary immunization (GMT = 9467-25,295), which increased 15- to 30-fold (GMT = 275,341-418,124) 2 weeks after the booster immunization (Figure 9B, Figure 9C). Anti-S IgG titers 2 weeks after the first and second doses of monovalent CoV2373 (GMT = 4576-43,632-302,967-523,143-302,967-523,143) were comparable to animals receiving the combined vaccine (Figure 9B, Figure 9C).

[0339] Human ACE2 receptor inhibiting antibody levels induced by the qNIV / CoV2373 combination compared to those induced by monovalent CoV2373. Hamsters immunized with qNIV / CoV2373 showed significantly increased antibody levels (IC 50 ) and blocked spike binding to the hACE2 receptor after a single dose (GMT = 57-136). Receptor inhibition titers increased 6.2-16.3-fold after booster immunization (GMT = 654-1086). Human ACE2 inhibition levels were similar to hamsters after a single immunization with CoV2373 (GMT = 24-230). Human ACE2 receptor inhibition titers increased 7.7-68-fold after booster immunization (GMT = 1636-1769) (Figure 9D, Figure 9E).

[0340] The immune responses against influenza A and B strains induced by qNIV / CoV2373 were compared to immunization with qNIV. Hamsters immunized with this combination vaccine had high HAI titers against A / Kansas H3N2 (GMT = 113-202) and A / Brisbane H1N1 (GMT = 143-226) after a single immunization. HAI titers against A / Kansas H3N2 increased 6.3-14.2-fold (GMT = 1280-1810) following a booster immunization, and HAI titers against A / Brisbane H1N1 increased 5.7-10-fold (GMT = 1280-1437) following a booster immunization (Figure 10A-D). Animals immunized with qNIV had HAI titers comparable to those against A strains. A / Kansas (GMT = 80-106) and A / Brisbane (GMT = 121-211) after a single immunization. After boosting, A / Kansas HAI titers increased 24-fold (GMT = 1940-2560) and A / Brisbane HAI titers increased 8-12.1-fold (GMT = 1470-1689). Animals immunized with the combination vaccine had elevated HAI titers to B / Phuket after the first immunization (GMT = 80-143), which increased 5-9-fold (GMT = 570-718) after the second immunization. Animals that received a single immunization with qNIV had comparable B / Phuket HAI titers (GMT = 735-844) after primary / boost immunizations (Figure 10E, F). Similarly, animals immunized twice with qNIV / CoV2373 had similar B / Maryland (GMT = 160-142) HAI titers, which were equivalent to those induced by immunization with qNIV (GMT = 106-242) (Figures S10G, S10H).

[0341] Virus-neutralizing antibody titers were comparable between hamster groups immunized with qNIV / CoV2373 compared with animals immunized with qNIV alone. Animals immunized with qNIV / CoV2373 as primary / boost immunized had high neutralizing titers against A / Kansas (GMT = 15,693 to 16,916) and A / Brisbane (GMT = 6992 to 10,507). Immunization with qNIV elicited similar neutralization titers against A / Kansas (GMT=13,625-19,314) and A / Brisbane (GMT=20,146-22,146) (Figure 11A-D). Similarly, animals immunized with qNIV / CoV2373 or qNIV had comparable levels of B strain neutralization titers (Figure 11E-H). Overall, these results show that the qNIV / CoV2373 combination vaccine is comparable in immunogenicity to qNIV and the monovalent CoV2373 control, indicating that there is no interference with the immune response when qNIV and CoV2373 are co-administered with the saponin adjuvant. Competitive polyclonal RBD antibodies against neutralizing mAbs

[0342] Polyclonal antibodies were induced in hamsters competitively with the prototype US-WA spike RBD neutralizing mAbs CR3022, NVX.322.3, and NVX.239.12 (Table 3) regardless of vaccination with monovalent CoV2373 or combination qNIV. Hamsters immunized with monovalent CoV2373 had significantly higher polyclonal antibodies competing against US-WA RBD mAbs when immunized with 5 μg vs. 1 μg of monovalent CoV2373 (Figure 12A-C). [Table 11]

[0343] Combination of qNIV with 1 μg or 5 μg of CoV2373 rS somewhat reduced the levels of competitive polyclonal antibodies measured against the US-WA RBD. A similar pattern of competitive polyclonal antibody responses against the B.1.351 variant was induced in hamsters immunized with monovalent CoV2373 and qNIV / CoV2373 combination vaccines. However, combination vaccines with monovalent CoV2373 or qNIV induced significant polyclonal antibodies that competed with CR3002 and NVX.322.3 (Figure 12D-E). NVX-239.12 did not bind to the B.1.351 variant RBD. Post-vaccination clinical signals

[0344] To evaluate the protective effect of the combination vaccine, immunized and placebo-treated hamsters were inoculated with SARS-CoV-2 by the intranasal route 21 days after the second immunization (day 35) by the intranasal route with SARS-CoV-2. All animals survived the post-inoculation phase until scheduled necropsy (7 dpi). Animal weights were monitored daily throughout the post-inoculation period. Animals receiving placebo or immunized with qNIV (2.5 μg or 10 μg of HA / strain) lost 12.5%–15% body weight at 7 dpi. In contrast, animals immunized with 1 μg or 5 μg of CoV2373 retained their body weight with a weight gain of 2.6%–5% at 7 dpi (Figure 13A). Animals immunized with qNIV / CoV2373 retained their weight with a weight gain of 2.5%–5% at 7 dpi, which was similar to the non-infected sham group (Figure 13B). Subgenomic viral mRNA in oral swabs, bronchoalveolar lavage fluid (BAL), and lung samples

[0345] To examine the efficacy of the qNIV / CoV2373 vaccine, viral loads in the upper and lower respiratory tract were determined using qRT-PCR designed to detect SARS-CoV-2 subgenomic (sg) SARS-CoV-2 nucleocapsid (N) RNA. Oral swabs were collected on days 2, 4, and 7 post-infection (dpi). The highest levels of sgRNA were detected with a median peak of 4.4 (range 2.7-5.1) log 10 RNA copies / mL ―1 Virus levels were observed in oral swabs from placebo-treated animals at 2 dpi. At 4 dpi, virus levels were 3.2 (range 2.9–4.2) log 10 RNA copies / mL -1 and 3.0log at 7dpi. 10 (range 1.7-3.7) RNA copies / mL ―1 Viral RNA levels were not significantly different in oral swabs from animals immunized with 10 μg or 2.5 μg HA / strain, and were 4.4–4.5 (range 3.9–4.9) log 10 RNA copies / mL ―1 The highest levels of sgRNAs were 3.2–3.4 (range 1.7–3.7) log 10 RNA copies / mL -1 , and at 7 dpi, 2.5 to 3.4 (1.7 to 3.9) log 10 RNA / mL ―1 Oral swabs from animals immunized with 5 μg or 1 μg of CoV2373 had detectable viral RNA at 2 dpi (2.9–3.6 log 10 Copies / mL ―1 ). Viral RNA was not detected in swabs from animals immunized with CoV2373 at 4 dpi or 7 dpi (Figure 13C). Viral RNA (3.2–3.5 log 10 RNA copies / mL ―1 ) was only detected in swabs 2 dpi in animals immunized with qNIV / CoV2373, and no replicating virus was detected at 4 dpi or 7 dpi (Figure 13D).

[0346] BAL lavage fluids were obtained at necropsy and analyzed for viral RNA. The placebo group and groups immunized with 10 μg or 2.5 μg HA per strain had the highest median viral RNA levels. Aspirates from the placebo group had a median of 5.6 (range 5.1-6.4) log 10 sgRNA copies / mL ―1 The viral load in BAL was also higher in animals immunized with 10 μg HA per strain, with a median of 5.6 (range 4.4–5.9) log 10 RNA copies / mL ―1 , with a median of 5.5 (range 3.6–6.0) log in animals immunized with 2.5 μg HA per strain. 10 RNA copies / mL ―1 Little or no viral RNA was detected in BAL samples from animals immunized with CoV2373 (1 μg or 5 μg) or the qNIV / CoV2373 combination (Figure 13E).

[0347] Lung tissue was collected at necropsy to assess viral load. Animals receiving placebo-treated lung homogenates and qNIV had the highest viral load: placebo median 7.1 (range 6.4–8.9) log 10 RNA copies / gram -1 10 μg HA per strain, 7.3 (range 6.7–7.8) log 10 RNA copies / gram -1 and 2.5 μg HA per strain, 6.7 (range 6.0–7.7) log 10 RNA copies / gram -1 Lung homogenates from animals immunized with CoV2373 or the qNIV / CoV2373 combination had little to no detectable virus (Figure 13F).

[0348] Macroscopic and microscopic observations: All animals survived until scheduled necropsy (study day 42). Lungs were harvested and weighed. Lung weights were significantly higher in placebo-treated or qNIV-immunized animals compared to animals immunized with CoV2373 or the qNIV / CoV2373 combination (p ≤ 0.003) (Figure 13G). Microscopic findings in the airways of placebo-treated and qNIV-immunized animals were identical and consisted of bronchoalveolar hyperplasia, mixed alveolar inflammation, perivascular inflammation with surrounding tissue edema, and rare syncytial cells. No notable findings were seen in the lungs of animals immunized with CoV2373 vaccine or qNIV / CoV2373 vaccine (Figure 14A-J). These results are consistent with high viral loads and pneumonia in placebo-treated animals and those that received qNIV, while the lungs of animals vaccinated with CoV2373 and qNIV / CoV2373 were normal and virus-free.

[0349] A further capability required for the success of a combination respiratory vaccine would be to provide cover in the face of inevitable viral evolution. RNA respiratory viruses are particularly prone to rapid evolution, often occurring under immune pressure from the host and under antigenic shifts from animal origins. Sars-CoV-2 viral evolution has occurred under immune pressure in South Africa, resulting in clear outbreaks in populations where a certain level of herd immunity had been established. In the context of seasonal influenza, viral evolution is a key challenge to effective immunization. Recently, multiple severe influenza seasons dominated by A(H3N2) have occurred amid repeated reports of insufficient vaccine efficacy in the field. This is likely caused by both antigenic mismatches arising from egg-based vaccines and the virus itself due to its rapid rate of antigenic evolution.

[0350] In this study, we demonstrate that the qNIV / CoV2373 vaccine combination elicited competitive polyclonal antibody responses against the US-WA as well as B.1.351 South African variant of SARS-CoV-2 spike protein RBD neutralizing epitopes. This study also demonstrated the potential for neutralizing epitopes shared between the US-WA and B.1.352 RBD and induced by the CoV2373 vaccine.

[0351] In the notable event of 2019-20, both the emergence and the rapid increase of novel coronaviruses and COVID-19 disease were seen concomitant with the near absence of seasonal influenza. At this time, it has been proposed that COVID-19 control measures may have led to a decline in seasonal influenza cases, while others have proposed ecological mechanisms. In both cases, past centuries have shown that influenza recirculates and its potential to cause disease and highly infectious and clinically significant SARS-CoV-2, as well as new variants, continue to evolve globally. Co-infection of influenza and SAR-CoV-2 has been described. Common clinical symptoms of COVID-19 include fever, chills, cough, and dyspnea, making influenza virus infection difficult to diagnose. A retrospective study of hospitalized patients with severe SARS-CoV-2 positive cases showed that 12% (64 of 544) were coinfected with influenza A (84%, 54 / 64) and influenza B (16%, 10 / 64). However, the clinical impact of influenza and SARS-CoV-2 coinfection is unknown.

[0352] The future need for seasonal influenza and the ongoing need for a SARS-CoV-2 vaccine, coupled with the logistics of immunization with twice-yearly vaccines, have driven the demand for a combination vaccine. Here, we describe a coformulated influenza and SARS-CoV-2 nanoparticle vaccine that offers broad protection against cocirculating seasonal influenza and COVID-19 viruses, with the potential to build on the broad protective response to address the challenges of emerging influenza strains and SARS-CoV-2 variants.

[0353] Materials and Methods: Viral stocks and receptors: Isolates of SARS-CoV-2 (strain 2019-nCoV / USA-WA1 / 2020) were obtained from the Centers for Disease Control and Prevention and stock viruses were prepared by passaging in Vero E6 cells. Virus stocks of A / Kansas / 14 / 17, A / Brisbane / 02 / 016, B / Maryland / 15 / 16, and B / Phuket / 3073 / 13 were provided by Novavax, Inc. (Gaithersburg, MD, USA). Histidine-tagged human ACE2 receptor was purchased from Sino Biologics (Beijing, CHN). Monoclonal antibody CR3022

[23] was obtained from Creative BioLabs (Shirley, NY, USA, catalog number MRO-1214LC). SARS-CoV-2 US-WA recombinant 6-histidine-tagged receptor binding domain (RBD) was provided by Novavax, Inc. (Gaithersburg, MD, USA). Histidine-tagged B.1.351 spike RBD was obtained from Sino Biologics (catalog number 40592-V08H85, Beijing, CHN).

[0354] NVX-CoV2373 spike (S) protein and recombinant hemagglutinin vaccine: The CoV2373 vaccine was constructed from the full-length wild-type SARS-CoV-2 S glycoprotein based on GenBank gene sequence MN908947 nucleotides 21563-25384. This native full-length S protein was modified by mutating the putative furin cleavage site located within the S1 / S2 cleavage domain (from 682-RRAR-685 to 682-QQAQ-685) to confer protease resistance. Two proline amino acid substitutions were inserted at K986P and V987P (2P) positions within the heptad repeat 1 (HR1) domain to stabilize SARS-CoV-2S in a preferred conformation.

[0355] This synthetic transgene was codon-optimized and engineered into a baculovirus vector for expression in Spodoptera frugiperda (Sf9) insect cells (GenScript, Piscataway, NJ, USA). The spike trimer (designated CoV2373) was detergent extracted from the plasma membrane using Tris buffer containing TERGITOL NP-9 detergent and clarified by centrifugation. The S-trimer was purified using TMAE anion exchange and lentil lectin affinity chromatography. Purified CoV2373 was formulated in 25 mM sodium phosphate (pH 7.2), 300 mM NaCl, and 0.02% (v / v) polysorbate.

[0356] Hemagglutinin (HA) nanoparticles: Cloning and expression of influenza virus A / Kansas / 14 / 17, A / Brisbane / 02 / 016, B / Maryland / 15 / 16, and B / Phuket / 3073 / 13 HA genes were codon-optimized for expression in Sf9 insect cells. Synthetic codon-optimized HA genes were cloned into pBac1 baculovirus transfer vector (Millipore Sigma, Billerica, MA, USA). pBac1 plasmid was transfected into Sf9 with Flash-bacGOLD bacmid (Oxford Expression Technology, Oxford UK) containing the Autographa californica polyhedrosis virus genome. Sf9 cell cultures were infected with recombinant baculovirus expressing the HA gene. Recombinant HA was purified as previously described.

[0357] Immunogenicity in Ferrets. Ferrets (n=30, 15 males, 15 females) were randomized into 5 groups. Animals were immunized intramuscularly with 15 or 60 μg HA / strain without or mixed with 5 μg CoV2373. A control group was immunized with 5 μg CoV2373. All vaccines were adjuvanted with 50 μg saponin adjuvant. All groups were immunized with a prime / boost regimen spaced 21 days apart. Sera were collected for analysis 21 days after the primary dose and 14 days after the boost.

[0358] Hamster immunogenicity and SARS-CoV-2 inoculation Hamsters (n=54, 27 males, 27 females) aged 6-9 weeks and weighing approximately 100 g were randomly divided into 10 groups (n=5-6 / group). Animals were immunized by intramuscular injection with 10 μg HA per strain combined with 5 μg or 1 μg CoV2373; 2.5 μg HA per strain combined with 5 μg or 1 μg CoV2373; 10 μg HA per strain; 2.5 μg HA per strain; 5 μg CoV2373; or 1 μg CoV2373. The vaccine was mixed with 15 μg saponin adjuvant on the day of injection. All groups were immunized with a primary / boost regimen spaced 14 days apart. The placebo group (n=5) received formulation buffer on days 0 and 14. The sham control group (n=5) was not immunized. Analyses were performed 14 days after the primary vaccination and 14 days after the booster vaccination.

[0359] SARS-CoV-2 intranasal inoculation: Three weeks after the second immunization (day 35), vaccinated and placebo animals were sedated with 80 mg / kg ketamine and 5 mg / kg xylazine in 20 μL of sterile phosphate-buffered saline (PBS) and administered 2.0 × 10 4 Patients were inoculated with pfu of SARS-CoV-2 (2019-nCoV / USA-WA1 / 2020 strain) via the intranasal route.

[0360] Anti-spike IgG ELISA: A spike protein ELISA was used to determine anti-SARS-CoV-2 spike (S) protein IgG titers in serum. Microtiter plates (Thermo Fisher Scientific, Rochester, NY, USA) were filled with 1.0 μg / mL ―1 Plates were coated with 100% SARS-CoV-2 S protein (CoV2373, lot no. 16Apr20, Novavax, Inc. Gaithersburg, MD, USA). Plates washed with PBS-Tween (PBS-T) were blocked for nonspecific binding with TBS Startblock blocking buffer (Thermo Fisher Scientific). Serum samples were serially diluted 3-fold starting from a 1:50 dilution and added to the coated plates, followed by incubation for 2 h at room temperature. After incubation, plates were washed with PBS-T and horseradish peroxidase (HRP)-conjugated goat anti-hamster IgG (Southern Biotech, Birmingham, AL, USA) was added for 1 h. Plates were washed with PBS-T and 3,3',5,5'-tetramethylbenzidine (TMB) peroxidase substrate (Sigma, St Louis, MO, USA) was added. The reaction was stopped with TMB stop solution (ScyTek Laboratories, Inc. Logan, UT). Plates were read at OD 450 nm using a SpectraMax Plus plate reader (Molecular Devices, Sunnyvale, CA, USA). EC50 values ​​were calculated by 4-parameter fitting using SoftMax Pro 6.5.1 GxP software. Anti-spike IgG titers for individual animals were determined and group geometric mean titers (GMTs) and 95% confidence intervals (±95%CI) plotted using GraphPad Prism 8 software. Titers below the assay lower limit of detection (LOD) of 50 (starting dilution) were reported and a value of "25" was assigned to this sample to calculate the group GMT.

[0361] Human ACE2 receptor blocking antibody ELISA: hACE2 receptor blocking antibody titers were determined by ELISA. Microtiter plates were filled with 1.0 μg / mL ―1 The wells were coated with 100 ng / mL of SARS-CoV-2 S protein (CoV2373, lot no. 02Apr20, Novavax, Inc., Gaithersburg, MD, USA) at 4°C overnight. Sera were serially diluted 2-fold starting at a dilution of 1:40, added to the coated wells, and incubated for 1 h at room temperature. After washing, 30 ng / mL ―1 of histidine-tagged hACE2 (Sino Biologics, Beijing, CN) was added to the wells for 1 h at room temperature. HRP-conjugated anti-histidine IgG was added and incubated for 1 h, followed by the addition of TMB substrate. Plates were read at OD450nm using a SpectraMax Plus plate reader (Molecular Devices, Sunnyvale, CA, USA) and data were analyzed with SoftMax Pro 6.5.1 GxP software. The % inhibition for each dilution of each sample was calculated using the following formula in the SoftMax Pro program: 100-[(MeanResults / ControlValue@PositiveControl)*100].

[0362] Plots of serum dilution versus % inhibition were generated and curve fitting was performed by 4-parameter logistic (4PL) curve fitting to the data. Serum antibody titers at 50% inhibition (IC50) of hACE2 against SARS-CoV-2 rS protein were determined with the SoftMax Pro program. GraphPad Prism 8 software was used to plot the hACE2 receptor inhibition titers of individual animals, group GMT ± 95% CI. Titers less than 40 (starting dilution) were reported for titers below the assay limit of detection (LOD) and a value of "20" was assigned to this sample to calculate the group GMT.

[0363] Biolayer Interferometry Competitive Binding Assay: Competitive binding biolayer interferometry (BLI) assays were performed using an Octet QK 384 instrument (ForteBio). BLI studies were performed by binding his6-tagged SARS-CoV-2 rS protein receptor binding domain (RBD) to a Ni-NTA biosensor chip. The assay consisted of 1) experimental serum samples (1:200), pre-immune (day 0) negative control, and pre-immune serum at 5 μg / mL ―1 1) loading a positive control sample prepared by spiking a spike-specific monoclonal antibody (mAb) of 5 μg / mL into the RBD biosensor chip; and 2) loading a competitive SARS-CoV-2 mAb (5 μg / mL ―1 ) onto the RBD biosensor chip and measuring binding or competition. Competition of rS RBD protein binding of serum polyclonal antibodies competing with mAb was measured. Data were analyzed using Octet Data Analysis HT10.0 software. Data were normalized to the percentage of binding and competition of placebo day 0 serum and rS RBD mAb. Competing antibody concentration in serum samples (μg / mL ―1 ) was calculated based on the percentage of polyclonal antibody competition and the concentration of competing mAb.

[0364] Hemagglutinin-inhibiting antibodies (HAI): HAI responses to influenza A / Brisbane / 02 / 2018 (H1N1), A / Kansas / 14 / 17 (H3N2), and B strains (B / Maryland / 15 / 16 and B / Phuket / 3073 / 13) were assessed using serum samples on days 14 and 28. A 0.75% suspension of human red blood cells (RBCs, Biological Specialty Corporation, Allentown, PA, USA) was prepared in Dulbecco's phosphate-buffered saline (DPBS). Serum samples were treated with receptor-destroying enzyme (RDE) from Vibrio cholerae (Denka Seiken, Stamford, TX, USA) overnight at 37°C to remove nonspecific red blood cell (RBC) hemagglutination activity. RDE was inactivated the following day by incubation at 56°C for 1 h. RDE-treated sera were serially diluted 2-fold in DPBS in 96-well, U-bottom plates (starting at 1:10, 25 μL) and incubated with standardized influenza virus concentrations (4 HA units in 25 μL) for 25 min. At the completion of incubation, a 0.75% suspension of human RBCs (50 μL) was added to each well and the plates were incubated at room temperature for 45 min. Hemagglutination inhibition (HAI) was determined by observing the shape of the O-ring formed by the RBCs in the sample and negative control wells. HAI titers were recorded as the reciprocal of the highest serum dilution at which HAI was observed (last well with an O-ring). Titers less than 10 (starting dilution) were reported for titers below the assay limit of detection (LOD) and a value of "5" was assigned to this sample to calculate group geometric mean titers (GMT).

[0365] Microneutralization (MN) assay: Virus neutralizing antibodies against A / Kansas / 14 / 17 (H3N2), A / Brisbane / 02 / 208 H1N, B / Phuket / 3073 / 13, and B / Maryland / 15 / 2016 were assessed using serum samples from days 14 and 28. Serum samples were heat inactivated at 56°C for 30 min, serially diluted 2-fold (1:20, starting in 50 μL), and incubated with 100 TCID50 virus (50 μL) for 2 h. At the end of incubation, 100 μL of 1.5 × 10 5 / mL ―1 MDCK cells were added to each well, and the plates were incubated with 5% CO2 at 37 °C for influenza A virus and 32 °C for influenza B virus. After 18–22 h of incubation, cells were fixed with 80% cold acetone and incubated with mouse monoclonal anti-influenza A or B nucleoprotein (Millipore Billerica, MA, USA), followed by incubation with peroxidase-conjugated goat anti-mouse IgG (Kirkegaard and Perry Laboratories, Gaithersburg, MD, USA). The optical density after development with 3-amino-9-ethylcarbazole (AEC) substrate (Sigma Aldrich, Saint Louis, MO, USA) was used to calculate the 50% microneutralization titer (50% MN) of each serum sample. Titers less than 20 (starting dilution) were reported for titers below the assay limit of detection (LOD), and a value of "10" was assigned to this sample to calculate the group geometric mean titer (GMT).

[0366] Collection of oral swabs, bronchoalveolar lavage fluid (BAL), and lung tissue samples: Oral swabs were collected on study days 37, 39, and 42 (2, 4, and 7 dpi). BAL samples and lungs were collected at necropsy performed at 7 dpi. Lungs were weighed and divided in half, and one set was weighed (approximately 0.1-0.2 grams) and snap frozen for viral titer determination. The second set was preserved in formalin for histopathological analysis. For viral load assays, tissues were weighed, placed in pre-labeled Sarstedt cryovials (2 / sample), and snap frozen on dry ice. Lung homogenates were prepared in 0.5 mL of RNA-Stat using a handheld tissue homogenizer (Omni International, Kennesaw, GA, USA) for approximately 20 seconds. These samples were clarified by centrifugation, and the supernatant was isolated for viral load determination.

[0367] Quantification of subgenomic (sg) RNA by qRT-PCR: The qRT-PCR assay utilized primers and probes designed to amplify and bind to a conserved region of the coronavirus nucleocapsid (N) gene. The signal was compared to a standard curve to calculate copy numbers per mL. For the qRT-PCR assay, viral RNA was extracted from lung homogenates with RNA-STAT 60 (Tel-test "B") mixed with chloroform, precipitated, and suspended in RNase-free 0.04% NaN3 (AVE) buffer (QIAGEN catalog number 1020953). To generate controls for the amplification reactions, RNA was isolated from virus stocks using the same procedure. The amount of viral RNA was determined by comparison to a plasmid control with a known amount. 10 per 3 μL of final dilution was used. 8A copy of each was split into 10 μL single-use aliquots and stored at -80°C. A master mix was prepared using 2.5 mL of 2x buffer with Taq-polymerase prepared from the TaqMan RT-PCR kit (Biolin #BIO-78005). 50 μL of RT and 100 μL of RNAse inhibitor from the kit were added. Primer pairs at a concentration of 2 μM were added in a volume of 1.5 mL. 0.5 mL of water and 350 μL of probe at a concentration of 2 μM were added and the tube was vortexed. For the reaction, 45 μL of master mix and 5 μL of sample RNA are added in triplicate to wells of a 96-well plate.

[0368] For the generation of the control curve, control viral RNA was added at 10 6 ~10 7 Ten-fold serial dilutions of control RNA were prepared in RNAse-free water by adding 5 μL of control to 45 μL of water, and repeating this for seven dilutions. The standard curve range was 1-10 7 The number of copies of RNA per mL was calculated by extrapolating from the standard curve and multiplying by the reciprocal of the 0.2 ml extraction volume. For nasal washes, 50–5×10 copies were calculated by ... 8 The lung viral load was reported as RNA copies per gram of homogenate. The primer and probe sequences used in this study are shown below:

[0369] 2019-nCoV_N1-F: 5'-GAC CCC AAA ATC AGC GAA AT-3' (SEQ ID NO: 169)

[0370] 2019-nCoV_N1-R: 5'-TCT GGT TAC TGC CAG TTG AAT CTG-3' (SEQ ID NO: 170)

[0371] 2019-nCoV_N1-P: 5'-6-FAM / ACCCCGCAT / ZEN / TACGTTTGGTGGACC / 3IABkFQ (SEQ ID NO: 171)

[0372] Sg-NF 5'-CGATCTCTTGTAGATCTGTTCTC-3' (SEQ ID NO: 172)

[0373] Sg-NR 5'-GGTGAACCAAGACGCAG...

Claims

1. (a) an immunogenic composition comprising: (a) Coronavirus S (CoV S) glycoprotein in the form of detergent-core nanoparticles. a detergent, the detergent being a non-ionic detergent; (b) at least three hemagglutinin (HA) glycoproteins, each HA glycoprotein being from a different influenza strain; and (c) a pharma- ceutically acceptable buffer; and The immunogenic composition comprising:

2. The at least three HA glycoproteins are (a) detergent-core nanoparticles containing hemagglutinin (HA); (b) HaSMaN (hemagglutinin saponin matrix nanoparticles); (c) inactivated whole influenza virus; (d) a hemagglutinin composition extracted from an influenza virus, optionally an influenza split virion composition or a subunit influenza composition; and any combination thereof.

3. 3. The immunogenic composition of claim 2, wherein at least one HA glycoprotein is in the form of a detergent-core nanoparticle comprising HA, and at least one HA glycoprotein is in the form of HaSMaN.

4. The immunogenic composition of claim 3, wherein the hemagglutinin glycoprotein of the detergent-core nanoparticle is from an influenza B strain.

5. 4. The immunogenic composition of claim 3, wherein the hemagglutinin glycoprotein of the detergent-core nanoparticle is from an influenza A strain.

6. The immunogenic composition of claim 3, wherein the detergent-core nanoparticles are trypsin-resistant nanoparticles.

7. The immunogenic composition of claim 3, wherein the HaSMaN is a trypsin-resistant nanoparticle.

8. The immunogenic composition of any one of claims 1 to 7, wherein each HA glycoprotein is derived from a different influenza strain.

9. The immunogenic composition of any one of claims 1 to 7, comprising up to 4, up to 5, up to 6, up to 7, up to 8, up to 9, or up to 10 HA glycoproteins.

10. The immunogenic composition according to any one of claims 1 to 7, wherein each HA glycoprotein is in the form of a nanoparticle.

11. The immunogenic composition of claim 10, wherein each nanoparticle comprises HA glycoprotein from a single influenza strain.

12. The immunogenic composition of claim 11, wherein each nanoparticle is a detergent-core nanoparticle or HaSMaN.

13. The immunogenic composition according to any one of claims 1 to 7, comprising an adjuvant.

14. The immunogenic composition of claim 13, wherein the adjuvant is a saponin adjuvant.

15. the adjuvant comprises at least two ISCOM particles; the first ISCOM particles comprise Quillaja Saponaria Molina Fraction A and no Quillaja Saponaria Molina Fraction C; the second ISCOM particles comprise Quillaja Saponaria Molina Fraction C and no Quillaja Saponaria Molina Fraction A; The immunogenic composition of claim 14.

16. The immunogenic composition according to claim 15, wherein the fraction A of Quillaja Saponaria Molina accounts for 50 to 96% by weight of the total weight of the fraction A of Quillaja Saponaria Molina and the fraction C of Quillaja Saponaria Molina in the adjuvant, and the fraction C of Quillaja Saponaria Molina accounts for the remainder.

17. The immunogenic composition of claim 15, wherein Fraction A of Quillaja Saponaria Molina and Fraction C of Quillaja Saponaria Molina account for about 85% by weight and about 15% by weight, respectively, of the total weight of Fraction A of Quillaja Saponaria Molina and Fraction C of Quillaja Saponaria Molina in the adjuvant.

18. 14. The immunogenic composition of claim 13, comprising about 50 μg or about 75 μg of saponin adjuvant.

19. The immunogenic composition according to any one of claims 1 to 7, wherein the detergent is PS80.

20. 8. The immunogenic composition of any one of claims 1 to 7, wherein the influenza strain is of a subtype selected from the group consisting of H1, H2, H3, H4, H5, H6, H7, H8, H9, H10, H11, H12, H13, H14, H15, H16, H17, and H18.

21. 8. The immunogenic composition of any one of claims 1 to 7, wherein the pharma- ceutically acceptable buffer comprises: (i) about 25 mM sodium phosphate; (ii) about 150 mM sodium chloride; (iii) about 100 mM arginine hydrochloride; and (iv) about 5% trehalose, and the pH of the composition is about 7.

5.

22. The CoV S glycoprotein is (i) an S1 subunit having an inactivated furin cleavage site, the S1 subunit comprising an N-terminal domain (NTD), a receptor binding domain (RBD), subdomains 1 and 2 (SD1 / 2), and the inactivated furin cleavage site having the amino acid sequence of QQAQ (SEQ ID NO: 7); The NTD optionally comprises: (a) a deletion of one or more amino acids selected from the group consisting of amino acids 56, 57, 131, 132, 144, 145, 228, 229, 230, 231, 234, 235, 236, 237, 238, 239, 240, and combinations thereof; (b) an insertion of 1, 2, 3, or 4 amino acids after amino acid 132; (c) one or more amino acid mutations selected from the group consisting of amino acids 5, 6, 7, 13, 51, 53, 56, 57, 62, 63, 67, 82, 125, 129, 131, 132, 133, 139, 143, 144, 145, 177, 200, 201, 202, 209, 229, 233, 240, 245, and combinations thereof; comprising one or more modifications selected from the group consisting of: the RBD optionally comprises one or more amino acid mutations selected from the group consisting of amino acids 333, 404, 419, 426, 439, 440, 464, 465, 471, 477, 481, 488, and combinations thereof; the SD1 / 2 domain optionally comprises one or more amino acid mutations selected from the group consisting of 557, 600, 601, 642, 664, 668, and combinations thereof; (ii) the S2 subunit (amino acids 973 and 974 are prolines); The S2 subunit optionally comprises: (a) a deletion of one or more amino acids from 676-685, 676-702, 702-711, 775-793, 806-815, and combinations thereof; (b) one or more amino acid mutations from 688, 703, 846, 875, 937, 969, 1014, 1058, 1105, and 1163, and combinations thereof; (c) a deletion of one or more amino acids from the TMCT; and wherein the amino acids of the CoV S glycoprotein are numbered relative to the polypeptide having the sequence of SEQ ID NO:

2.

23. 23. The immunogenic composition of claim 22, wherein the CoV S glycoprotein comprises or consists of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% identity to any one of SEQ ID NOs: 86-89, 105, 106, 112-115, and 164-168.

24. 24. The immunogenic composition of claim 23, wherein the CoV S glycoprotein comprises a sequence that is at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% identical to SEQ ID NO:

87.

25. The immunogenic composition of any one of claims 1 to 7, comprising from about 1 µg to about 50 µg of CoV S glycoprotein and from about 5 µg to about 60 µg of hemagglutinin per strain.

26. 26. The immunogenic composition of claim 25, comprising about 20 μg to about 50 μg of CoV S glycoprotein and about 24 μg to about 40 μg of hemagglutinin per strain.

27. The immunogenic composition of any one of claims 1 to 7, comprising about 3 μg, about 5 μg, about 25 μg, about 22.5 μg, about 7.5 μg, or about 2.5 μg of coronavirus S glycoprotein.

28. 8. The immunogenic composition of any one of claims 1 to 7, comprising about 5 μg, about 10 μg, about 24 μg, about 25 μg, about 26 μg, about 27 μg, about 28 μg, about 29 μg, about 30 μg, about 31 μg, about 32 μg, about 33 μg, about 34 μg, about 35 μg, about 36 μg, about 37 μg, about 38 μg, about 39 μg, about 40 μg, or about 60 μg of hemagglutinin per strain.

29. A product for stimulating an immune response in a subject against SARS-CoV-2, a heterogeneous SARS-CoV-2 strain, influenza virus, or a combination thereof, comprising the immunogenic composition of any one of claims 1 to 7.

30. 30. The product of claim 29, wherein the immunogenic composition is administered as an initial dose on day 0 and as a booster dose on day 56.

31. 30. The product of claim 29, wherein the immunogenic composition is administered intramuscularly.

32. 30. The product of claim 29, wherein a single dose of the immunogenic composition is administered.

33. 30. The product of claim 29, wherein the heterogeneous SARS-CoV-2 strain is selected from the group consisting of Cal. 20C SARS-CoV-2 strain, P. 1 SARS-CoV-2 strain, B. 1.351 SARS-CoV-2 strain, B. 1.1.7 SARS-CoV-2 strain, SARS-CoV-2 B. 1.617.2 strain, B. 1.525 strain, B. 1.526 strain, B. 1.617.1 strain, C. 37 strain, B. 1.621 strain, or SARS-CoV-2 Omicron strain.

34. the efficacy of the immunogenic composition for preventing coronavirus disease 19 (COVID-19) is up to about 2 months, up to about 2.5 months, up to about 3 months, up to about 3.5 months, up to about 4 months, up to about 4.5 months, up to about 5 months, up to about 5.5 months, up to about 6 months, up to about 6.5 months, up to about 7 months, up to about 7.5 months, up to about 8 months, up to about 8.5 months, up to about 9 months, up to about 9.5 months, up to about 10 months, up to about 10.5 months, up to about 11 months, up to about 11.5 months, 30. The product of claim 29, wherein the affinity of the product is at least 50%, at least about 55%, at least about 60%, at least about 65%, at least about 70%, at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 91%, at least about 92%, at least about 93%, at least about 94%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, or at least about 99%, or about 100% for up to about 12 months.

35. The immunogenic composition for preventing coronavirus disease 19 (COVID-19) Effectiveness, about 50% to about 99%, about 50% for up to about 2 months, up to about 2.5 months, up to about 3 months, up to about 3.5 months, up to about 4 months, up to about 4.5 months, up to about 5 months, up to about 5.5 months, up to about 6 months, up to about 6.5 months, up to about 7 months, up to about 7.5 months, up to about 8 months, up to about 8.5 months, up to about 9 months, up to about 9.5 months, up to about 10 months, up to about 10.5 months, up to about 11 months, up to about 11.5 months, or up to about 12 months after administration of the immunogenic composition 30. The product of claim 29, wherein the solubility is from about 95%, about 50% to about 90%, about 50% to about 85%, about 50% to about 80%, about 60% to about 99%, about 60% to about 95%, about 60% to about 90%, about 60% to about 85%, about 60% to about 80%, about 40% to about 99%, about 40% to about 95%, about 40% to about 90%, about 40% to about 85%, about 40% to about 80%, about 40% to about 75%, about 40% to about 70%, about 40% to about 65%, about 40% to about 55%, or about 40% to about 50%.

36. A pre-filled syringe comprising the immunogenic composition of any one of claims 1 to 7.

Images