Methods for eliciting an immune response by administering a population of polymersomes with an associated antigen together with a population of polymersomes with an associated adjuvant, and compositions comprising the two polymersome populations

Abstract

The present invention relates to a method of inducing an immune response in a subject by administration of an antigen and an adjuvant, wherein the antigen is associated with a first population of polymersomes and the adjuvant is associated with a second population of polymersomes, and the two polymersome populations are administered to the subject. The present invention also relates to compositions, such as vaccines, comprising two polymersome populations of the invention, and to a method of inducing an immune response, or a method for treating, ameliorating, preventing, or diagnosing cancer, an autoimmune disease, or an infectious disease, comprising the step of providing a polymersome of the invention. TIFF2022543038000015.tif82153

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of priority to European Patent Application No. 19189549.9, filed August 1, 2019, and European Patent Application No. 20171327.8, filed April 24, 2020, the contents of which are incorporated herein by reference in their entireties for all purposes.

[0002] Sequence Listing This application contains a Sequence Listing in computer readable format, which is incorporated herein by reference.

[0003] Technical Field The present invention relates to a method of inducing an immune response by administering an antigen and an adjuvant, where the antigen is associated with a first population of polymersomes and the adjuvant is associated with a second population of polymersomes, and the two polymersome populations are administered to a subject. The present invention also relates to compositions comprising such two polymersome populations and therapeutic uses of such two polymersome populations. The antigen can be any antigen capable of inducing an immune response, for example a polypeptide, a carbohydrate, a polynucleotide, and combinations thereof. [Background technology]

[0004] 2. Background of the Invention Immunization is a well-established process, but different immunogens or antigens induce different responses. For example, membrane proteins form one class of antigens that generate low-level responses, which means that a large amount of membrane protein is required to generate or induce an immune response to the desired level. Membrane proteins are notoriously difficult to synthesize and are insoluble in water in the absence of detergents. Therefore, membrane proteins are expensive and it is difficult to obtain sufficient amounts of membrane proteins for immunization. Furthermore, membrane proteins require proper folding to function properly. The immunogenicity of correctly folded native membrane proteins is usually much better than their soluble forms, which may not be folded in a physiologically meaningful way. Therefore, even if adjuvants can be used to boost the immunogenicity of such soluble antigens, it is an inefficient method without much advantage (e.g., WO2014 / 077781A1).

[0005] To increase the chances of isolating antibodies that may be efficient in vivo, transfected cell and lipid-based systems have been used to present membrane protein antigens, but these systems are often unstable (e.g., oxidation sensitive), laborious, and costly. Moreover, for such membrane protein antigens, the current state of the art is to use inactive virus-like particles for immunization.

[0006] On the other hand, vaccines are the most efficient way to prevent diseases, mainly infectious diseases [e.g., Liu et al., 2016]. At present, the majority of licensed vaccines are made of either live or killed viruses. Although such vaccines are effective in generating humoral immunity (antibody-mediated responses) with the aim of preventing viral transmission and cell entry, concerns remain regarding the safety of such vaccines. In the past decades, scientific advances have helped to overcome such issues by engineering vaccine vectors that are non-replicating recombinant viruses. In parallel, protein-based or subunit antigens have been explored as a safer alternative. However, the immunity (both humoral and cellular responses) induced by such protein-based vaccines is typically insufficient. Several approaches have been used to improve the immunogenic properties of antigens. For example, microencapsulation of antigens in polymers has been extensively studied, which could enhance immunogenicity, but antigen aggregation and denaturation remain unsolved [e.g., Hilbert et al., 1999]. Furthermore, adjuvants (e.g., oil-in-water emulsions or polymer emulsions) [e.g., US9636397B2, US2015 / 0044242A1] are used together with antigens to induce more pronounced humoral and cellular responses. Despite these advances, they have low uptake and cross-presentation efficiency. Based on available information of the immune system upon infection with viruses, virus-like particles have been developed to mimic such properties to promote cross-presentation. Synthetic architectures such as liposomes in which antigens are encapsulated are particularly attractive. Liposomes are self-assembled monolayer structures made of lipids, and cationic liposomes are more attractive and promising as delivery vehicles because they are efficiently taken up by antigen-presenting cells (APCs) [e.g., Maji et al., 2016].Furthermore, liposomes can also be loaded with immunomodulators, such as monophosphoryl lipid A (MPL), CpG oligodeoxynucleotides, etc., which are toll-like receptor (TLR) agonists that stimulate immune cells via their receptors. Despite these favorable conditions for such delivery vehicles, one of the limiting factors is the stability of liposomes in the presence of serum components. The stability issue of liposomes can be somewhat reduced by PEGylation and loading of high melting point lipids. One such well-characterized example is the interbilayered-crosslinked multilamellar vesicle (ICMV), which is formed by stabilizing multilamellar vesicles with short covalent bridges linking lipids [e.g., Moon et al., 2011]. Other nanoparticle architectures have also led to successful immunization using nanodiscs [e.g., Kuai et al., 2017] or pH-sensitive particles [e.g., Luo et al., 2017]. However, such strategies still require adjuvants or are not very efficient outside the prototypic ovalbumin (OVA) model.

[0007] In addition, polymersomes have been provided as a stable alternative to liposomes and have been used to incorporate membrane proteins to induce immune responses [e.g. Quer et al., 2011, WO2014 / 077781A1]. Protein antigens have also been encapsulated in the chemically modified (but oxidation-sensitive) membrane of polymersomes to deliver antigens and adjuvants to dendritic cells [e.g. Stano et al., 2013].

[0008] Even with this progress made through the use of polymers, there remains a need to provide alternative methods of eliciting an immune response, especially for the treatment and / or prevention of infectious diseases, cancer and autoimmune diseases. Summary of the Invention

[0009] The present invention relates to a method of eliciting an immune response in a subject by administration of an antigen and an adjuvant, where the antigen is associated with a first population of polymersomes and the adjuvant is associated with a second population of polymersomes, and the two polymersome populations are administered to the subject.

[0010] In such methods, the antigen may be associated with the first population of polymersomes by encapsulation of the antigen within the first population of polymersomes, by incorporation of the antigen into the surrounding membrane of the polymersomes of the first population of polymersomes, by conjugation of the antigen to the outer surface of the polymersomes by covalent bonds, and / or by conjugation of the antigen to the outer surface of the polymersomes by non-covalent bonds.

[0011] In such methods, the adjuvant may also be associated with the second population of polymersomes by encapsulation of the adjuvant within the second population of polymersomes, by incorporation of the adjuvant into the surrounding membrane of the polymersomes of the second population of polymersomes, by conjugation of the adjuvant to the outer surface of the polymersomes by covalent bonds, and / or by conjugation of the adjuvant to the outer surface of the polymersomes by non-covalent bonds.

[0012] In aspects of the method, the antigen may be selected from the group consisting of a polypeptide, a carbohydrate, a polynucleotide, and combinations thereof.

[0013] The present invention further relates to a method for producing the two polymersome populations.The present invention further relates to a composition comprising the two polymersome populations of the present invention, isolated antigen presenting cells and hybridoma cells exposed to the polymersomes or compositions of the present invention.The present invention also relates to a vaccine comprising the two polymersome populations of the present invention, a method for inducing an immune response or a method for treating, ameliorating, preventing or diagnosing cancer, an autoimmune disease or an infectious disease comprising providing a polymersome of the present invention to a subject in need thereof.

[0014] The present invention provides two polymersome populations, where at least one or both of the polymersome populations have an average diameter of about 120 nm or more or 140 nm or more, the populations of polymersomes having an antigen or adjuvant associated with the polymersomes, such as an encapsulated soluble antigen or adjuvant, the antigen being (i) a polypeptide, (ii) carbohydrates, (iii) a polynucleotide, which is preferably not an antisense oligonucleotide, and more preferably is a DNA molecule or an mRNA molecule; (iv) lipids, or (v) Any combination of (i) to (iv) The present invention also relates to the use of two polymersome populations, which may be selected from the group consisting of:

[0015] The present invention also relates to the use of two polymersome populations to elicit an immune response, where at least one or both populations have an average polymersome diameter of about 120 nm or more or about 140 nm or more, and the polymersomes of the populations are associated with either an antigen, e.g., a soluble encapsulated antigen, or an adjuvant. (i) a polypeptide, (ii) carbohydrates, (iii) a polynucleotide, which is preferably not an antisense oligonucleotide, and more preferably is a DNA molecule or an mRNA molecule; (iv) lipids, or (v) Any combination of (i) to (iv) It may be selected from the group consisting of:

[0016] In an alternative aspect, the invention provides a method of eliciting an immune response in a subject by administration of an antigen and an adjuvant, where the antigen is associated with a first population of polymersomes and a second population of polymersomes acts as an adjuvant, and the two polymersome populations are administered to the subject.

[0017] In the present invention, it has been found that administration of two separate polymersome populations, one polymersome population associated with an antigen and the other polymersome population associated with only an adjuvant, leads to an increased immune response. Furthermore, by providing the polymersomes of the present invention, the encapsulated soluble (or solubilized) antigen generates a stronger humoral immune response (compared to free antigen with or without adjuvant) and increases the CD8 (+) It was found in the course of the present invention that it is possible to induce a T cell-mediated immune response. As a result, an increase in the efficiency of antibody production in the subject is achieved. The increase in efficiency can be obtained with or without the use of an adjuvant. Furthermore, it has been found that the polymersomes of the present invention are capable of inducing a CD8 T cell-mediated immune response. (+) The ability to induce T cell-mediated immune responses dramatically increases their potential as antigen delivery and presentation systems for immunotherapy.

[0018] Because soluble (e.g., solubilized) encapsulated antigens are presented by polymersomes, the use of polymersomes of the invention and antibodies produced by the methods of the invention will not only have a higher production success rate, higher affinity for their respective in vitro or in vivo targets, and correspondingly improved sensitivity when used in various solution-based antibody applications, but will also facilitate the generation of antibodies against difficult antigens that could not trigger antibody production using conventional methods using injection of free antigen, and / or reduce the amount of antigen required for such antibody production procedures, thereby reducing the cost of such production. Furthermore, the soluble (e.g., solubilized) encapsulated antigens presented by the polymersomes of the invention will be capable of binding to CD8 (+) They can also induce T cell-mediated immune responses, which extends the use of the corresponding polymersomes to cell-mediated immunity, thus improving their immunotherapeutic and antigen delivery and presentation capabilities.

[0019] [The present invention 1001] A method of inducing an immune response in a subject by administration of an antigen and an adjuvant, wherein the antigen is associated with a first population of polymersomes and the adjuvant is associated with a second population of polymersomes, and the two polymersome populations are administered to the subject. [The present invention 1002] (a) an antigen, Encapsulation of the antigen within the first population of polymersomes Incorporation of the antigen into the surrounding membrane of a polymersome in the first population of polymersomes, by conjugation of the antigen to the outer surface of the polymersome by covalent bonds; and / or By non-covalent conjugation of the antigen to the outer surface of the polymersome, associated with a first population of polymersomes; and / or (b) the adjuvant is Encapsulation of the adjuvant within the second population of polymersomes Incorporation of the adjuvant into the surrounding membrane of polymersomes in the second population of polymersomes, by conjugation of the adjuvant to the outer surface of the polymersome by covalent bonds, and / or By non-covalent conjugation of the adjuvant to the outer surface of the polymersome, associated with a second population of polymersomes, The method of the present invention 1001. [The present invention 1003] a first population of polymersomes having an antigen encapsulated within the polymersomes; a second population of polymersomes having an adjuvant encapsulated within the polymersomes; The method of the present invention 1002. [The present invention 1004] Any of the methods of the invention, wherein the two polymersome populations are administered by a route of administration selected from the group consisting of oral administration, intranasal administration, administration to a mucosal surface, inhalation, intradermal administration, intraperitoneal administration, subcutaneous administration, intravenous administration and intramuscular administration. [The present invention 1005] Any of the above methods of the invention, wherein the subject is a mammal, including a human, or a non-mammalian subject. [The present invention 1006] The method of the present invention 1005, wherein the subject is a mammal and is vaccinated against a disease selected from the group consisting of cancer, viral infection and bacterial infection, the subject is preferably a human and is preferably vaccinated against a coronavirus infection, the coronavirus being preferably MERS-CoV, SARS-CoV-2 or SARS-CoV-1. [The present invention 1007] (a) the subject is a non-mammalian animal and is to be vaccinated against a disease selected from the group consisting of a viral infection and a bacterial infection; or (b) the mammal is a goat, sheep, cow, or pig, the animal preferably comprising: (i) is a pig and is vaccinated against porcine epidemic diarrhea virus; or (ii) are ungulates and are vaccinated against FMD virus; The method of the present invention 1005. [The present invention 1008] Any of the preceding methods of the invention, wherein the encapsulated antigen is a soluble or solubilized antigen. [The present invention 1009] The antigen, preferably a soluble or solubilized encapsulated antigen, (i) a polypeptide, (ii) carbohydrates, (iii) a polynucleotide which is not an antisense oligonucleotide and is preferably a DNA molecule or an mRNA molecule; (iv) a combination of (i) and / or (ii) and / or (iii) Any of the methods of the present invention described above, selected from the group consisting of: [The present invention 1010] Any of the aforementioned methods of the invention, wherein the first and / or second population of polymersomes are oxidatively stable. [The present invention 1011] the encapsulated antigen comprises a soluble portion of a membrane protein (MP) or a membrane-associated peptide (MAP); Preferably, the antigen comprises a soluble portion of influenza hemagglutinin, swine influenza hemagglutinin, a spike protein, such as the porcine epidemic diarrhea virus spike protein, a spike protein of a human pathogenic coronavirus, such as the MERS-CoV spike protein, the SARS-CoV-2 spike protein, or the SARS-CoV-1 spike protein, ovalbumin (OVA), the B16 peptide, or the MC38 peptide, More preferably, the antigen comprises a polypeptide that is at least 60% or more (e.g., at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100%) identical to a polypeptide sequence selected from the group consisting of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:7, SEQ ID NO:8, SEQ ID NO:9, SEQ ID NO:10, SEQ ID NO:11, SEQ ID NO:12, SEQ ID NO:13, SEQ ID NO:14, SEQ ID NOs:43-46, SEQ ID NOs:34-41, SEQ ID NOs:48-51, and SEQ ID NO:65. Any of the methods of the present invention. [The present invention 1012] The first and / or second population of polymersomes have the following characteristics: (i) the first and / or second population of polymersomes comprises an oxidatively stable membrane; and / or (ii) the first and / or second population of polymersomes are synthetic; and / or (iii) the first and / or second population of polymersomes does not contain or is mixed with non-encapsulated antigen, and / or (iv) the first and / or second population of polymersomes comprises a membrane of an amphiphilic polymer; and / or (v) the first and / or second population of polymersomes comprises an amphiphilic synthetic block copolymer that forms a vesicle membrane; and / or (vi) the first and / or second population of polymersomes have a diameter of greater than 70 nm, preferably in the range of about 100 nm to about 1 μm, or about 100 nm to about 750 nm, or about 100 nm to about 500 nm, or about 125 nm to about 250 nm, about 140 nm to about 240 nm, about 150 nm to about 235 nm, about 170 nm to about 230 nm, or about 220 nm to about 180 nm, or about 190 nm to about 210 nm, and most preferably the diameter is about 200 nm; and / or (vii) the first and / or second population of polymersomes have the morphology of vesicles; (viii) the first and / or second population of polymersomes are self-assembling; (ix) the block copolymer or amphiphilic polymer is essentially non-immunogenic or essentially non-antigenic, preferably the block copolymer or amphiphilic polymer is non-immunogenic or non-antigenic; Any of the methods of the preceding invention, comprising one or more of: [The present invention 1013] The first and / or second population of polymersomes are Amphiphilic polymers comprising or consisting of diblock or triblock (ABA or ABC) copolymers Any of the preceding methods of the invention comprising or formed from [The present invention 1014] (a) the amphiphilic polymer comprises the copolymer poly(N-vinylpyrrolidone)-b-PLA; (b) the amphiphilic polymer is a poly(butadiene)-poly(ethylene oxide) (PB-PEO) diblock copolymer, or the amphiphilic polymer is a poly(dimethylsiloxane)-poly(ethylene oxide) (PDMS-PEO) diblock copolymer, or a poly(dimethylsiloxane)-poly(acrylic acid) (PDMS-PAA), the PB-PEO diblock copolymer preferably comprising 5-50 blocks PB and 5-50 blocks PEO, or the PB-PDMS diblock copolymer preferably comprising 5-100 blocks PDMS and 5-100 blocks PEO; (c) the amphiphilic polymer is a poly(lactide)-poly(ethylene oxide) / 1-palmitoyl-2-oleoyl-sn-glycero-3-phospho-L-serine (PLA-PEO / POPC) copolymer, preferably having a ratio of PLA-PEO to POPC (e.g., PLA-PEO / POPC) of 75 to 25 (e.g., 75 / 25); (d) the amphiphilic polymer is a poly(caprolactone)-poly(ethylene oxide) / 1-palmitoyl-2-oleoyl-sn-glycero-3-phospho-L-serine (PCL-PEO / POPC) copolymer, preferably having a ratio of PCL-PEO to POPC (e.g., PCL-PEO / POPC) of 75 to 25 (e.g., 75 / 25); (e) the amphiphilic polymer is polybutadiene-polyethylene oxide (BD), and / or (f) the first and / or second population of polymersomes are polymerized with a diblock copolymer PBD 21 -PEO 14 (BD21) and / or triblock copolymer PMOXA 12 -PDMS 55 -PMOXA 12 Including, Any of the methods of the present invention. [The present invention 1015] Any of the aforementioned methods of the invention, wherein the first population and / or the second population of polymersomes comprises a lipid polymer. [The present invention 1016] Any of the aforementioned methods of the invention, wherein the adjuvant associated with the second population of polymersomes is selected from the group consisting of CpG oligodeoxynucleotides (i.e., CpG ODN), components from bacterial and mycobacterial cell walls, and proteins. [The present invention 1017] A method for producing an encapsulated antigen or adjuvant in a polymersome, comprising the steps of: (i) dissolving an amphiphilic polymer in chloroform, preferably the amphiphilic polymer is polybutadiene-polyethylene oxide (BD); (ii) drying the dissolved amphiphilic polymer to form a polymer film; (iii) adding a solubilized antigen or a soluble adjuvant to the dried amphiphilic polymer film of step (ii), the adjuvant being preferably selected from the group consisting of CpG oligodeoxynucleotides (i.e. CpG ODN), components from bacterial and mycobacterial cell walls and proteins, the antigen being selected from the group consisting of: (a) a polypeptide, preferably the polypeptide antigen is according to any of the above inventions, more preferably the polypeptide antigen comprises a soluble portion of influenza hemagglutinin, swine influenza hemagglutinin, a spike protein, such as porcine epidemic diarrhea virus spike protein, a spike protein of a human pathogenic coronavirus, such as MERS-CoV spike protein or SARS-CoV-2 spike protein, ovalbumin (OVA), B16 peptide or MC38 peptide, most preferably the polypeptide antigen is selected from the group consisting of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:7, SEQ ID NO:8, SEQ ID NO:9, SEQ ID NO:10, SEQ ID NO:11, SEQ ID NO:12-14, SEQ ID NO:43-46, SEQ ID NO:34-41, SEQ ID NO:48-51 and SEQ ID NO: a polypeptide that is at least 60% or more (e.g., at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100%) identical to a polypeptide sequence selected from the group consisting of NO:65; (b) carbohydrates, (c) a polynucleotide which is not an antisense oligonucleotide and is preferably a DNA molecule or an mRNA molecule; (d) a combination of (a) and / or (b) and / or (c) A process selected from the group consisting of: (iv) rehydrating the polymer film of step (iii) to form polymer vesicles; (v) optionally filtering the polymer vesicles of step (iv) to purify the polymer vesicles into monodisperse vesicles; and / or (vi) optionally isolating the polymer vesicles of step (iv) or step (v) from unencapsulated antigen. [The present invention 1018] A polymersome produced by the method for producing an encapsulated antigen or adjuvant in a polymersome as defined in the present invention. [The present invention 1019] A composition comprising a first and a second population of polymersomes as defined in any one of claims 1001 to 1016. [The present invention 1020] A vaccine comprising a first and a second population of polymersomes as defined in any of claims 1001 to 1016 of the present invention or a composition as defined in claim 1019 of the present invention, further comprising a pharma- ceutically acceptable excipient or carrier. [The present invention 1021] A kit comprising a first and a second population of polymersomes as defined in any of claims 1001 to 1016 of the present invention or a composition as defined in claim 1019 of the present invention. [The present invention 1022] A method for treating or preventing an infectious disease, cancer or an autoimmune disease in a subject (e.g. a human) in need thereof, comprising administering to the subject a therapeutically effective amount of the first and second population of polymersomes as defined in claims 1001-1016 of the present invention or the composition as defined in claim 1019 of the present invention, preferably wherein the infectious disease is a viral infectious disease or a bacterial infectious disease. [The present invention 1023] A first and second population of polymersomes as defined in any of claims 1001 to 1016 or a composition as defined in claim 1019 for use as a medicament. The present application therefore meets the above-mentioned need by providing two distinct polymersome populations that improve the immunogenic properties of an antigen when administered, methods for producing such two polymersome populations, and compositions comprising such two polymersome populations, as described herein below, characterized in the claims, and illustrated by the accompanying examples and figures.

[0020] Sequence Listing Overview As used herein, references are made to UniProtKB accession numbers (unless otherwise indicated or otherwise specific, as available at http: / / www.uniprot.org / , e.g., UniProtKB Release 2017_12).

[0021] SEQ ID NO:1 is the amino acid sequence of the tumor neo-antigen polypeptide Reps1 P45A from the MC-38 mouse model of colon cancer.

[0022] SEQ ID NO:2 is the amino acid sequence of the tumor neo-antigenic peptide Adpgk R304M derived from the MC-38 mouse model of colon cancer.

[0023] SEQ ID NO:3 is the amino acid sequence of the tumor neo-antigen peptide Dpagt1 V213L derived from the MC-38 mouse model of colon cancer.

[0024] SEQ ID NO:4 is the amino acid sequence of chicken ovalbumin (OVA), UniProtKB Accession No. P01012.

[0025] SEQ ID NO:5 is the amino acid sequence of Influenza A virus (A / New York / 38 / 2016 (H1N1)) hemagglutinin, UniProtKB accession number A0A192ZYK0.

[0026] SEQ ID NO:6 is the amino acid sequence of Influenza A virus (A / Swine / 4 / Mexico / 2009 (H1N1)) hemagglutinin, UniProtKB Accession No. D2CE65.

[0027] SEQ ID NO:7 is the amino acid sequence of Influenza A virus (A / Puerto Rico / 8 / 1934 (H1N1)) hemagglutinin.

[0028] SEQ ID NO:8 is the amino acid sequence of Influenza A virus (A / California / 07 / 2009 (H1N1)) hemagglutinin.

[0029] SEQ ID NO:9 is the amino acid sequence of the tumor neo-antigen polypeptide CD8 Trp2 173-196 from the melanoma B16-F10 mouse model.

[0030] SEQ ID NO:10 is the amino acid sequence of the tumor neo-antigen polypeptide CD4 M30 Kif18b K739N from the melanoma B16-F10 mouse model.

[0031] SEQ ID NO:11 is the amino acid sequence of the tumor neo-antigen polypeptide CD4 M44 Cpsf3l D314N from the melanoma B16-F10 mouse model.

[0032] SEQ ID NO:12 is the amino acid sequence of the soluble portion (amino acid residues 19 to 1327) of the porcine epidemic diarrhea virus (PEDv) spike protein (S protein) (UniProtKB Accession No. V5TA78).

[0033] SEQ ID NO:13 is the amino acid sequence of the S1 region (amino acid residues 19 to 739) of the PEDv spike protein (S protein).

[0034] SEQ ID NO:14 is the amino acid sequence of the S2 region (amino acid residues 739 to 1327) of the PEDv spike protein (S protein).

[0035] SEQ ID NO:15 is the amino sequence of enhanced green fluorescent protein (eGFP).

[0036] SEQ ID NO:16 is the sequence of a CD8 T cell peptide epitope (SIINFEKL).

[0037] SEQ ID NO:17 is the sequence of a CD8 T cell peptide epitope (SVYDFFVWL).

[0038] SEQ ID NO:18 is a class B CpG oligodeoxynucleotide CpG ODN1826 (5'-tccatgacgttcctgacgtt-3') available from InvivoGen.

[0039] SEQ ID NO:19 is the amino acid sequence of the SARS-CoV-2 spike protein according to UniProtKB accession number P0DTC2.

[0040] SEQ ID NO:20 is the amino acid sequence of the SARS-CoV-2 spike protein according to GenBank accession number QII57278.1.

[0041] SEQ ID NO:21 is the amino acid sequence of the SARS-CoV-2 spike protein according to GenBank accession number YP_009724390.1.

[0042] SEQ ID NO:22 is the amino acid sequence of the SARS-CoV-2 spike protein according to GenBank accession number QIO04367.1.

[0043] SEQ ID NO:23 is the amino acid sequence of the SARS-CoV-2 spike protein according to GenBank accession number QHU79173.2.

[0044] SEQ ID NO:24 is the amino acid sequence of the SARS-CoV-2 spike protein according to GenBank accession number QII87830.1.

[0045] SEQ ID NO:25 is the amino acid sequence of the SARS-CoV-2 spike protein according to GenBank accession number QIA98583.1.

[0046] SEQ ID NO:26 is the amino acid sequence of the SARS-CoV-2 spike protein according to GenBank accession number QIA20044.1.

[0047] SEQ ID NO:27 is the amino acid sequence of the SARS-CoV-2 spike protein according to GenBank accession number QIK50427.1.

[0048] SEQ ID NO:28 is the amino acid sequence of the SARS-CoV-2 spike protein according to GenBank accession number QHR84449.1.

[0049] SEQ ID NO:29 is the amino acid sequence of the SARS-CoV-2 spike protein according to GenBank accession number QIQ08810.1.

[0050] SEQ ID NO:30 is the amino acid sequence of the SARS-CoV-2 spike protein according to GenBank accession number QIJ96493.1.

[0051] SEQ ID NO:31 is the amino acid sequence of the SARS-CoV-2 spike protein according to GenBank accession number QIC53204.1.

[0052] SEQ ID NO:32 is the amino acid sequence of the SARS-CoV-2 spike protein according to GenBank accession number QHZ00379.1.

[0053] SEQ ID NO:33 is the amino acid sequence of the SARS-CoV-2 spike protein according to GenBank accession number QHS34546.1.

[0054] SEQ ID NO:34 is the amino acid sequence of a soluble fragment of the SARS-CoV-2 spike protein corresponding to positions 16 to 1213 of UniProtKB accession number P0DTC2.

[0055] SEQ ID NO:35 is the amino acid sequence of a soluble fragment of the SARS-CoV-2 spike protein corresponding to positions 14 to 1204 of UniProtKB accession number P0DTC2.

[0056] SEQ ID NO:36 is the amino acid sequence of a soluble fragment of the SARS-CoV-2 spike protein.

[0057] SEQ ID NO:37 is the amino acid sequence of a soluble fragment of the SARS-CoV-2 spike protein corresponding to positions 16 to 685 of UniProtKB accession number P0DTC2.

[0058] SEQ ID NO:38 is the amino acid sequence of a soluble fragment of the SARS-CoV-2 spike protein corresponding to positions 686 to 1213 of UniProtKB accession number P0DTC2.

[0059] SEQ ID NO:39 is the amino acid sequence of a soluble fragment of the SARS-CoV-2 spike protein corresponding to positions 646 to 1204 of UniProtKB accession number P0DTC2.

[0060] SEQ ID NO:40 is the amino acid sequence of a soluble fragment of the SARS-CoV-2 spike protein.

[0061] SEQ ID NO:41 is the amino acid sequence of a soluble fragment of the SARS-CoV-2 spike protein corresponding to positions 318 to 524 of UniProtKB accession number P0DTC2.

[0062] SEQ ID NO:42 is the amino acid sequence of the MERS-CoV spike protein according to UniProtKB accession number K0BRG7.

[0063] SEQ ID NO:43 is the amino acid sequence of a soluble fragment of the MERS-CoV spike protein corresponding to positions 1 to 1297 of UniProtKB accession number K0BRG7.

[0064] SEQ ID NO:44 is the amino acid sequence of a soluble fragment of the MERS-CoV spike protein corresponding to positions 18 to 725 of UniProtKB accession number K0BRG7.

[0065] SEQ ID NO:45 is the amino acid sequence of a soluble fragment of the MERS-CoV spike protein corresponding to positions 726 to 1296 of UniProtKB accession number K0BRG7.

[0066] SEQ ID NO:46 is the amino acid sequence of a soluble fragment of the MERS-CoV spike protein corresponding to positions 377 to 588 of UniProtKB accession number K0BRG7.

[0067] SEQ ID NO:47 is the amino acid sequence of the SARS-CoV-1 spike protein according to UniProtKB accession number P59594.

[0068] SEQ ID NO:48 is the amino acid sequence of a soluble fragment of the SARS-CoV-1 spike protein corresponding to positions 14 to 1195 of UniProtKB accession number P59594.

[0069] SEQ ID NO:49 is the amino acid sequence of a soluble fragment of the SARS-CoV-1 spike protein corresponding to positions 14 to 667 of UniProtKB accession number P59594.

[0070] SEQ ID NO:50 is the amino acid sequence of a soluble fragment of the SARS-CoV-1 spike protein corresponding to positions 668 to 1195 of UniProtKB accession number P59594.

[0071] SEQ ID NO:51 is the amino acid sequence of a soluble fragment of the SARS-CoV-1 spike protein corresponding to positions 306 to 527 of UniProtKB accession number P59594.

[0072] SEQ ID NO:52 is the amino acid sequence of the furin cleavage site of the SARS-CoV-2 spike protein.

[0073] SEQ ID NO:53 is the amino acid sequence of the mutant furin cleavage site of the SARS-CoV-2 spike protein.

[0074] SEQ ID NO:54 is the amino acid sequence of the foldon domain.

[0075] SEQ ID NO:55 is the amino acid sequence of the GCN4 domain.

[0076] SEQ ID NO:56 is the amino acid sequence of the immunosilenced GCN4 domain.

[0077] SEQ ID NO:57 is the amino acid sequence of the honeybee melittin leader sequence.

[0078] SEQ ID NO:58 is the amino acid sequence of the furin cleavage site of the MERS-CoV spike protein.

[0079] SEQ ID NO:59 is the amino acid sequence of a mutant furin cleavage site of the MERS-CoV spike protein.

[0080] SEQ ID NO:60 is the amino acid sequence of the furin cleavage site of the SARS-CoV-1 spike protein.

[0081] SEQ ID NO:61 is the amino acid sequence of the mutant furin cleavage site of the SARS-CoV-1 spike protein.

[0082] SEQ ID NO:62 is the nucleotide sequence of the CpG oligonucleotide ODN2006.

[0083] SEQ ID NO:63 is the nucleotide sequence of the CpG oligonucleotide ODN2007.

[0084] SEQ ID NO:64 is the nucleotide sequence of the CpG oligonucleotide ODN2216.

[0085] SEQ ID NO:65 is the amino acid sequence of a soluble fragment of the SARS-CoV-2 spike protein, corresponding to positions 19 to 1204 of UniProtKB accession number P0DTC2, but containing a mutant furin cleavage site.

[0086] SEQ ID NO:66 is the amino acid sequence of the SARS-CoV-2 spike protein, corresponding to positions 19 to 1273 of UniProtKB accession number P0DTC2, but containing a mutant furin cleavage site. [Brief description of the drawings]

[0087] [Figure 1] FIG. 1 is a schematic diagram of immunization with polymersomes of the invention encapsulating antigen and measuring humoral and cellular responses. [Figure 2A] The results of dynamic light scattering results for polymersomes of the present invention are shown. Figure 2A is a dynamic light scattering plot of OVA-encapsulated polymersomes, which are a monodisperse population of 173.1 nm (diameter). Figure 2B is a table of the average diameter (Z-average) measured by DLS for various polymersomes encapsulating various antigens. The names of the formulations shown in brackets, such as "ACM-OVA", "ACM-CpG", "ACM-OVA-CpG" and "ACM-Trp2", are used in other sections of this application. [Figure 2B] See legend to Figure 2A. [Diagram 3] FIG. 1 shows the elution profile of OVA-encapsulated polymersomes in size-exclusion chromatography. [Figure 4] FIG. 1 shows sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of OVA-encapsulated polymersomes. [Figure 5A] The results of encapsulation of nucleic acid (here, the gene encoding enhanced green fluorescent protein (eGFP)) into polymersomes of the present invention and uptake of the nucleic acid-encapsulated polymer into cells are shown. FIG. 5A shows the fluorescence intensity uptake of various polymersomes into the cell interior and eGFP expression based on DNA encapsulated in the polymersomes. FIG. 5B shows the fluorescence image of a cell transfected with DNA-encapsulated polymersomes. FIG. 5C shows the fluorescence image of a cell transfected with DNA-encapsulated polymersomes. [Figure 5B] See legend to Figure 5A. [Figure 5C] See legend to Figure 5A. [Figure 6] Antibody titers from mouse sera immunized with PBS, OVA alone, OVA with SAS adjuvant, and OVA-encapsulated polymersomes without adjuvant are shown. Only ACM encapsulating OVA (hereinafter, "ACM" refers to the polymersomes of the present invention) was able to induce IgG titers. [Figure 7] Figure 1 shows antibody titers from mouse sera immunized with PBS, HA only, and HA-encapsulated polymersomes without adjuvant. HA-encapsulated ACM (polymersomes of the invention) was able to induce IgG titers. [Figure 8]Results are shown for the MC-38 mouse tumor model. Tumor volume was monitored in mice immunized with free peptide (open circles), peptide encapsulated in ACM (closed squares, polymersomes of the invention) or peptide encapsulated in ACM with anti-PD1 antibody treatment (closed triangles). Tumor growth was modified by peptide encapsulated in ACM (polymersomes of the invention) compared to free peptide, and it was further enhanced by the addition of anti-PD1 antibody. No adjuvant was added to any group. [Figure 9] IgG antibody titers and virus neutralization responses (against PEDv USA / Colorado / 2013 (CO / 13) strain) from mouse sera immunized with PBS and a soluble fragment of PEDv S protein encapsulated in polymersomes used as described herein ("spike protein encapsulated polymersomes"), as well as, for comparison, from mouse sera immunized with killed PED virus ("killed PEDv") and ACM polymersomes only (i.e., no antigen, "polymersomes only"). From the IgG titers in FIG. 9, it is clear that both the ACM encapsulated PEDv S protein fragment and the killed virus induce IgG titers. The virus neutralization data shows that only the ACM encapsulated PEDv S protein resulted in significant neutralization titers, while the negative control (ACM polymersomes without any antigen) and the killed PED virus showed negligible neutralization responses. [Figure 10]Virus neutralization data (against the PEDv USA / Colorado / 2013 (CO / 13) strain) from sera generated from mice following immunization with PBS and various polymersomes (e.g., BD21 (described below), PDMS46-PEO37 (simply referred to as "PDMS" in the figures), PDMS46-PEO37 with DSPE-PEG (distearoylphosphatidylethanolamine [DSPE] polyethylene glycol) as added lipid, and polyethylene glycol-polylactic acid (PLA-PEG) with added asolectin lipid (a commercially available phospholipid derived from soybean) encapsulating either the full-length soluble PED spike protein ("BD21 with soluble S protein") or its S1 or S2 fragments (all other cases)) are shown. It is evident from FIG. 10 that the group of mice immunized with PBS samples does not show any virus neutralization response, whereas the polymersome formulations, irrespective of whether they encapsulate the full-length protein or its fragment, all show varying degrees of virus neutralization response. [Figure 11] 11 shows IgA antibody titers from pigs orally immunized with PEDv S protein encapsulated in ACM without adjuvant. Titers are from fecal swabs. As can be seen in FIG. 11, the titers increase over time. This indicates that the polymersomes of the present invention encapsulating PEDv S protein and administered orally can induce an immune response in pigs. [Figure 12] Schematic representation of the Porcine Epidemic Diarrhea Virus (PEDv) spike protein (S protein) (UniProtKB Accession No. V5TA78) and soluble fragments of SEQ ID NO:12 (amino acid residues 19-1327), SEQ ID NO:13 (amino acid residues 19-739) and SEQ ID NO:14 (amino acid residues 739-1327) used for encapsulation of soluble S protein in polymersomes and subsequent immunization / vaccination of mice and pigs as described herein. [Figure 13]Figure 13 shows tumor growth curves after prophylactic vaccination with ACM OVA formulations. Tumor growth curves for mice inoculated with 105 B16-OVA cells after administration of different OVA formulations. Figure 13A shows PBS group, free OVA and CpG administration group, and ACM-encapsulated OVA and free CpG co-administration group, and Figure 13B shows PBS group, co-administered ACM-encapsulated OVA and ACM-encapsulated CpG, and OVA and CpG encapsulated ACM together. [Figure 14A] Tumor growth curves after therapeutic vaccination with ACM OVA formulations. Tumor growth curves for mice vaccinated with different ACM OVA formulations followed by inoculation with 105 B16-OVA cells. Figure 14A) PBS group, free OVA and CpG group, and co-administration group with OVA and free CpG encapsulated in ACM, B) PBS group, free OVA and CpG encapsulated ACM, and OVA and CpG encapsulated ACM encapsulated in co-administered ACM, C) OVA-specific CD8 T cells quantified using dextramer specific for CD8 T cell SIINFEKL (SEQ ID NO: 16) peptide epitope. [Figure 14B] See legend to Figure 14A. [Figure 14C] See legend to Figure 14A. [Figure 15A] Tumor growth curves of therapeutic vaccination of ACM melanoma B16F10 formulation in mice inoculated with 105 B16F10 cells. Figure 15A shows PBS group, co-administered free Trp2 (SEQ ID NO:9) and CpG, co-administered ACM and CpG with Trp2, co-administered free Trp2 and CpG in ACM, and Trp2 and CpG in ACM co-administered together, Figure 15B shows Trp2-specific CD8-specific T cells quantified in blood using pentamer specific for CD8 T cell SVYDFFVWL (SEQ ID NO:17) peptide epitope, and Figure 15C shows CD8 T cell infiltration in tumors. [Figure 15B] See legend to Figure 15A. [Figure 15C] See legend to Figure 15A. [Figure 16] 1 shows dynamic light scattering (DLS) spectra of OVA-conjugated ACM. [Figure 17] Characterization of OVA-conjugated ACM: FIG. 17A shows the size-exclusion chromatography (SEC) profile of OVA-conjugated ACM, and FIG. 17B shows the SDS-PAGE of samples loaded from the SEC peak and stained using silver staining. [Figure 18] 1 shows the DLS spectrum of HA-conjugated ACM. [Figure 19] Immunoblots of ACM-conjugated HA samples show different mobility of coupled and free HA. [Figure 20] SEC profile of HA-conjugated ACM (mAU, light grey trace) overlaid with ELISA signal (OD450, black trace) performed on all collected fractions. [Figure 21] Antibody titers from sera of C57Bl / 6 mice immunized with PBS, free OVA, free OVA and SAS, BD21-encapsulated OVA and BD21-conjugated OVA are shown (p<0.01). [Figure 22] Antibody titers from serum of Balb / c mice immunized with PBS, free HA, BD21-encapsulated HA and BD21-conjugated HA are shown. [Figure 23A]FIG. 23A is a schematic representation of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein (S protein) (UniProtKB accession number: P0DTC2) and soluble fragments of SEQ ID NO:34 (amino acid residues 16-1213), SEQ ID NO:37 (amino acid residues 16-685) and SEQ ID NO:38 (amino acid residues 685-1213). According to UniProtKB, amino acids 1214-1234 form the transmembrane region and 1235-1273 form the intraviral region. The end points of the S1 and S2 segments, the transmembrane region, and / or the intraviral region may vary depending on the prediction software. FIG. 23B represents a protocol for immunization of mice with ACM encapsulating the SARS-CoV-2 spike protein. Figure 23C represents IgG titers measured in Balb / c mice on day 35 immunized with the following formulations: BD21 encapsulated soluble S1 and S2 segments co-administered with adjuvant (group 1), BD21 encapsulated soluble S1 and S2 segments (group 2), BD21 encapsulated soluble S2 segment co-administered with encapsulated adjuvant (group 3), and PBS as a negative control (group 4). [Figure 23B] See legend to Figure 23A. [Figure 23C] See legend to Figure 23A. [Figure 24] The protocol and results of mice immunized with full-length soluble encapsulated SARS-CoV-2 spike protein encapsulated in ACM are shown. Figure 24A shows the immunization protocol. Figure 24B shows the IgG antibody titers against SARS-CoV-2 spike protein 28 days after the first immunization for the four groups. The following formulations were prepared: (i) free recombinant spike protein "fSpike", (ii) BD21 polymersome encapsulated spike protein ("ACM-Spike"), (iii) a mixture of free spike protein and free CpG adjuvant ("fSpike fCpG"), (iv) a mixture of BD21 polymersome encapsulated spike protein and BD21 polymersome encapsulated CpG ("ACM-Spike ACM-CpG"). [Diagram 25] 1 shows the results of a virus neutralization assay (PEDv) following immunization of guinea pigs with ACM encapsulating PEDv S2 spike protein mixed with ACM encapsulating CpG administered by different routes. [Figure 26] The protocol and results of mice immunized with ACM encapsulating MERS spike protein are shown. Figure 26A shows the immunization protocol, and Figure 26B shows the results of ELISA for the MERS-CoV spike protein S1 domain. Figure 26C shows the results of a virus neutralization assay (MERS-CoV). [Figure 27] 1 shows the results of a virus neutralization assay for mice immunized with ACM encapsulating either the S1 or S2 domain of the PEDv spike protein, or a mixture of the S1 and S2 domains (PEDv). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0088] Detailed Description of the Invention In the following detailed description, reference is made to the accompanying examples and drawings, which show, by way of illustration, specific details and embodiments that may be taken in carrying out the present invention. These embodiments are described in sufficient detail to enable one skilled in the art to practice the invention. Other embodiments may be utilized, such that structural, logical and optional changes may be made without departing from the scope of the present invention. The various aspects of the present invention described herein are not necessarily mutually exclusive, as aspects of the present invention may be combined with one or more other aspects to form new embodiments of the present invention.

[0089] The present invention is based on the surprising discovery that two separate populations of polymersomes, where a first population of polymersomes is associated only with an antigen and a second population of polymersomes is associated only with an adjuvant, when administered together, improve the immune response to an antigen, thereby providing an immunological or therapeutic effect against, for example, an infectious disease or cancer. (See, for example, Examples 7-9 or Example 19 herein, where Example 8 shows that administration of a first polymersome population encapsulating an antigen together with a separate second polymersome population encapsulating CpG (an adjuvant) results in an immune response in mice that correlates with both tumor burden and T cell infiltration; Example 9 shows that administration of the immunogenic tumor neo-antigen Trp2 peptide encapsulated in a first population of polymersomes together with CpG oligonucleotides (an adjuvant) encapsulated in a second (separate) population results in a much stronger anti-tumor response compared to, for example, free Trp2 peptide; and Example 19 shows that the immune response against the spike protein of the Sars-CoV-2 virus is highest when the spike protein of Sars-CoV-2 is encapsulated in a first population of polymersomes and the CpG oligonucleotides (an adjuvant) are encapsulated in a second (separate) population. The discovery that two distinct polymersome populations result in an improved immune response has the additional advantage of allowing the two polymersome populations to be produced separately / independently from each other. This in turn simplifies, for example, the GMP production of each vaccine or therapeutic composition, since a first population of polymersomes, e.g., comprising an antigen encapsulated in the polymersomes or conjugated to the surface of the polymersomes, can be produced under standardized GMP conditions, while a second population of polymersomes, e.g., comprising an adjuvant encapsulated in the polymersomes or conjugated to the surface of the polymersomes, can also be produced under standardized conditions. These two populations can then be combined in the manufacturing process (to obtain a composition that combines both polymersome populations for co-administration) or administered separately to a subject.Such a drug / vaccine manufacturing process is much easier to manage than, for example, encapsulating both an antigen and an adjuvant in the same polymersome population.

[0090] The antigen can be associated with the first population of polymersomes by any possible interaction between the antigen and the first population of polymersomes. For example, the antigen can be encapsulated within the first population of polymersomes, as described in co-pending PCT application PCT / EP2019 / 051853, filed January 25, 2019, the entire contents of which are incorporated herein by reference. Alternatively, the antigen can be incorporated into the surrounding membrane of the polymersomes of the first population of polymersomes, as described in international application WO2014 / 077781. The antigen can also be conjugated via a covalent bond to the outer surface of the polymersomes of the first population of polymersomes, as described in co-pending European patent application No. 18193946.3, filed September 12, 2018, the entire contents of which are incorporated herein by reference.

[0091] Furthermore, the antigen can be conjugated to the outer surface of the polymersomes of the first polymersome population via non-covalent bonds. Examples of such non-covalent bonds include electrostatic interactions, such as salt bridges between positively and negatively charged residues present on the surface of the polymersome or on the surface of the antigen. For example, a salt bridge can be formed between a positively charged amino group (NH2 group) and a negatively charged carboxylic acid group (COOH). Yet another example of such a non-covalent interaction between the first polymersome population and the antigen is a binding pair between streptavidin and biotin, avidin and biotin, streptavidin and a streptavidin binding peptide, or avidin and an avidin binding peptide. For example, polymersomes with biotin groups located on the polymersome surface can be prepared as described in Broz et al. "Cell targeting by a generic receptor-targeted polymer nanocontainer platform" Journal of Controlled Release. 2005;102(2):475-488, and can be reacted with antigen conjugated to streptavidin or avidin. Non-covalent biotin-streptavidin conjugates of polymersomes and antigens can also be prepared as described in Egli et al. "Functionalization of Block Copolymer Vesicle Surfaces Polymers" 2011,3(1),252-280. In this context, the term "antigen associated with the first population of polymersomes" as used herein does not mean that only one specific antigen is associated with the first population of polymersomes, but also encompasses that more than one, e.g., two or more antigens, can be associated with the first population of polymersomes. As a specific example, for example, two or more immunogenic peptides can be associated with the first population of polymersomes of the invention. It is also possible to associate one or more immunogenic peptides and the respective nucleic acid molecules encoding those peptides with the first population of polymersomes as used herein.The term "antigen associated with a first population of polymersomes" as used herein also means that two or more first polymersome populations can be used, each carrying a different antigen. For example, it is possible to use two different antigenic peptides, each of which is associated with a separate first polymersome population of the invention.

[0092] The adjuvant can be associated with the second population of polymersomes in the same way that the antigen can be associated with the first population of polymersomes, by any possible interaction. That is, the adjuvant can be encapsulated within the first population of polymersomes, as described in co-pending PCT application PCT / EP2019 / 051853, filed January 25, 2019, the entire contents of which are incorporated herein by reference. Alternatively, the adjuvant can be incorporated into the surrounding membrane of the polymersomes of the first population of polymersomes, as described in international application WO2014 / 077781. Specific examples of adjuvants that are / can be incorporated into the surrounding membrane of polymersomes (of the second polymersome population) include synthetic monophosphoryl lipid A (see Cluff, "Monophosphoryl Lipid A (MPL) as an Adjuvant for Anti-Cancer Vaccines: Clinical Results," in Lipid A in Cancer Therapy, edited by Jean-Francois Jeannin, Landes Bioscience and Springer, 2009), polysorbate 80, alpha-DL-tocopherol, dioleoyl-3-trimethylammonium propane (DOTAP), the cationic lipid 1-[2-(oleoyloxy)ethyl]-2-oleyl-3-(2-hydroxyethyl)imidazolinium chloride (DOTIM) (Bernstein et al., "The Adjuvant CLDC Increases Protection of a Herpes Simplex Type 2 Glycoprotein D Vaccine in Guinea Pig," Vaccine. May 2010). 7;28(21):3748-3753, or the synthetic amphiphile dimethyldioctadecylammonium (DDA) (see Smith Korsholm et al "The adjuvant mechanism of cationic dimethyldioctadecylammonium liposomes" Immunology, 121, 216-226), to name just a few examples.In this regard, it is clear that one or more adjuvants can be present in the polysomes of the second polymersome population referred to herein. For example, the second polymersome population can include an encapsulated adjuvant, such as a CpG oligonucleotide, and an adjuvant incorporated into the surrounding membrane of the polymersome, such as monophosphoryl lipid A or DOTAP (but in accordance with the disclosure above, the second polymersome population does not include an antigen, i.e., the second polymersome population does not contain any antigen).

[0093] In line with the above, it is of course possible to conjugate the adjuvant via a covalent bond to the outer surface of the polymersomes of the first polymersome population, as described in co-pending European Patent Application No. 18193946.3, filed September 12, 2018, the entire contents of which are incorporated herein by reference. Alternatively, the conjugation of the adjuvant to the outer surface of the polymersomes may be performed via a non-covalent bond, such as a biotin-streptavidin interaction. It is noted here that CpG oligonucleotides, such as the class B CpG oligodeoxynucleotide CpG ODN1826 (5'-tccatgacgttcctgacgtt-3', SEQ ID NO:18), are available in biotinylated form and can therefore be easily reacted with biotinylated polymersomes that have been "modified" with streptavidin, as described in Broz et al., Journal of Controlled Release. 2005, supra. It is also clear from this example that the second polymersome population can carry more than one adjuvant, for example a CpG oligonucleotide covalently or non-covalently conjugated to the outer surface of the polymersome and a further adjuvant such as monophosphoryl lipid A or DOTAP incorporated into the surrounding membrane of the polymersome. It is further clear that the same adjuvant can be associated with the second polymersome population in a different way, for example a CpG oligonucleotide can be covalently or non-covalently conjugated to the outer surface of the polymersome at the same time as being encapsulated in the polymersome. This allows a larger amount of adjuvant to be administered, if desired.

[0094] In line with the above disclosure, any kind of first polymersome population can be used for administration with any kind of second polymersome population, regardless of how the antigen and adjuvant are associated with the first and second polymersome populations. For example, the first population of polymersomes can have an antigen encapsulated within the polymersomes, and the second population of polymersomes can also have an adjuvant encapsulated within the polymersomes. Alternatively, the first population of polymersomes can have an antigen covalently or non-covalently conjugated to the outer surface of the polymersomes, while the second population of polymersomes can have an adjuvant covalently or non-covalently conjugated to the outer surface of the polymersomes. As yet another purely illustrative example, the first population of polymersomes can have an antigen incorporated in the surrounding membrane of the polymersomes, and the second population of polymersomes can also have an adjuvant incorporated in the surrounding membrane of the polymer. As a further embodiment, a first population of polymersomes can have an antigen encapsulated within the polymersomes, while a second population of polymersomes can have (a) an adjuvant covalently or non-covalently conjugated to the outer surface of the polymersomes, or (b) an adjuvant incorporated into the surrounding membrane of the polymersomes. As yet another embodiment, a first population of polymersomes can have an antigen covalently conjugated to the outer surface of the polymersomes, while a second population of polymersomes can have an adjuvant encapsulated within the polymersomes.

[0095] Now, to elaborate on the administration of the two polymersome populations of the present invention, the first population of polymersomes and the second population of polymersomes can be administered simultaneously (i.e. at the same time) or at different times. When the two populations are administered simultaneously, the two polymersome populations can be administered together (i.e. by co-administration). In that case, the two polymersome populations are mixed or mixed together prior to administration, so that they are present in the same composition, for example in a pharma- ceutically acceptable carrier (e.g. physiological buffer or a solid formulation suitable for oral administration). However, when administered at the same time, it is also possible to administer each of the two polymersome populations separately. In that case, the two polymersome populations can of course not be mixed with each other prior to administration, for example by two or more separate injections.

[0096] The two polymersome populations are known to induce an immune response in a subject and can be administered to a selected subject in any manner suitable for administering the polymersome population to a given subject. When fish or agricultural animals such as chickens, pigs or sheep are immunized, it may be advantageous to use oral administration, for example, and to formulate a composition containing the two polymersome populations of the present invention as a food additive. Alternatively, intradermal administration utilizing a syringe gun or jet injector may be used for agricultural animals. Invasive and non-invasive administration can be used for humans. Suitable routes of administration for both humans and non-human animals include, but are not limited to, oral administration, intranasal administration, administration to mucosal surfaces, inhalation, administration, intraperitoneal administration, subcutaneous administration, intravenous administration or intramuscular administration.

[0097] To elaborate on the conjugation of antigens and / or adjuvants to the outer surface of polymersomes of either the first or second polymersome population, the covalent bond can be any suitable covalent bond that can conjugate antigens (e.g., antigens of the present invention) or adjuvants to the outer surface of polymersomes of the present invention. Conjugation reactions that produce the covalent bonds of the present invention are well known in the art (e.g., NHS-EDC conjugation, reductive amination conjugation, sulfhydryl conjugation, "click" and "photoclick" conjugation, pyrazoline conjugation, etc.). Non-limiting examples of such covalent bonds and methods of their generation are listed herein below. Thus, in some aspects, the covalent linkage for conjugating the antigen or adjuvant of the invention to the outer surface of the polymersome of the invention comprises (i) an amide moiety (e.g., as described in the Examples section herein), and / or (ii) a secondary amine moiety (e.g., as described in the Examples section herein), and / or (iii) a 1,2,3-triazole moiety (e.g., as described in van Dongen et al., 2008, Macromol. Rapid Communications, 2008, 29, 321-325), preferably the 1,2,3-triazole moiety is a 1,4-disubstituted [1,2,3] triazole moiety or a 1,5-disubstituted [1,2,3] triazole moiety (e.g., as described in Boren et al., 2008), and / or (iv) a pyrazoline moiety (e.g., as described in de Hoog et al., Polym. Chem., 2012, 3, 302-306), and / or an ether moiety. In this regard, it should be noted that the formation of conjugation / covalent bonds between the outer surface of the polymersome and the antigen may require modification of both the polymersome and the antigen, e.g., a protein. In addition to the classical chemical conjugation chemistries (reactions) described above, it is also possible to form covalent bonds between the outer surface of the polymersome and the antigen by enzymatic reactions.

[0098] In some aspects, the present invention relates to NHS-EDC conjugation (i.e., conjugation based on N-hydroxysuccinimide (NHS) and 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide (EDC)), which is one of the exemplary alternative methods of conjugating antigens to the polymersomes of the present invention. In this method, a carboxylic acid group reacts with EDC to generate an intermediate O-acylisourea, which then reacts with a primary amine to form an amide moiety with the carboxyl group.

[0099] In some aspects, the present invention relates to reductive amination conjugation, another exemplary alternative method of conjugating antigens or adjuvants to the polymersomes of the present invention, in which an aldehyde-containing compound is conjugated to an amine-containing compound to form a Schiff base intermediate, which then undergoes reduction to form a stable secondary amine moiety.

[0100] In some aspects, the present invention relates to sulfhydryl conjugation, another exemplary alternative method of conjugating antigens or adjuvants to the polymersomes of the present invention, in which sulfhydryl (-SH)-containing compounds (such as those present in the side chains of cysteine) are conjugated to sulfhydryl-reactive chemical groups (such as maleimides) by alkylation or disulfide exchange to form thioether or disulfide bonds, respectively.

[0101] In some aspects, the present invention relates to the so-called "click" reaction (also known as "azide-alkyne cycloaddition") on the polymersome surface, which is another exemplary alternative method for conjugating antigens to the polymersomes of the present invention (e.g., as described in van Dongen et al., 2008, supra). In this method, an aqueous solution of an azide-functionalized antigen (e.g., a polypeptide) is added to a dispersion of polymersomes, then a premixed aqueous solution of Cu(II)SO4·5H2O and sodium ascorbate and a bathophenanthroline ligand is added to the resulting dispersion of polymersomes and left for 60 hours at 4°C, then the dispersion is filtered with a 100 nm cutoff and spun to dryness to generate 1,2,3-triazole moieties. In this context, copper-catalyzed azide-alkyne cycloaddition (also known as CuAAC) allows the synthesis of specifically 1,4-disubstituted regioisomers, whereas ruthenium-catalyzed azide-alkyne cycloaddition (also known as RuAAC) (e.g. using Cp as catalyst) has been shown to be effective in the synthesis of 1,4-disubstituted regioisomers. * It should also be noted that the use of RuCl(PPh3)2 allows for the production of 1,5-disubstituted triazoles (see R. Johansson, Johan & Beke-Somfai, Tamas & Said Stalsmeden, Anna & Kann, Nina. (2016). Ruthenium-Catalyzed Azide Alkyne Cycloaddition Reaction: Scope, Mechanism, and Applications. Chemical Reviews. 116.10.1021 / acs.chemrev.6b00466).

[0102] In some aspects, the present invention relates to another exemplary alternative method of conjugating antigens to the polymersomes of the present invention, the photoinduced generation of a nitrile imine intermediate (e.g., generated from a bisaryl-tetrazole) and its cycloaddition to an alkene (so-called photoinduced cycloaddition or "photoclick" reaction, e.g., as described in de Hoog et al., supra, 2011). In this method, ABA block copolymers are methacrylate (MA)- or hydroxyl-terminated with tetrazole by photoinduced generation of a nitrile imine intermediate to produce ABA polymersomes containing MA-ABA copolymers and hydroxyl-terminated ABA copolymers, which are then reacted with a tetrazole-containing antigen (HRP) under UV irradiation to generate pyrazoline moieties.

[0103] The covalent bond conjugating the antigen or adjuvant to the outer surface of the polymersome can be formed between an atom / group of a molecule, such as an amphiphilic polymer, that is part of (present in) the surrounding membrane of the polymersome. Alternatively, the covalent bond between the antigen or antigen and the outer surface of the polymer is formed via a linker moiety attached to a molecule that is part of (present in) the surrounding membrane of the polymersome. The linker may have any suitable length and can have a length of one main chain atom (e.g., when the linker is a simple carbonyl group (C=O) that results in an amide or ester moiety that forms the covalent bond). A specific example of such a "one atom / linker moiety" having a length of one main atom is BD 21Modification of the amphiphilic polymer BD21 with Dess-Martin periodinane, as carried out in the Examples, to obtain -CHO (i.e. a terminal aldehyde group), which is then used to form an amine bond with a selected antigen (hemagglutinin is used in the Experimental Section as an example of a purely illustrative antigen). Alternatively, the linker moiety may have a length of several hundred or even more main chain atoms, for example a moiety such as polyethylene glycol (PEG), which is often used for the conjugation (covalent coupling) of polypeptides with molecules of interest. As a purely illustrative example, see the distearoylphosphatidylethanolamine [DSPE] polyethylene glycol (DSPE-PEG) conjugate described below and used in the Examples of this application. The DSPE-PEG(3000) linker moiety used in the Examples has about 65 ethylene oxide (CH2-CH2-O) subunits, thus about 325 main chain atoms in the PEG moiety alone, for a total length of about 408 main chain atoms. In line with the above exemplary embodiments, the linker moiety may comprise 1 to about 550 main chain atoms, 1 to about 500 main chain atoms, 1 to about 450 main chain atoms, 1 to about 350 main chain atoms, 1 to about 300 main chain atoms, 1 to about 250 main chain atoms, 1 to about 200 main chain atoms, 1 to about 150 main chain atoms, 1 to about 100 main chain atoms, 1 to about 50 main chain atoms, 1 to about 30 main chain atoms, 1 to about 20 main chain atoms, 1 to about 15 main chain atoms, or 1 to about 12 main chain atoms, or 1 to about 10 main chain atoms, where the main chain atoms are carbon atoms optionally replaced with one or more heteroatoms selected from the group consisting of N, O, P, and S.

[0104] According to the disclosure above, the linker moiety can be a peptide linker or a linear or branched hydrocarbon-based linker. The linker moiety may be a copolymer with different block lengths. The linker moiety used in the present invention can include a membrane anchoring domain that incorporates the linker moiety into the membrane of the polymersome. Such a membrane anchoring domain can include a lipid such as a phospholipid or a glycolipid. The glycolipid used in the membrane anchoring domain can include glycophosphatidylinositol (GPI), which is a widely used membrane anchoring domain (see, for example, International Patent Applications WO2009 / 127537 and WO2014 / 057128). The phospholipid used in the linker of the present invention can be a sphingophospholipid or a glycerophospholipid. In a specific example of such a linker, the sphingophospholipid can include distearoylphosphatidylethanolamine [DSPE] conjugated to polyethylene glycol (PEG) (DSPE-PEG) as a membrane anchoring domain. In such conjugates, DSPE-PEG may contain any suitable number of ethylene oxide units, for example, from 2 to about 500 ethylene oxide units. Specific examples include DSPE-PEG(1000), DSPE-PEG(2000) or DSPE-PEG(3000), but these are just a few examples. Alternatively, the phospholipid (sphingophospholipid or glycerophospholipid) may contain cholesterol as a membrane anchor domain. Cholesterol-based membrane anchor domains are described, for example, in Achalkumar et al, "Cholesterol-based anchors and tethers for phospholipid bilayers and for model biological membranes," Soft Matter, 2010, 6, 6036-6051.In exemplary embodiments, the linker portion of such membrane anchor domains may comprise from 1 to about 550 main chain atoms, from 1 to about 500 main chain atoms, from 1 to about 450 main chain atoms, from 1 to about 350 main chain atoms, from 1 to about 300 main chain atoms, from 1 to about 250 main chain atoms, from 1 to about 200 main chain atoms, from 1 to about 150 main chain atoms, from 1 to about 100 main chain atoms, from 1 to about 50 main chain atoms, from 1 to about 30 main chain atoms, from 1 to about 20 main chain atoms, from 1 to about 15 main chain atoms, or from 1 to about 12 main chain atoms, or from 1 to about 10 main chain atoms, where a main chain atom is a carbon atom optionally replaced with one or more heteroatoms selected from the group consisting of N, O, P, and S.

[0105] In the present invention, any kind of polymersome can be used as long as it can function as a carrier for the associated antigen or adjuvant. The polymersome can be an oxidation-sensitive polymersome, for example as described in Stano et al. "Tunable T cell immunity towards a protein antigen using polymersomes vs. solid-core nanoparticles, Biomaterials 34 (2013): 4339-4346" or U.S. Patent No. 8,323,696 to Hubbel. Alternatively, the polymersome can be insensitive to oxidation. Regardless of chemical stability (including the possibility of being sensitive or insensitive to oxidation), in the present invention, a polymersome is a vesicle with a polymer membrane, which is typically formed by self-assembly of a dilute solution of one or more amphiphilic block copolymers, which can be of various types, such as diblock and triblock (ABA or ABC), but not necessarily. The polymersome of the present invention can also be formed of tetrablock or pentablock copolymers. In the case of triblock copolymers, the central block is often shielded from the environment by its neighboring blocks, whereas diblock copolymers self-assemble into bilayers with two hydrophobic blocks arranged tail-to-tail to achieve much the same effect. In most cases, the vesicle membrane has an insoluble middle layer and a soluble outer layer. The driving force for the self-assembly of polymersome formation is believed to be the microphase separation of the insoluble blocks, which tend to associate to shield themselves from contact with water. The polymersomes of the present invention have remarkable properties due to the large molecular weight of the constituent copolymers. Increasing the total molecular weight of the block copolymers favors vesicle formation. As a result, the diffusion of (polymeric) amphiphiles is extremely low compared to vesicles formed by lipids and surfactants. Due to this low mobility of polymer chains aggregated into vesicle structures, it is possible to obtain stable polymersome morphologies.Unless otherwise stated, the terms "polymersome" and "vesicle" used herein are interpreted as similar and can be used interchangeably.Importantly, the polymersome of the present invention can be formed from one type of block copolymer or from two or more types of block copolymer.That is, the polymersome can be formed from a mixture of polymersomes and thus can contain two or more types of block copolymer.In some aspects, the polymersome of the present invention is oxidatively stable.

[0106] In some aspects, the present invention relates to a method for eliciting an immune response against a soluble (e.g., solubilized) encapsulated antigen in a subject. The method is suitable for injecting a composition comprising a polymersome (e.g., carrier or vehicle) having a membrane (e.g., surrounding membrane) of an amphiphilic polymer into a subject. The composition comprises a soluble (e.g., solubilized) antigen encapsulated by the membrane (e.g., surrounding membrane) of an amphiphilic polymer of the polymersome of the present invention. The antigen can be one or more of the following: (i) a polypeptide, (ii) a carbohydrate, (iii) a polynucleotide (e.g., the polynucleotide is not an antisense oligonucleotide, preferably the polynucleotide is a DNA molecule or a messenger RNA (mRNA) molecule), or a combination of (i) and / or (ii) and / or (iii).

[0107] In some further aspects, the invention relates to polymersomes capable of eliciting a CD8(+) T cell-mediated immune response.

[0108] In some aspects, the present invention relates to polymersomes capable of targeting lymph node resident macrophages and / or B cells. Exemplary non-limiting targeting mechanisms envisioned by the present invention include (i) delivery of encapsulated antigens (such as polypeptides) to dendritic cells (DCs) for T cell activation (CD4 and / or CD8). Another mechanism is (ii) delivery of whole folded antigens (such as proteins) that will be routed to DCs and also trigger titers (B cells).

[0109] In some aspects, the present invention relates to polymersomes encapsulating an antigen selected from the group consisting of: (i) an autoantigen, (ii) a non-self antigen, (iii) a non-self immunogen, and (iv) an autoimmunogen. Thus, the products and methods of the present invention are suitable for use in the context of induced tolerance (e.g., in clinical settings), for example, to target autoimmune diseases.

[0110] In some aspects, the present invention relates to polymersomes of the present invention comprising lipid polymers.

[0111] The polymersomes of the present invention may be co-encapsulated (i.e., in addition to the antigen) with one or more adjuvants, including synthetic oligodeoxynucleotides (ODNs) containing unmethylated CpG motifs that can trigger cells expressing Toll-like receptor 9 (including human plasmacytoid dendritic cells and B cells) to initiate an innate immune response characterized by the production of Th1 and proinflammatory cytokines, cytokines such as interleukin-1, interleukin-2, or interleukin-12, keyhole limpet hemocyanin (KLH), serum albumin, bovine thyroglobulin, or soybean trypsin inhibitor, to name just a few.

[0112] The polymersomes of the present invention can be of any size as long as the polymersomes are capable of eliciting an immune response. For example, the polymersomes may have a diameter of more than 70 nm. The diameter of the polymersomes may range from about 100 nm to about 1 μm, or from about 100 nm to about 750 nm, or from about 100 nm to about 500 nm. The diameter of the polymersomes may further range from about 125 nm to about 175 nm, or from about 125 nm to about 250 nm, from about 140 nm to about 240 nm, from about 150 nm to about 235 nm, from about 170 nm to about 230 nm, or from about 220 nm to about 180 nm, or from about 190 nm to about 210 nm. The diameter of the polymersomes may be, for example, about 200 nm, about 205 nm, or about 210 nm. When used as a (first and second) population to elicit an immune response, the population of polymersomes is typically a monodisperse population. The average diameter of the population of polymersomes used is typically greater than 70 nm, or greater than 120 nm, or greater than 125 nm, or greater than 130 nm, or greater than 140 nm, or greater than 150 nm, or greater than 160 nm, or greater than 170 nm, or greater than 180 nm, or greater than 190 nm (see also FIG. 2 in this respect). The average diameter of the population of polymersomes may be, for example, in the range of the individual polymersomes mentioned above. That is, the average diameter of the population of polymersomes may be in the range of 100 nm to about 1 μm, or in the range of about 100 nm to about 750 nm, or in the range of about 100 nm to about 500 nm, or in the range of about 125 nm to about 250 nm, about 140 nm to about 240 nm, about 150 nm to about 235 nm, about 170 nm to about 230 nm, or about 220 nm to about 180 nm, or about 190 nm to about 210 nm. The average diameter of a population of polymersomes may be, for example, about 200 nm, about 205 nm, or about 210 nm. The diameter can be determined, for example, by a dynamic light scattering (DLS) instrument using the preferred DLS parameter Z-average (d, nm). The Z-average size is the intensity weighted harmonic mean particle diameter (see Examples 1 and 2).In this context, it should be noted that according to US Patent No. 8,323,696 to Hubbel et al., polymersome aggregates / populations should have an average diameter of less than 70 nm in order to be able to induce an immune response. Similarly, Stano et al., 2013, supra, would have preferred to use smaller polymersomes, but due to technical limitations used polymersomes with a diameter of 125 nm ± 15 nm to induce an immune response. Thus, it is surprising that polymersome aggregates / populations of the invention, for example with an average diameter of more than 150 nm, are able to induce both cellular and humoral immune responses (see Examples). Such polymersome aggregates may be in a form suitable for inducing an immune response, for example by injection or oral administration.

[0113] In some aspects, the present invention relates to compositions of the present invention suitable for intradermal, intraperitoneal, subcutaneous, intravenous, or intramuscular injection or non-invasive administration, such as oral or inhaled or nasal administration, of the antigen of the present invention. The composition may comprise a polymersome (e.g., a carrier) of the present invention having a membrane (e.g., a surrounding membrane) of an amphiphilic polymer. The composition further comprises a soluble (e.g., solubilized) antigen encapsulated by the membrane of the amphiphilic polymer of the polymersome. The compositions of the present invention can be used for therapeutic purposes (e.g., treating a diseased subject or preventing disease, such as by vaccination), or can be used for antibody discovery, vaccine discovery, or targeted delivery.

[0114] In some aspects, the polymersomes of the invention have hydroxyl groups on their surface. In some further aspects, the polymersomes of the invention have no hydroxyl groups on their surface.

[0115] In the context of this application, the term "encapsulated" means surrounded by a membrane (e.g., the membrane of a polymersome of the invention) (e.g., contained within the lumen of the polymersome). The term "encapsulated" in reference to an antigen further means that the antigen is not incorporated, covalently attached, or conjugated to a membrane (e.g., the membrane of a polymersome of the invention). In reference to the compartmentalization of the polymersome vesicle structures described herein, the term "encapsulated" means that the inner vesicle is completely contained within the outer vesicle and surrounded by the vesicle membrane of the outer vesicle. The closed space surrounded by the vesicle membrane of the outer vesicle forms one compartment. The closed space surrounded by the vesicle membrane of the inner vesicle forms another compartment.

[0116] In the context of this application, the term "antigen" refers to any substance that can be specifically bound by immune system components. Only antigens that are capable of eliciting (or eliciting or inducing) an immune response are considered immunogenic and are called "immunogens." Exemplary, non-limiting antigens are polypeptides derived from the soluble portion of a protein, hydrophobic polypeptides that have been made soluble for inclusion, and aggregated polypeptides that are soluble as aggregates. Antigens can originate from within the body ("self-antigens") or from the external environment ("non-self").

[0117] Membrane proteins form a class of antigens that typically generate low levels of immune response. Of particular interest, soluble (e.g., solubilized) membrane proteins (MPs) as well as membrane-associated peptides (MAPs) and fragments (i.e., portions) thereof (e.g., antigens as referred to herein) can be encapsulated by polymersomes, which allows them to fold in a physiologically meaningful manner. This strongly boosts the immunogenicity of such antigens, so that a smaller amount of the corresponding antigen can be used to generate the same level of immune response when compared to free antigen. Furthermore, the large size of polymersomes (compared to free membrane proteins) allows them to be more easily detected by the immune system.

[0118] For purposes of this application, the term "B16 peptide" refers to any neo-antigen polypeptide derived from a spontaneous C57BL / 6-derived B16 melanoma model (e.g., the B16-F10 melanoma mouse model), non-limiting examples of which include peptides of SEQ ID NOs:9, 10, and 11.

[0119] For purposes of this application, the term "MC38 peptide" refers to any neo-antigen polypeptide derived from the MC38 mouse model of colon cancer, including, but not limited to, the peptides of SEQ ID NOs: 1, 2, and 3.

[0120] For purposes of this application, the term "influenza hemagglutinin (HA)" refers to a glycoprotein found on the surface of influenza viruses. HA has at least 18 different antigens, all of which are within the scope of the present invention. These subtypes are designated H1 through H18. Non-limiting examples of "influenza hemagglutinin (HA)" subtype H1 include the polypeptides of SEQ ID NOs:5, 6, 7, and 8.

[0121] As used herein, the term "swine influenza hemagglutinin (HA)" refers to a glycoprotein found on the surface of swine influenza viruses, a family of influenza viruses specific to pigs. A non-limiting example of a "swine influenza hemagglutinin (HA)" is subtype H1 of SEQ ID NO:6.

[0122] In the context of this application, the term "coronavirus" refers to viruses of the subfamily Coronaviridae, a family of enveloped, positive-sense, single-stranded RNA viruses. Coronaviruses can cause disease in mammals and birds. There are four genera in this subfamily: Alphacoronavirus, Betacoronavirus, Gammacoronavirus, and Deltacoronavirus. In humans, coronaviruses can cause respiratory tract infections, which can be mild or fatal, such as SARS, MERS, and COVID-19. Human pathogenic coronaviruses generally belong to the Alphacoronavirus or Betacoronavirus genera. Viruses belonging to the Alphacoronavirus genus include, for example, PEDv, transmissible gastroenteritis virus (TGEV), feline coronavirus (FCoV), including feline enteric coronavirus (FECV) and feline infectious peritonitis virus (FIPV), canine coronavirus (CCoV), or human pathogenic coronaviruses such as human coronavirus 229E (HCoV-229E) and human coronavirus NL63 (HCoV-NL63). Within the genus Betacoronavirus, the subgenera Sarbecovirus and Merbecovirus are most relevant to the present disclosure, and include the species SARS-CoV-1, SARS-CoV-2, and MERS-CoV. Other human pathogenic Betacoronaviruses are Human Coronavirus OC43 (HCoV-OC43), Human Coronavirus HKU1 (HCoV-HKU1). Human pathogenic coronaviruses are reviewed in Corman VM, Muth D, Niemeyer D, Drosten C., Hosts and Sources of Endemic Human Coronaviruses. Adv Virus Res. 2018;100:163-188.

[0123] For the purposes of this application, the term "spike protein" refers to a glycoprotein present on the surface of the viral capsid or viral envelope. The spike protein binds to certain receptors on the host cell and is therefore important for both host specificity and viral infectivity.

[0124] In the context of this application, the term "PEDv S protein" refers to the spike glycoprotein present on the surface of the porcine epidemic diarrhea virus (PEDV), a family of coronaviruses in pigs. Non-limiting examples of soluble "PEDv S protein" that may be used herein include the entire soluble fragment of the porcine epidemic diarrhea virus (PEDv) spike protein (S protein) (UniProtKB Accession No. V5TA78) consisting of the S1 and S2 regions having the amino acid sequence of SEQ ID NO: 12, the soluble fragment of the S1 region of SEQ ID NO: 13, or the soluble fragment of the S2 region of SEQ ID NO: 14. It is of course possible to use shorter fragments of the entire soluble fragment of the S1 and S2 regions, or only of either the S1 or S2 regions (see FIG. 12 in this regard). It is of course possible to use fragments containing part of S1 and part of S2 in the polymersomes of the invention, for example amino acids 500 to 939 of the deposited sequence of the spike protein. It is also noted that the polymersomes of the invention may encapsulate one or more different soluble fragments of the spike protein, such as the entire S1 region, the S2 region, and / or the entire S1 and S2 regions. In exemplary embodiments of the polymersomes of the invention, the polymersomes of the invention encapsulate therein one type of soluble fragment (e.g., only the S1 region), two different types of soluble fragments (e.g., the S1 and S2 regions), three different types of soluble fragments (the S1 region, the S2 region, and the entire soluble fragment of S1 and S2 of SEQ ID NO:12 (amino acid residues 19-1327)), or even four different types of fragments (e.g., the S1 region, the S2 region, and the entire soluble fragment of S1 and S2 of SEQ ID NO:12 (amino acid residues 19-1327), and a fourth type of fragment as described above that contains a portion of S1 and a portion of S2, e.g., amino acids 500-939 of the spike protein sequence).It should also be noted here that the polymersomes of the present invention encapsulating one or more different soluble fragments of the spike protein are used in a preferred embodiment as oral vaccines against porcine epidemic diarrhea virus.

[0125] For purposes of this application, the term "MERS-CoV S protein" or "MERS-CoV spike protein" refers to the spike glycoprotein present on the surface of the human pathogenic coronavirus, Middle East Respiratory Syndrome-associated coronavirus (MERS-CoV). The MERS-CoV spike protein of the present disclosure has the sequence set forth in UniProtKB Accession No.: K0BRG7 version 40 on Feb. 26, 2020 (GenBank Accession No. AFS88936, version AFS88936.1) or SEQ ID NO: 42. Non-limiting examples of soluble "MERS-CoV S proteins" that may be used in the present invention include the entire soluble fragment of the S1 and S2 regions of the MERS-CoV spike protein (S protein), which may correspond to amino acids 1-1297 of the MERS-CoV spike protein or have the amino acid sequence set forth in SEQ ID NO: 43. A non-limiting example of a soluble "MERS-CoV S protein" that may be used in the present invention is the S1 region, which corresponds to amino acids 18-725 of the MERS-CoV spike protein (S protein) or has the amino acid sequence of SEQ ID NO: 44. A non-limiting example of a soluble "MERS-CoV S protein" that may be used in the present invention is a soluble fragment of the S2 region, which may correspond to amino acids 726-1296 of the MERS-CoV spike protein (S protein) or has the amino acid sequence of SEQ ID NO: 45. It is of course possible to use shorter fragments of the entire S1 and S2 regions, or of either the S1 region or the S2 region alone, for example a fragment may include the receptor binding domain (RBD), which corresponds to amino acids 377-588 of the MERS-CoV spike protein or has the amino acid sequence of SEQ ID NO: 46. It is also noted herein that the polymersomes of the present invention may encapsulate one or more different soluble fragments of the spike protein, such as the S1 region, the S2 region, or soluble fragments thereof, the entire soluble fragments of the S1 and S2 regions, and / or the RBD.In exemplary embodiments of the polymersomes of the invention, the polymersomes of the invention have encapsulated therein one type of soluble fragment (e.g., only the entire soluble fragment of the S1 and S2 regions), two different types of soluble fragments (e.g., the entire soluble fragment of the S1 and S2 regions and the entire S1 region or a soluble fragment of the S2 region), three different types of soluble fragments (the S1 region, a soluble fragment of the S2 region, and the entire soluble fragment of S1 and S2 of SEQ ID NO:42 (amino acid residues 1-1297)), or even four different types of fragments (e.g., the S1 region, a soluble fragment of the S2 region, the entire soluble fragment of S1 and S2 of SEQ ID NO:42 (amino acid residues 1-1297), and a fourth type, the RBD). In a preferred embodiment, the polymersomes of the invention have encapsulated therein a soluble fragment that comprises, consists essentially of, or consists of the S1 region corresponding to amino acid residues 18-725 of the full-length MERS-CoV spike protein. In a preferred embodiment, the polymersomes of the invention have encapsulated therein a soluble fragment comprising, consisting essentially of, or consisting of a soluble fragment of the S2 region corresponding to amino acid residues 726-1296 of the full-length MERS-CoV spike protein. In a preferred embodiment, the polymersomes of the invention have encapsulated therein a soluble fragment comprising, consisting essentially of, or consisting of the S1 and S2 regions corresponding to amino acid residues 1-1297 of the full-length MERS-CoV spike protein. In a preferred embodiment, the polymersomes of the invention have encapsulated therein a fragment comprising, consisting essentially of, or consisting of the S1 and S2 regions corresponding to amino acid residues 1-1327 of the full-length MERS-CoV spike protein.In this context, "consisting essentially of" means that the N-terminal and / or C-terminal points of the fragment may vary within a limited range, for example by up to 25 amino acid positions, for example by up to 20 amino acid positions, for example by up to 15 amino acid positions, up to 10 amino acid positions, up to 5 amino acid positions, up to 4 amino acid positions, up to 3 amino acid positions, up to 2 amino acid positions, or up to 1 amino acid position. In one specific example, a fragment consisting essentially of amino acids 726-1296 of the full-length MERS-CoV spike protein may consist of amino acids 716-1296, 736-1296, 726-1286, or 726-1306, 716-1286, 736-1286, 736-1306, or 716-1306 of the full-length MERS-CoV spike protein.

[0126] The MERS-CoV spike protein of the present disclosure may also include variants of the above-mentioned sequences. These variants include natural variants of other isolates of MERS-CoV, as well as artificial modifications that may be introduced into the sequence of the MERS-CoV S protein. In one specific example, mutations may be introduced to alter the formation of the expressed protein. For this purpose, the furin cleavage site located at positions 754-757 of SEQ ID NO:42 may be mutated. Reduction of post-expression cleavage may be achieved by reducing the basicity of this amino acid sequence. For example, residues arginine 754 and / or 757 may be mutated to a less basic amino acid, such as glycine (position numbers correspond to the amino acid sequence shown in SEQ ID NO:42) or other less basic amino acids. Thus, a furin cleavage site with a native sequence of RSVR (SEQ ID NO:58) may be mutated to GSVG (SEQ ID NO:59). Further modifications may include the addition of a trimerization domain, preferably to the C-terminus of the protein, which may help increase the native fold of the S1 and / or S2 domains. Such trimerization domains may include a Foldon domain (e.g., SEQ ID NO:54), a GCN4-based trimerization domain (e.g., SEQ ID NO:55 or SEQ ID NO:56), or other motifs known to those of skill in the art. Additionally, secretion leader sequences may be added to the N-terminus of the protein, which may improve production and / or subsequent processing, such as isolation and purification. One specific example of such a leader sequence is the honeybee melittin leader sequence (SEQ ID NO:57). Other useful leader sequences are known to those of skill in the art. Thus, the soluble fragments of the spike protein of the present disclosure also include high identity variants of the specific sequences of the soluble fragments of the spike protein explicitly or implicitly disclosed herein.For example, variants having at least about 95%, at least about 96%, at least about 97%, at least about 98%, or at least about 99% sequence identity to a soluble fragment of the spike protein of the disclosure, particularly a soluble fragment of the MERS-CoV S protein of the disclosure. In one specific example, a soluble fragment of the S fragment of the disclosure can comprise, consist essentially of, or consist of a sequence having at least about 95%, at least about 96%, at least about 97%, at least about 98%, or at least about 99% sequence identity to a sequence selected from the group consisting of SEQ ID NOs:43-46.

[0127] Alternatively or additionally, the polymersomes of the present disclosure may encapsulate one or more nucleic acids, such as mRNA, self-amplifying mRNA, DNA encoding one or more MERS-CoV spike proteins of the present disclosure or soluble fragments thereof.

[0128] It is also noted here that in a preferred embodiment, the polymersomes of the invention encapsulating one or more different soluble fragments of the MERS-CoV spike protein and / or nucleic acids encoding same or full-length MERS-CoV spike protein are used as vaccines against human diseases, in particular infections caused by human pathogenic coronaviruses, in particular Middle East Respiratory Syndrome (MERS). Thus, the polymersomes of the invention encapsulating one or more different soluble fragments of the MERS-CoV spike protein and / or nucleic acids encoding same or full-length MERS-CoV spike protein may be used to treat (including prevent) fever, cough, sputum, shortness of breath, pneumonia and / or acute respiratory distress syndrome (ARDS).

[0129] In a preferred embodiment, the polymersomes of the present invention encapsulating one or more different soluble fragments of MERS-CoV spike protein and / or nucleic acid encoding same or full-length MERS-CoV spike protein are administered intramuscularly.In a preferred embodiment, the polymersomes of the present invention encapsulating one or more different soluble fragments of MERS-CoV spike protein and / or nucleic acid encoding same or full-length MERS-CoV spike protein are administered intranasally.In a preferred embodiment, the polymersomes of the present invention encapsulating one or more different soluble fragments of MERS-CoV spike protein and / or nucleic acid encoding same or full-length MERS-CoV spike protein are administered by inhalation.

[0130] For purposes of this application, the term "SARS-CoV-2 S protein" or "SARS-CoV-2 spike protein" refers to the spike glycoprotein present on the surface of the human pathogenic coronavirus, Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). The SARS-CoV-2 spike protein of this disclosure has the sequence set forth in UniProtKB Accession No.: P0DTC2 Version 1 on April 22, 2020 (GenBank Accession No. MN908947, Version MN908947.3) or SEQ ID NO:19. Non-limiting examples of soluble "SARS-CoV-2 S proteins" that can be used in the present invention include the entire soluble fragment of the S1 and S2 regions of the SARS-CoV-2 spike protein (S protein) corresponding to amino acids 16-1213, 14-1204, or 19-1204 of the SARS-CoV-2 spike protein, or having the amino acid sequence shown in SEQ ID NO:34, SEQ ID NO:35, or SEQ ID NO:65. Non-limiting examples of soluble "SARS-CoV-2 S proteins" that can be used in the present invention also include the S1 region corresponding to amino acids 16-685 of the SARS-CoV-2 spike protein (S protein), or having the amino acid sequence of SEQ ID NO:37. Non-limiting examples of soluble "SARS-CoV-2 S proteins" that can be used in the present invention also include the S2 region, which corresponds to amino acids 686-1213 or 646-1204 of the SARS-CoV-2 spike protein (S protein), or has the amino acid sequence of SEQ ID NO: 38 or SEQ ID NO: 39. It is of course also possible to use shorter fragments of the entire soluble fragments of the S1 and S2 regions, or of either the S1 or S2 regions alone, such as the amino acid sequence of 318-524 of the SARS-CoV-2 protein (SEQ ID NO: 41, see in this regard FIG. 23A) as the receptor binding domain.In one embodiment, the shorter fragment of the S2 region comprises, consists essentially of, or consists of amino acids corresponding to positions 686-1204 of SEQ ID NO:19. In one embodiment, the soluble fragment of the spike protein comprises, consists essentially of, or consists of amino acids corresponding to positions 646-1204 of SEQ ID NO:19. In one embodiment, the soluble fragment of the spike protein comprises, consists essentially of, or consists of a sequence set forth in any of SEQ ID NOs:34-36 and SEQ ID NO:65. It is also noted herein that the polymersomes of the present invention may encapsulate one or more different soluble fragments of the spike protein, such as the S1 region or fragments thereof, the S2 region or fragments thereof, and / or fragments thereof that include the entire S1 and S2 regions or portions of the S1 and S2 regions. In exemplary embodiments of the polymersomes of the invention, the polymersomes of the invention have encapsulated therein one type of soluble fragment (e.g., only the S1 region or a fragment thereof), two different types of soluble fragments (e.g., the S1 and S2 regions or fragments of the S1 and / or S2 regions), three different types of soluble fragments (the S1 region or a fragment thereof, the S2 region or a fragment thereof, and the entire soluble fragment of S1 and S2 of SEQ ID NO:19, as well as four different types of fragments (e.g., the S1 region or a fragment thereof, the S2 region or a fragment thereof, the entire soluble fragment of S1 and S2 of SEQ ID NO:19 or a fragment thereof comprising a portion of the S1 region and a portion of the S2 region, and as a fourth type, a fragment as described above that contains a portion of S1 and a portion of S2, e.g., amino acids 14-1204 of the spike protein sequence).

[0131] Variants of the SARS-CoV-2 S protein may be identified, for example, by GeneBank Accession No. QII57278.1 (SEQ ID NO:20), GeneBank Accession No. YP_009724390.1 (SEQ ID NO:21), GeneBank Accession No. QIO04367.1 (SEQ ID NO:22), GeneBank Accession No. QHU79173.2 (SEQ ID NO:23), GeneBank Accession No. QII87830.1 (SEQ ID NO:24), GeneBank Accession No. QIA98583.1 (SEQ ID NO:25), GeneBank Accession No. QIA20044.1 (SEQ ID NO:26), GeneBank Accession No. QIK50427.1 (SEQ ID NO:27), GeneBank Accession No. QHR84449.1 (SEQ ID NO:28), GeneBank Accession No. QHR84449.1 (SEQ ID NO:29), GeneBank Accession No. QHR84449.1 (SEQ ID NO:30), GeneBank Accession No. QHR84449.1 (SEQ ID NO:31), GeneBank Accession No. QHR84449.1 (SEQ ID NO:32), GeneBank Accession No. QHR84449.1 (SEQ ID NO:33), GeneBank Accession No. QHR84449.1 (SEQ ID NO:34), GeneBank Accession No. QHR84449.1 (SEQ ID NO:35), GeneBank Accession No. QHR84449.1 (SEQ ID NO:36), GeneBank Accession No. QHR84449.1 (SEQ ID NO:37), GeneBank Accession No. QHR84449.1 (SEQ ID NO:38), GeneBank Accession No. QHR84449.1 (SEQ ID NO:39), GeneBank Accession Several variants are known in the art, including SEQ ID NO:28), GeneBank Accession No. QIQ08810.1 (SEQ ID NO:29), GeneBank Accession No. QIJ96493.1 (SEQ ID NO:30), GeneBank Accession No. QIC53204.1 (SEQ ID NO:31), GeneBank Accession No. QHZ00379.1 (SEQ ID NO:32), and GeneBank Accession No. QHS34546.1 (SEQ ID NO:33). Compared to SEQ ID NO:19, these variants can have mutations at sequence positions corresponding to 28, 49, 74, 145, 157, 181, 221, 307, 408, 528, 614, 655, 797, and 930. Further modifications can be introduced into the sequence of the SARS-CoV-2 S protein. In one embodiment, mutations can be introduced to alter the formation of the expressed protein. For this purpose, the furin cleavage site located at positions 679-685 of SEQ ID NO:19 can be mutated. Reduction of post-expression cleavage can be achieved by reducing the basicity of this amino acid sequence.For example, residues Pro681, Arg682 and / or Arg683 may be mutated to less basic amino acids, such as Pro681→Asn, Arg682→Gln and / or Arg683→Ser (position numbers correspond to the amino acid sequence shown in SEQ ID NO:19) or other less basic amino acids. Thus, a furin cleavage site with a native sequence of NSPRRAR (SEQ ID NO:52) may be mutated to a sequence of NSNQSAR (SEQ ID NO:53). An example of a soluble fragment of a SARS-CoV-2 spike protein with a mutant furin cleavage site is shown in SEQ ID NO:65. An example of a SARS-CoV-2 spike protein with a mutant furin cleavage site is shown in SEQ ID NO:66. Further modifications may include the addition of a trimerization domain, preferably at the C-terminus of the protein, which may help increase the native fold of the S1 and / or S2 domains. Such trimerization domains include the Foldon domain (see, for example, Guethe et al., J. Mol. Biol. (2004) 337, 905-915). TIFF0007676030000001.tif4128), including GCN4-based trimerization domains and immunosilenced variants thereof (e.g., as described in Sliepen et al. J. Biol. Chem. (2015) 290(12):7436-7442). TIFF0007676030000002.tif11166), or other motifs known to those skilled in the art. Additionally, secretory leader sequences may be added to the N-terminus of the protein, which may improve production and / or subsequent processing, such as isolation and purification. One specific example of such a leader sequence is the honeybee melittin leader sequence. TIFF0007676030000003.tif4128. Other useful leader sequences are known to those of skill in the art. Thus, the soluble fragments of the spike protein of the present disclosure also include highly identical variants of the specific sequences of the soluble fragments of the spike protein as explicitly or implicitly disclosed herein. For example, variants having at least about 95%, at least about 96%, at least about 97%, at least about 98%, or at least about 99% sequence identity to the soluble fragments of the spike protein of the present disclosure, particularly to the soluble fragments of the SARS-CoV-2 S protein of the present disclosure. In one embodiment, a soluble fragment of the S fragment of the present disclosure can comprise, consist essentially of, or consist of a sequence having at least about 95%, at least about 96%, at least about 97%, at least about 98%, or at least about 99% sequence identity to a sequence selected from the group consisting of positions 16-1213, 16-685, 686-1213, 686-1204, 646-1204, or 14-1204 of SEQ ID NO: 19 (SARS-CoV-2 spike protein). In another embodiment, a soluble fragment of the S fragment of the present disclosure can have a sequence having at least about 95%, at least about 96%, at least about 97%, at least about 98%, or at least about 99% sequence identity to a sequence selected from the group consisting of SEQ ID NO: 34-41 and SEQ ID NO: 65.

[0132] In a preferred embodiment, the polymersomes of the invention have encapsulated therein a soluble fragment comprising, consisting essentially of, or consisting of an S1 region corresponding to amino acid residues 16-685 of the full-length SARS-CoV-2 spike protein as set forth in SEQ ID NO:19, or having the amino acid sequence of SEQ ID NO:37. In a preferred embodiment, the polymersomes of the invention have encapsulated therein a soluble fragment comprising, consisting essentially of, or consisting of an S2 region corresponding to amino acid residues 686-1213 of the full-length SARS-CoV-2 spike protein as set forth in SEQ ID NO:19, or having the amino acid sequence of SEQ ID NO:38. In a preferred embodiment, the polymersomes of the invention have encapsulated therein a soluble fragment comprising, consisting essentially of, or consisting of the S1 and S2 regions corresponding to amino acid residues 16-1213 of the full-length SARS-CoV-2 spike protein shown in SEQ ID NO:19, or having the amino acid sequence of SEQ ID NO:34. In a preferred embodiment, the polymersomes of the invention have encapsulated therein a soluble fragment comprising, consisting essentially of, or consisting of the amino acid sequence corresponding to amino acid residues 686-1204 of the full-length SARS-CoV-2 spike protein shown in SEQ ID NO:19. In a preferred embodiment, the polymersomes of the invention have encapsulated therein a soluble fragment comprising, consisting essentially of, or consisting of the amino acid sequence corresponding to amino acid residues 646-1204 of the full-length SARS-CoV-2 spike protein shown in SEQ ID NO:19, or having the amino acid sequence of SEQ ID NO:39. In a preferred embodiment, the polymersomes of the invention have encapsulated therein a soluble fragment that comprises, consists essentially of, or consists of an amino acid sequence corresponding to amino acid residues 14 to 1204 of the full-length SARS-CoV-2 spike protein as shown in SEQ ID NO:19, or has the amino acid sequence of SEQ ID NO:35.In a preferred embodiment, the polymersomes of the invention have encapsulated therein a soluble fragment that comprises, consists essentially of, or consists of an amino acid sequence corresponding to amino acid residues 19 to 1204 of the full-length SARS-CoV-2 spike protein as shown in SEQ ID NO:19, or has the amino acid sequence of SEQ ID NO:65. In a preferred embodiment, the polymersome of the invention encapsulates therein a soluble fragment that comprises, consists essentially of, or consists of a sequence having at least about 95%, at least about 96%, at least about 97%, at least about 98%, or at least about 99% sequence identity to a sequence selected from the group consisting of sequences corresponding to positions 16-1213, 16-685, 686-1213, 686-1204, 646-1204, 14-1204, or 19-1204 of SEQ ID NO:19 (SARS-CoV-2 spike protein). In a preferred embodiment, the polymersomes of the invention encapsulate therein a soluble fragment that comprises, consists essentially of, or consists of a sequence having at least about 95%, at least about 96%, at least about 97%, at least about 98%, or at least about 99% sequence identity to a sequence selected from the group consisting of SEQ ID NO: 36, 40, and / or 65. In this context, "consisting essentially of" means that the N-terminal and / or C-terminal points of the fragment may vary within a limited range, for example by up to 25 amino acid positions, for example by up to 20 amino acid positions, for example by up to 15 amino acid positions, up to 10 amino acid positions, up to 5 amino acid positions, up to 4 amino acid positions, up to 3 amino acid positions, up to 2 amino acid positions, or up to 1 amino acid position. In one embodiment, a fragment consisting essentially of amino acids 646 to 1204 of the full-length SARS-CoV-2 spike protein can consist of amino acids 641 to 1204, 651 to 1204, 646 to 1209, or 646 to 1199, 641 to 1209, or 651 to 1199 of the full-length SARS-CoV-2 spike protein.

[0133] Alternatively or additionally, the polymersomes of the present disclosure may encapsulate one or more nucleic acids, such as mRNA, self-amplifying mRNA, DNA encoding one or more SARS-CoV-2 spike proteins or soluble fragments thereof of the present disclosure.

[0134] It is also noted herein that in a preferred embodiment, the polymersomes of the invention encapsulating one or more different soluble fragments of the SARS-CoV-2 spike protein and / or nucleic acids encoding same are used as vaccines against human diseases, in particular infections caused by human pathogenic coronaviruses, coronavirus disease 2019 (COVID-19). Thus, the polymersomes of the invention encapsulating one or more different soluble fragments of the SARS-CoV-2 spike protein and / or nucleic acids encoding same may be used to treat (including prevent) fever, cough, shortness of breath, pneumonia, organ failure, acute respiratory distress syndrome (ARDS), fatigue, muscle pain, diarrhea, sore throat, loss of smell and / or abdominal pain.

[0135] In a preferred embodiment, the polymersomes of the invention encapsulating one or more different soluble fragments of the SARS-CoV-2 spike protein and / or a nucleic acid encoding same or the full-length SARS-CoV-2 spike protein are administered intramuscularly. In a preferred embodiment, the polymersomes of the invention encapsulating one or more different soluble fragments of the SARS-CoV-2 spike protein and / or a nucleic acid encoding same or the full-length SARS-CoV-2 spike protein are administered intranasally. In a preferred embodiment, the polymersomes of the invention encapsulating one or more different soluble fragments of the SARS-CoV-2 spike protein and / or a nucleic acid encoding same or the full-length SARS-CoV-2 spike protein are administered by inhalation.

[0136] For purposes of this application, the term "SARS-CoV-1 S protein" or "SARS-CoV-1 spike protein" refers to the spike glycoprotein present on the surface of the human pathogenic coronavirus Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV or SARS-CoV-1). The SARS-CoV-1 spike protein of the present disclosure has the sequence set forth in UniProtKB Accession No.: P59594 version 134 on December 11, 2019 or SEQ ID NO: 48. Non-limiting examples of soluble "SARS-CoV-1 S proteins" that may be used in the present invention include the entire soluble fragment of the S1 and S2 regions of the SARS-CoV-1 spike protein (S protein), which may correspond to amino acids 14-1195 of the SARS-CoV-1 spike protein or have the amino acid sequence set forth in SEQ ID NO: 48. A non-limiting example of a soluble "SARS-CoV-1 S protein" that may be used in the present invention is the S1 region, which corresponds to positions 14-667 of the SARS-CoV-1 spike protein (S protein) or has the amino acid sequence of SEQ ID NO: 49. A non-limiting example of a soluble "SARS-CoV-1 S protein" that may be used in the present invention is a soluble fragment of the S2 region, which may correspond to positions 668-1198 of the SARS-CoV-1 spike protein (S protein) or has the amino acid sequence of SEQ ID NO: 50. It is of course possible to use shorter fragments of the entire S1 and S2 regions, or of either the S1 region or the S2 region alone, for example a fragment may include the receptor binding domain (RBD), which corresponds to positions 306-527 of the SARS-CoV-1 spike protein or has the amino acid sequence of SEQ ID NO: 51. It is also noted herein that the polymersomes of the present invention may encapsulate one or more different soluble fragments of the spike protein, such as the S1 region, the S2 region, or soluble fragments thereof, the entire soluble fragments of the S1 and S2 regions, and / or the RBD.In exemplary embodiments of the polymersomes of the invention, the polymersomes of the invention have encapsulated therein one type of soluble fragment (e.g., only the entire soluble fragment of the S1 and S2 regions), two different types of soluble fragments (e.g., the entire soluble fragment of the S1 and S2 regions and the entire S1 region or a soluble fragment of the S2 region), three different types of soluble fragments (a soluble fragment of the S1 region, a soluble fragment of the S2 region, and the entire soluble fragment of S1 and S2 of SEQ ID NO:47 (amino acid residues 14-1195)), or even four different types of fragments (e.g., a soluble fragment of the S1 region, a soluble fragment of the S2 region, the entire soluble fragment of S1 and S2 of SEQ ID NO:47 (amino acid residues 14-1195), and a fourth type, the RBD). In a preferred embodiment, the polymersomes of the invention have encapsulated therein a soluble fragment comprising, consisting essentially of, or consisting of an S1 region corresponding to amino acid residues 14-667 of the full-length SARS-CoV-1 spike protein. In a preferred embodiment, the polymersomes of the invention have encapsulated therein a soluble fragment comprising, consisting essentially of, or consisting of a soluble fragment of an S2 region corresponding to amino acid residues 668-1195 of the full-length SARS-CoV-1 spike protein. In a preferred embodiment, the polymersomes of the invention have encapsulated therein a soluble fragment comprising, consisting essentially of, or consisting of an S1 and S2 region corresponding to amino acid residues 14-1195 of the full-length SARS-CoV-1 spike protein. In a preferred embodiment, the polymersomes of the invention encapsulate therein fragments that comprise, consist essentially of, or consist of the S1 and S2 regions corresponding to amino acid residues 14 to 1255 of the full-length SARS-CoV-1 spike protein.In this context, "consisting essentially of" means that the N-terminal and / or C-terminal points of the fragment may vary within a limited range, for example by up to 25 amino acid positions, for example by up to 20 amino acid positions, for example by up to 15 amino acid positions, up to 10 amino acid positions, up to 5 amino acid positions, up to 4 amino acid positions, up to 3 amino acid positions, up to 2 amino acid positions, or up to 1 amino acid position.

[0137] The SARS-CoV-1 spike protein of the present disclosure may also include variants of the above-mentioned sequences. These variants include natural variants of other isolates of SARS-CoV-1, as well as artificial modifications that may be introduced into the sequence of the SARS-CoV-1 S protein. In one specific example, mutations may be introduced to alter the formation of the expressed protein. For this purpose, the furin cleavage site located at positions 761-767 of SEQ ID NO:47 may be mutated. Reduction of post-expression cleavage may be achieved by reducing the basicity of this amino acid sequence. For example, residues Arg764 and / or Arg767 may be mutated to a less basic amino acid, such as Gly (position numbers correspond to the amino acid sequence shown in SEQ ID NO:47) or other less basic amino acids. Thus, a furin cleavage site with a native sequence of EQDRNTR (SEQ ID NO:60) may be mutated to the sequence EQDGNTG (SEQ ID NO:61). Further modifications may include the addition of a trimerization domain, preferably to the C-terminus of the protein, which may help increase the native fold of the S1 and / or S2 domains. Such trimerization domains may include a Foldon domain (e.g., SEQ ID NO:54), a GCN4-based trimerization domain (e.g., SEQ ID NO:55 or SEQ ID NO:56), or other motifs known to those of skill in the art. Additionally, secretion leader sequences may be added to the N-terminus of the protein, which may improve production and / or subsequent processing, such as isolation and purification. One specific example of such a leader sequence is the honeybee melittin leader sequence (SEQ ID NO:57). Other useful leader sequences are known to those of skill in the art. Thus, the soluble fragments of the spike protein of the present disclosure also include high identity variants of the specific sequences of the soluble fragments of the spike protein explicitly or implicitly disclosed herein.For example, variants having at least about 95%, at least about 96%, at least about 97%, at least about 98%, or at least about 99% sequence identity to a soluble fragment of the spike protein of the present disclosure, particularly a soluble fragment of the SARS-CoV-1 S protein of the present disclosure. In one specific example, a soluble fragment of the S fragment of the present disclosure can comprise, consist essentially of, or consist of a sequence having at least about 95%, at least about 96%, at least about 97%, at least about 98%, or at least about 99% sequence identity to a sequence selected from the group consisting of SEQ ID NOs:48-51.

[0138] Alternatively or additionally, the polymersomes of the present disclosure may encapsulate one or more nucleic acids, such as mRNA, self-amplifying mRNA, DNA encoding one or more SARS-CoV-1 spike proteins or soluble fragments thereof of the present disclosure.

[0139] It is also noted here that in a preferred embodiment, the polymersomes of the invention encapsulating one or more different soluble fragments of the SARS-CoV-1 spike protein and / or nucleic acids encoding same or full-length SARS-CoV-1 spike protein are used as vaccines against human diseases, in particular infections caused by human pathogenic coronaviruses, in particular Severe Acute Respiratory Syndrome (SARS). Thus, the polymersomes of the invention encapsulating one or more different soluble fragments of the SARS-CoV-1 spike protein and / or nucleic acids encoding same or full-length SARS-CoV-1 spike protein may be used to treat (including prevent) fever, muscle pain, lethargy, cough, sore throat, shortness of breath, pneumonia and / or acute respiratory distress syndrome (ARDS).

[0140] In a preferred embodiment, the polymersomes encapsulating one or more different soluble fragments of the SARS-CoV-1 spike protein and / or the nucleic acid encoding same or the full-length SARS-CoV-1 spike protein are administered intramuscularly. In a preferred embodiment, the polymersomes of the invention encapsulating one or more different soluble fragments of the SARS-CoV-1 spike protein and / or the nucleic acid encoding same or the full-length SARS-CoV-1 spike protein are administered intranasally. In a preferred embodiment, the polymersomes of the invention encapsulating one or more different soluble fragments of the SARS-CoV-1 spike protein and / or the nucleic acid encoding same or the full-length SARS-CoV-1 spike protein are administered by inhalation.

[0141] In the context of this application, the term "oxidative stability" refers to a measure of the resistance of polymersomes (or corresponding polymers or membranes) to oxidation, using, for example, the method described by Scott et al., 2012. In this method, polymersomes with encapsulated antigens are incubated in a 0.5% solution of hydrogen peroxide, and the amount of free antigen (released) can be quantified by UV / fluorescence HPLC. Polymersomes that release a substantial portion or all of the encapsulated antigen under these oxidizing conditions are considered to be oxidation-sensitive. Another method for determining whether a block copolymer, and therefore the resulting polymersome, is oxidation-stable or oxidation-sensitive is described in column 16 of US Pat. No. 8,323,696. According to this method, polymers with oxidation-sensitive functional groups are chemically modified by a mild oxidizing agent, and the test is the enhanced solubility in 10% hydrogen peroxide in vitro for 20 hours. For example, poly(propylene sulfide) (PPS) is an oxidation-sensitive polymer (see, for example, Scott et al. 2012 supra and US Pat. No. 8,323,696). PPS can serve as a standard for determining whether the polymer of interest and each polymersome of interest are oxidation-susceptible or oxidation-stable. For example, if the same or more amount of antigen is released from the polymersome of interest, or about 90% or more, or about 80% or more, or about 70% or more, or about 60% or more, compared to the amount released from the PPS polymersome containing the same antigen, the polymersome is considered to be oxidation-susceptible. If the same or less amount of antigen is released from the polymersome of interest, less than about 0.5%, or less than about 1.0%, or less than about 2%, or less than about 5%, or less than about 10%, or less than about 20%, or less than about 30%, or less than about 40%, or less than about 50% compared to the amount released from the PPS polymersome containing the same antigen, the polymersome is considered to be oxidation-stable.In line with this, therefore, PPS polymersomes as described in US Pat. No. 8,323,696, or PPS-bl-PEG polymersomes, such as those made of poly(propylene sulfide) (PPS) and poly(ethylene glycol) (PEG) as components as described in Stano et al., are not oxidatively stable polymersomes in the sense of the present invention. Similarly, PPS30-PEG17 polymersomes are not oxidatively stable polymersomes in the sense of the present invention. Other non-limiting examples of oxidative stability measurements include measurements of stability in the presence of serum components (e.g., components of mammalian serum, e.g., human serum), or for example, measurements of stability inside endosomes.

[0142] For purposes of this application, the term "reductive stability" refers to a measure of a polymersome's resistance to reduction in a reducing environment.

[0143] As used herein, the term "serum" refers to plasma from which the clotting proteins have been removed.

[0144] For purposes of this application, the term "oxidation-independent release" refers to the release of polymersome contents without, or essentially without, oxidation of the polymer forming the polymersome.

[0145] The term "polypeptide" is used herein equivalently to the term "protein". Proteins (including fragments thereof, preferably biologically active fragments, and peptides, usually those having less than 30 amino acids) comprise one or more amino acids coupled together (resulting in a chain of amino acids) via covalent peptide bonds. The term "polypeptide" as used herein refers to a group of molecules, e.g., those consisting of more than 30 amino acids. Polypeptides can further form multimers, i.e., consisting of two or more polypeptide molecules, such as dimers, trimers and higher oligomers. The polypeptide molecules forming such dimers, trimers, etc. may or may not be identical. The corresponding higher order structures of such multimers are therefore called homodimers or heterodimers, homotrimers or heterotrimers, etc. An example of a heteromultimer is an antibody molecule, which in its native form consists of two identical light polypeptide chains and two identical heavy polypeptide chains. The terms "polypeptide" and "protein" also refer to naturally modified polypeptides / proteins, where the modification is achieved by post-translational modifications such as, for example, glycosylation, acetylation, phosphorylation, etc. Such modifications are well known in the art.

[0146] As used herein, the term "sugar" refers to compounds such as aldoses and ketoses having the stoichiometric formula C(H2O)n (i.e., and therefore "carbohydrates"). The collective term "sugar" includes, but is not limited to, monosaccharides, oligosaccharides, and polysaccharides, as well as substances derived from monosaccharides by reduction of the carbonyl group (alditols), oxidation of one or more terminal groups to carboxylic acids, or replacement of one or more hydroxyl groups by groups such as hydrogen atoms, amino groups, thiol groups, and the like. Derivatives of these compounds are also included.

[0147] For purposes of this application, the term "polynucleotide" (also referred to as "nucleic acid" which may be used interchangeably with the term "polynucleotide") refers to a polymer composed of nucleotide units that may be hydrolyzable, for example, to certain pyrimidine or purine bases (usually adenine, cytosine, guanine, thymine, uracil), d-ribose or 2-deoxy-d-ribose, and phosphate. Non-limiting examples of "polynucleotides" include DNA molecules (e.g., cDNA or genomic DNA), RNA (mRNA), combinations thereof, or hybrid molecules composed of DNA and RNA. Nucleic acids can be double-stranded or single-stranded and can contain both double-stranded and single-stranded fragments. Most preferred are double-stranded DNA molecules and mRNA molecules.

[0148] As used herein, the term "antisense oligonucleotide" refers to a nucleic acid polymer, at least a portion of which is complementary to a nucleic acid present in a normal cell or a diseased cell. Exemplary "antisense oligonucleotides" include antisense RNA, siRNA, and RNAi.

[0149] In this application, the term "CD8(+) T cell-mediated immune response" refers to an immune response mediated by cytotoxic T cells (TCs, also known as cytotoxic T lymphocytes, CTLs, T killer cells, cytolytic T cells, CD8(+) T cells or killer T cells). Examples of cytotoxic T cells include, but are not limited to, antigen-specific effector CD8(+) T cells. For the T cell receptor (TCR) to bind to class I MHC molecules, it must be associated with a glycoprotein called CD8, which binds to the constant portion of class I MHC molecules. These T cells are therefore called CD8(+) T cells. Once activated, TC cells undergo "clonal expansion" with the help of the cytokine interleukin-2 (IL-2), which is a growth and differentiation factor for T cells. This increases the number of cells specific to the target antigen, which can then migrate throughout the body in search of antigen-positive somatic cells.

[0150] As used herein, the term "clonal expansion of antigen-specific CD8(+) T cells" refers to an increase in the number of CD8(+) T cells specific for a target antigen.

[0151] As used herein, the term "cellular immune response" refers to an immune response that does not involve antibodies, but rather involves the activation of phagocytes, antigen-specific cytotoxic T lymphocytes, and the release of various cytokines in response to an antigen.

[0152] As used herein, the term "cytotoxic phenotype of an antigen-specific CD8(+) T cell" refers to a set of observable characteristics of an antigen-specific CD8(+) T cell that are relevant to the cytotoxic function of the cell.

[0153] As used herein, the term "lymph node resident macrophages" refers to macrophages, large white blood cells that are an integral part of our immune system and reside in lymph nodes, small bean-like glands found throughout the body, where they engulf particles and then digest them using a process called phagocytosis.

[0154] As used herein, the term "humoral immune response" refers to immune responses mediated by macromolecules found in extracellular fluids, such as secreted antibodies, complement proteins, and certain antimicrobial peptides. Aspects that involve antibodies are often referred to as antibody-mediated immunity.

[0155] As used herein, the term "B cells", also known as B lymphocytes, are a type of white blood cell of the lymphocyte subtype. They function in the humoral immune component of the adaptive immune system by secreting antibodies.

[0156] As used herein, an "antibody" is a protein comprising one or more polypeptides (including one or more binding domains, preferably antigen-binding domains) substantially or partially encoded by immunoglobulin genes or fragments of immunoglobulin genes. "Immunoglobulin" (Ig) is used interchangeably herein with "antibody". Recognized immunoglobulin genes include the kappa, lambda, alpha, gamma, delta, epsilon and mu constant region genes, as well as a myriad of immunoglobulin variable region genes. In particular, as used herein, an "antibody" is typically a tetrameric, glycosylated protein composed of two light (L) chains, each of approximately 25 kDa, and two heavy (H) chains, each of approximately 50 kDa. Two types of light chains, called lambda and kappa, can be found in antibodies. Depending on the amino acid sequence of the constant domain of the heavy chain, immunoglobulins can be assigned to five major classes, A, D, E, G, and M, some of which can be further divided into subclasses (isotypes), e.g., IgG1, IgG2, IgG3, IgG4, IgA1, and IgA2. IgG is preferred in the context of the present invention. Antibodies related to the present invention are also envisaged that have an IgE constant domain or a part thereof that is bound by the Fc epsilon receptor I. IgM antibodies consist of five basic heterotetramer units and an additional polypeptide called the J chain, and contain ten antigen-binding sites. IgA antibodies, on the other hand, contain two to five basic four-chain units, which can multimerize to form multivalent assemblies in combination with the J chain. In the case of IgG, the four-chain unit is generally about 150,000 daltons. Each light chain comprises an N-terminal variable (V) domain (VL) and a constant (C) domain (CL). Each heavy chain contains an N-terminal V domain (VH), three or four C domains (CH) and a hinge region. The constant domains are not directly involved in binding the antibody to an antigen, but can exhibit various effector functions, such as participating in antibody-dependent cellular cytotoxicity (ADCC).If the antibody is to exert ADCC, it is preferable that the antibody is an IgG1 subtype; IgG4 subtypes will not have the ability to exert ADCC.

[0157] The term "antibody" also includes, but is not limited to, monoclonal, monospecific, polyspecific or multispecific antibodies, such as bispecific antibodies, humanized antibodies, camelized antibodies, human antibodies, single-chain antibodies, chimeric antibodies, synthetic antibodies, recombinant antibodies, hybrid antibodies, mutated antibodies, grafted antibodies, and in vitro generated antibodies, with chimeric or humanized antibodies being preferred. The term "humanized antibody" is generally defined for antibodies in which the CDRs encoding the HC and LC specificities have been transferred into a suitable human variable framework ("CDR grafting"). The term "antibody" also includes scFvs, single-chain antibodies, diabodies or tetrabodies, domain antibodies (dAbs) and nanobodies. In the context of the present invention, the term "antibody" is also intended to include dimeric, trimeric or multimeric forms having several antigen binding sites or bifunctional, trifunctional or multifunctional antibodies.

[0158] Furthermore, the term "antibody" as used in the present invention also relates to derivatives (including fragments) of the antibodies described herein. A "derivative" of an antibody includes an amino acid sequence that has been altered by introducing substitutions, deletions, or additions of amino acid residues. In addition, derivatives also include antibodies that have been modified by covalently binding any type of molecule to the antibody or protein. Examples of such molecules include, but are not limited to, sugars, PEG, hydroxyl groups, ethoxy groups, carboxy groups, or amine groups. In short, covalent modification of antibodies leads to, but is not limited to, glycosylation, PEGylation, acetylation, phosphorylation, amidation, etc.

[0159] The antibodies related to the present invention are preferably "isolated" antibodies. "Isolated", when used to describe the antibodies disclosed herein, means an antibody that has been identified, separated and / or recovered from components of its production environment. Preferably, an isolated antibody is free of association with any other components from its production environment. Contaminating components of the production environment, such as those resulting from recombinant transfected cells, are materials that would typically interfere with diagnostic or therapeutic uses of the polypeptide, and may include enzymes, hormones and other proteinaceous or non-proteinaceous solutes. In a preferred embodiment, the antibody will be (1) purified to a sufficient extent to obtain at least 15 residues of N-terminal or internal amino acid sequence using a spinning cup sequenator, or (2) purified to homogeneity by SDS-PAGE under non-reducing or reducing conditions, using Coomassie blue staining or preferably silver staining. Ordinarily, however, an isolated antibody will be prepared by at least one purification step.

[0160] The term "essentially non-immunogenic" means that the block copolymer or amphiphilic polymer of the present invention does not induce an adaptive immune response, i.e., compared to the encapsulated immunogen, the block copolymer or amphiphilic polymer exhibits less than 30%, preferably less than 20%, more preferably less than 10%, and particularly preferably less than 9, 8, 7, 6 or 5% of the immune response.

[0161] The term "essentially non-antigenic" means that the block copolymer or amphiphilic polymer of the present invention does not specifically bind to a certain group of products of adaptive immunity (e.g. T cell receptors or antibodies), i.e., compared to the encapsulated antigen, the block copolymer or amphiphilic polymer exhibits less than 30%, preferably less than 20%, more preferably less than 10%, and particularly preferably less than 9, 8, 7, 6 or 5% binding.

[0162] Typically, binding affinities are around 10 -6Binding is considered specific when the binding affinity is greater than M. Preferably, the binding affinity is greater than about 10 -11 ~10 -8 M(KD), preferably about 10 -11 ~10 -9 Binding is considered specific when M. If necessary, the binding conditions can be altered to reduce non-specific binding without substantially affecting specific binding.

[0163] The term "amino acid" or "amino acid residue" typically refers to an amino acid having its art-recognized definition, e.g., an amino acid selected from the group consisting of alanine (Ala or A), arginine (Arg or R), asparagine (Asn or N), aspartic acid (Asp or D), cysteine ​​(Cys or C), glutamine (Gln or Q), glutamic acid (Glu or E), glycine (Gly or G), histidine (His or H), isoleucine (He or I), leucine (Leu or L), lysine (Lys or K), methionine (Met or M), phenylalanine (Phe or F), proline (Pro or P), serine (Ser or S), threonine (Thr or T), tryptophan (Trp or W), tyrosine (Tyr or Y), and valine (Val or V), although modified, synthetic, or rare amino acids may be used as desired. In general, amino acids can be classified as having nonpolar side chains (e.g., Ala, Cys, He, Leu, Met, Phe, Pro, Val), negatively charged side chains (e.g., Asp, Glu), positively charged side chains (e.g., Arg, His, Lys), or uncharged polar side chains (e.g., Asn, Cys, Gln, Gly, His, Met, Phe, Ser, Thr, Trp, and Tyr).

[0164] "Effector cells", preferably human effector cells, are leukocytes that express one or more FcRs to perform effector functions. Preferably, these cells express at least FcγRm and perform ADCC effector functions. Examples of human leukocytes that mediate ADCC include peripheral blood mononuclear cells (PBMCs), natural killer (NK) cells, monocytes, cytotoxic T cells and neutrophils. Effector cells can be isolated from native sources, such as blood.

[0165] The term "immunizing" refers to one or more steps of administering to a human, non-human animal one or more antigens such that antibodies can be generated in the animal.

[0166] Specifically, non-human animals are immunized, preferably at least twice, more preferably at least three times, with a polypeptide (antigen) that may be mixed with an adjuvant. An "adjuvant" is a non-specific stimulator of the immune response. An adjuvant may take the form of a composition that includes either or both of the following components: (a) a substance intended to form a deposit that protects the antigen from rapid catabolism (e.g., mineral oil, alum, aluminum hydroxide, liposomes, or surfactants (e.g., pluronic polyols)); and (b) a substance that non-specifically stimulates the immune response of the immunized host animal (e.g., by increasing lymphokine levels therein).

[0167] As used herein, "cancer" refers to a broad group of diseases characterized by the uncontrolled growth of abnormal cells in the body. Unregulated cell division can lead to the formation of malignant tumors or cells that invade adjacent tissues and can metastasize to distant parts of the body via the lymphatic system or bloodstream.

[0168] Non-limiting examples of cancers include squamous cell carcinoma, small cell lung cancer, non-small cell lung cancer, squamous non-small cell lung cancer (NSCLC), non-NSCLC, glioma, gastrointestinal cancer, renal cancer (e.g., clear cell carcinoma), ovarian cancer, liver cancer, colorectal cancer, endometrial cancer, renal cancer (e.g., renal cell carcinoma (RCC)), prostate cancer (e.g., hormone refractory prostate adenocarcinoma), thyroid cancer, neuroblastoma, pancreatic cancer, glioblastoma (glioblastoma multiforme), cervical cancer, gastric cancer, bladder cancer, hepatoma, breast cancer, colon cancer, and head and neck cancer (or cancer), gastric cancer, germ cell tumors. tumors, childhood sarcomas, sinonasal natural killer, melanoma (e.g. metastatic melanoma, e.g. subcutaneous or intraocular melanoma), bone cancer, skin cancer, uterine cancer, anal cancer, testicular cancer, fallopian tube cancer, endometrial cancer, cervical cancer, vaginal cancer, vulvar cancer, esophageal cancer, small intestine cancer, endocrine system cancer, parathyroid cancer, adrenal cancer, soft tissue sarcomas, urethral cancer, penile cancer, childhood solid tumors, ureteral cancer, renal pelvis cancer, central nervous system (CNS) neoplasms, primary CNS lymphoma, tumor angiogenesis, spinal axis tumors, brain stem gliomas, pituitary adenomas, Kaposi's sarcoma, epidermoid carcinoma , squamous cell carcinomas, T-cell lymphomas, environmentally induced cancers, e.g. those induced by asbestos, virus-associated cancers (e.g. human papillomavirus (HPV)-associated tumors), hematological malignancies derived from either of the two major blood cell lineages, i.e. myeloid lineage (producing granulocytes, erythrocytes, platelets, macrophages and mast cells) or lymphoid lineage (producing B cells, T cells, NK cells and plasma cells), e.g. all types of leukemias, lymphomas and myelomas, e.g. acute, chronic, lymphocytic and / or myeloid leukemias, such as acute myeloid leukemia (ALL), acute myeloid leukemia (AML), chronic lymphocytic leukemia (CLL), and chronic myeloid leukemia (CML), anaplastic AML (M0), myeloblastic leukemia (M1), myeloblastic leukemia (M2; with cellular maturation), promyelocytic leukemia (M3 or M3 variant [M3V]), myelomonocytic leukemia (M4 or M4 variant with eosinophilicity [M4E]), monocytic leukemia (M5), erythroleukemia (M6), megakaryoblastic leukemia (M7), isolated granulocytic sarcoma, and chloroma;Lymphomas, e.g. Hodgkin's lymphoma (HL), non-Hodgkin's lymphoma (NHL), B-cell lymphoma, T-cell lymphoma, lymphoplasmacytic lymphoma, monocytoid B-cell lymphoma, mucosa-associated lymphoid tissue (MALT) lymphoma, anaplastic (e.g. Ki1+) large cell lymphoma, adult T-cell lymphoma / leukemia, mantle cell lymphoma, angioimmunoblastic T-cell lymphoma, hemocentric lymphoma, intestinal T-cell lymphoma, primary mediastinal B-cell lymphoma, precursor T-lymphoblastic lymphoma Lymphoma, T-lymphoblastic lymphoma / leukemia (T-Lbly / T-ALL), peripheral T-cell lymphoma, lymphoblastic lymphoma, post-transplant lymphoproliferative disorder, histiocytic lymphoma, primary central nervous system lymphoma, primary effusion lymphoma, lymphoblastic lymphoma (LBL), hematopoietic neoplasms of the lymphatic system, acute lymphoblastic leukemia, diffuse large B-cell lymphoma, Burkitt lymphoma, follicular lymphoma, diffuse histiocytic lymphoma (DHL), immunoblastic large cell lymphoma, precursor B-lymphoblastic lymphoma, cutaneous T-cell lymphoma (CTLC) (also called mycosis fungoides or Sézary syndrome), and lymphoplasmacytic lymphoma (LPL) with Waldenström macroglobulinemia; myelomas, such as IgG myeloma, light chain myeloma, nonsecretory myeloma, smoldering myeloma (also called indolent myeloma), solitary plasmacytoma, and multiple myeloma; chronic lymphocytic leukemia (CLL), hairy cell lymphoma; hematopoietic tumors of the myeloid lineage; fibromyalgia. tumors of mesenchymal origin including sarcoma and rhabdomyosarcoma; seminoma, teratocarcinoma, tumors of the central and peripheral nervous system, e.g. astrocytoma, schwannoma; tumors of mesenchymal origin including fibrosarcoma, rhabdomyosarcoma and osteosarcoma; and other tumors, e.g. melanoma, xeroderma pigmentosum, keratoacanthoma, seminoma, follicular and teratocarcinoma of the thyroid gland, hematopoietic tumors of the lymphatic system, e.g. T-cell tumors and B-cell tumors, T-cell disorders such as, but not limited to, T-prolymphocytic leukemia (T-PLL), including small cell and cerebriform cell types; large granular lymphocyte leukemia (LGL), preferably of the T-cell type; a / d T-NHL hepatosplenic lymphoma; peripheral / post-thymic T-cell lymphoma (pleomorphic and immunoblastic subtypes); angiocentric (nasal) T-cell lymphoma; head and neck cancer, renal cancer, rectal cancer, thyroid cancer;acute myeloid lymphoma, and any combination of the above cancers. The methods described herein can also be used to treat metastatic cancers, refractory cancers (e.g., cancers that are refractory to previous immunotherapy, e.g., with CTLA-4 or PD-1 or PD-L1 blocking antibodies), and recurrent cancers;

[0169] The term "subject" is intended to include living organisms. Examples of subjects include mammals, such as humans, dogs, cows, horses, pigs, sheep, goats, cats, mice, rabbits, rats, and transgenic non-human animals. However, the subject (animal) may also be a non-mammalian animal, such as a bird or a fish. In some preferred embodiments of the present invention, the subject is a human, and in some other preferred embodiments, the subject may be an agricultural animal, which may be either a mammal or a non-mammalian animal. Examples of such non-mammalian animals are birds (e.g., poultry such as chickens, ducks, geese, or turkeys), fish (e.g., farmed fish such as salmon, trout, or tilapia), or crustaceans (such as shrimp or prawns). Examples of mammalian (livestock) animals include goats, sheep, cows, horses, pigs, or donkeys. Other mammals include, for example, cats, dogs, mice, and rabbits. In an exemplary embodiment, the polymersomes of the invention are used for vaccination or immunization of the above-mentioned agricultural animals, both mammalian and non-mammalian agricultural animals (birds, fish, crustaceans), against viral infection (see the Examples). Thus, in such cases, the polymersomes of the invention may encapsulate therein soluble full-length viral proteins or soluble fragments of full-length viral proteins.

[0170] For use in vaccination of both humans and non-human animals, the polymersomes of the present invention or compositions comprising the polymersomes of the present invention may be dissolved in a suitable (pharmaceutical acceptable) buffer, such as phosphate buffered saline (PBS) or 0.9% saline (isotonic solution of 0.90% w / v NaCl with an osmolality of 308 mOsm / L) and administered orally to the respective subject (see again the Examples). The polymersomes may be further mixed with an adjuvant. When administered orally, the adjuvant may help protect the polymersomes from the acidic environment of the stomach. Such adjuvants may be water-miscible or capable of forming water-oil emulsions, such as oil-in-water emulsions or water-in-oil emulsions. Specific examples of such adjuvants are oil-in-water emulsions, water-in-oil emulsions, monophosphoryl lipid A, and / or trehalose dicorynomycolate, where the oil preferably comprises, consists essentially of, or consists of mineral oil, simethicone, Span 80, squalene, and combinations thereof. Further specific examples are monophosphoryl lipid A (e.g., from Salmonella Minnesota), trehalose dicorynomycolate, or mixtures thereof, which may be in the form of an oil-in-water (such as squalene) emulsion. The emulsion may include an emulsifier (e.g., a polysorbate, e.g., polysorbate 80). Alternatively, polymersomes can be modified, such as by coating with natural polymers, or formulated into particles of natural polymers such as alginate or chitosan, or into particles of synthetic polymers such as poly(d,l-lactide-co-glycolide) (PLG), poly(d,l-lactic-co-glycolic acid) (PLGA), poly(g-glutamic acid) (g-PGA) [31,32] or poly(ethylene glycol) (PEG). These particles can be either micrometer-range particles ("macrobeads") or nanoparticles, or nanoparticles incorporated into macrobeads, all of which are well known in the art.See, for example, Hari et al. "Chitosan / calcium-alginate beads for oral delivery of insulin" Applied Polymer Science, Volume 59, Issue 11, 14 March 1996, pp. 1795-1801, Sosnik's review "Alginate Particles as Platform for Drug Delivery by the Oral Route: State-of-the-Art" ISRN Pharmaceutics Volume 2014, Article ID 926157, Machado et al. "Encapsulation of DNA in Macroscopic and Nanosized Calcium Alginate Gel Particles" Langmuir 2013, 29, 15926-15935, International Patent Application WO2015 / 110656, Liang Zhao et al.'s review "Nanoparticle vaccines" Vaccine 32 (2014) 327-337 or Li et al. "Chitosan-Alginate Nanoparticles as a Novel Drug Delivery System" Vaccine 32 (2014) 327-337. See, "Delivery System for Nifedipine" Int J Biomed Sci vol. 4 no. 3 September 2008, 221-228.In exemplary embodiments of these polymersomes and oral formulations, the polymersomes used for vaccination have encapsulated therein viral antigens including influenza hemagglutinin, swine influenza hemagglutinin, foot and mouth disease (FMD) viral proteins such as VP1, VP2 or VP3 coat proteins (VP1 coat protein contains the major antigenic determinant of FMD virions, so that changes in its sequence should be responsible for the high antigenic diversity of this virus), ovalbumin (OVA), spike proteins, such as soluble portions of spike proteins of human pathogenic coronaviruses, such as porcine epidemic diarrhea (PED) virus spike proteins, MERS-CoV spike proteins, SARS-CoV-2 spike proteins, or SARS-CoV-1 spike proteins. As is evident from the use of polymersomes containing soluble portions of influenza hemagglutinin or foot and mouth disease (FMD) viral proteins such as VP1, VP2 or VP3 coat proteins, viral diseases can affect any animal, including birds and mammals, and the mammals can be humans.

[0171] The term "effective amount" or "effective dosage" is defined as an amount sufficient to achieve a desired effect or an amount sufficient to at least partially achieve a desired effect. The term "therapeutically effective amount" is defined as an amount sufficient to cure or at least partially arrest the disease and its complications in a patient already affected by the disease. Amounts effective for this use will depend on the severity of the infection and the general state of the subject's own immune system. The term "patient" includes human and other mammalian subjects receiving either prophylactic or therapeutic treatment.

[0172] The appropriate dosage or therapeutically effective amount of the antibody or antigen-binding portion thereof will depend on the condition being treated, the severity of the condition, previous treatments, and the patient's clinical history and response to the therapeutic agent. The appropriate dose can be adjusted according to the judgment of the attending physician so that it can be administered to the patient once or as a series of doses. The pharmaceutical composition can be administered as the sole therapeutic agent or in combination with additional therapeutic agents as needed.

[0173] If the pharmaceutical composition is lyophilized, the lyophilized material is first reconstituted in a suitable liquid prior to administration, for example, bacteriostatic water for injection (BWFI), saline, phosphate buffered saline (PBS), or the same formulation in which the protein was present prior to lyophilization.

[0174] Pharmaceutical compositions for injection can be presented in unit dosage form, for example in ampoules or in multi-dose containers with added preservatives.In addition, several new drug delivery approaches have been developed, and the pharmaceutical compositions of the present invention are suitable for administration using these new methods, for example, pen-type injectors such as Inject-ease, Genject, Genen, and needleless devices such as MediJector and BioJector.The pharmaceutical compositions can also be adapted to administration methods that have not yet been discovered.See also Langer, 1990, Science, 249:1527-1533.

[0175] The pharmaceutical composition may be prepared for intranasal or inhalation administration, for example for local administration to the airways and / or lungs. Means and devices for inhalation administration of substances are known to those skilled in the art and are disclosed, for example, in WO94 / 017784A and Elphick et al. (2015) Expert Opin Drug Deliv, 12, 1375-87. Such means and devices include nebulizers, metered dose inhalers, powder inhalers, and nasal sprays. Other suitable means and devices for inhalation administration of drugs or vaccines are known in the art. The preferred route of local administration to the airways and / or lungs is by aerosol inhalation. Pulmonary drug delivery, i.e. by inhalation of aerosols (which can also be used for intranasal administration) or by intratracheal instillation, is reviewed, for example, in Patton, JS, et al. (2004) Proc. Amer. Thoracic Soc., 1, 338-344. Nebulizers are useful for generating aerosols from solutions, while metered dose inhalers, dry powder inhalers, etc. are effective for generating small particle aerosols. Thus, the pharmaceutical composition may be formulated in the form of an aerosol (mixture), spray, mist or powder.

[0176] Pharmaceutical compositions against mucosal pathogens, such as respiratory coronaviruses, such as SARS-CoV-2, MERS, or SARS-CoV1, should confer long-lasting protective immunity at both the systemic and mucosal levels. Thus, the pharmaceutical compositions of the present disclosure may be preferably prepared for mucosal administration, such as inhalation or intranasal administration. As shown in Example 14, intranasal administration of a coronavirus vaccine can induce not only a mucosal immune response, but also a systemic immune response. The pharmaceutical compositions of the present disclosure may also be preferably prepared for systemic administration, such as intramuscular administration.

[0177] A nebulizer is a drug delivery device used to administer medication in the form of a mist that is inhaled into the lungs. Various types of nebulizers are known to those skilled in the art, including jet nebulizers, ultrasonic nebulizers, vibrating mesh technology, soft mist inhalers, and the like. Some nebulizers provide a continuous flow of nebulized solution; that is, they will result in continuous nebulization over an extended period of time, whether or not the subject inhales it. On the other hand, other nebulizers are breath-actuated; that is, the subject will only get any dosage if he or she inhales from them. The vaccines of the present invention, particularly vaccines for human pathogenic coronavirus infections such as MERS, COVID-19, or SARS, can be formulated for use in a nebulizer and can be contained in or administered using a nebulizer.

[0178] A metered dose inhaler (MDI) is a device that delivers a specific amount of medication to the lungs in the form of a short burst of liquid aerosolized medicine. Such metered dose inhalers generally consist of three main components: a canister containing the formulation to be administered, a metering valve that allows a metered amount of the formulation to be dispensed per actuation, and an actuator (or mouthpiece) that allows the patient to operate the device and direct the liquid aerosol to the lungs. The vaccines of the present invention, particularly vaccines for human pathogenic coronavirus infections such as MERS, COVID-19, or SARS, can be formulated for use in MDIs and can be contained in or administered using MDIs, particularly canisters for MDIs.

[0179] A dry powder inhaler (DPI) is a device that delivers a drug to the lungs in the form of a dry powder. Dry powder inhalers are an alternative to aerosol-based inhalers, such as metered dose inhalers. The drug is generally held in a capsule for manual loading or in a dedicated blister package placed inside the inhaler. The vaccine of the present invention, particularly a vaccine for a human pathogenic coronavirus infection such as MERS, COVID-19, or SARS, can be formulated for use in a DPI and can be contained in or administered using a DPI, particularly a capsule or blister package for an MDI.

[0180] A nasal spray can be used for nasal administration, where a drug is inhaled through the nose. The vaccines of the present invention, particularly vaccines for human pathogenic coronavirus infections such as MERS, COVID-19, or SARS, can be formulated as nasal sprays and contained in nasal spray bottles or administered as nasal sprays.

[0181] Pharmaceutical compositions can also be formulated as depot preparations.Such long-acting formulations can be administered by implantation (e.g. subcutaneous, intraligamentous or intratendinous, subsynovial or intramuscular), subsynovial injection or intramuscular injection.Thus, for example, the formulation can be modified with suitable polymeric or hydrophobic materials (e.g. as emulsion in acceptable oil) or ion exchange resin, or modified as sparingly soluble derivatives, for example as sparingly soluble salts.

[0182] The pharmaceutical compositions may be in a variety of conventional depot forms used for administration to provide the reactive composition, including, for example, solid, semi-solid and liquid dosage forms such as solutions or suspensions, slurries, gels, creams, balms, emulsions, lotions, powders, sprays, foams, pastes, ointments, salves, balms and drops.

[0183] If desired, pharmaceutical composition can be presented in a vial, pack or dispenser device, which can contain one or more unit dosage forms containing active ingredient.In one embodiment, dispenser device can contain a syringe with a single dose of liquid formulation ready for injection.Syringe can be accompanied by instructions on administration.

[0184] Pharmaceutical compositions may further comprise additional pharmaceutically acceptable components. The proteins described herein may also comprise other pharmaceutically acceptable carriers, excipients, or stabilizers, such as those described in Remington's Pharmaceutical Sciences 16th edition, Osol, A. Ed. (1980), as long as they do not adversely affect the desired characteristics of the formulation. As used herein, "pharmaceutically acceptable carriers" refers to any and all solvents, dispersion media, coatings, antibacterial and antifungal agents, isotonic and absorption delaying agents that are compatible with pharmaceutical administration. The use of such media and agents for pharmaceutically active substances is well known in the art. Acceptable carriers, excipients or stabilizers are nontoxic to recipients at the dosages and concentrations employed and may include additional buffering agents; preservatives; co-solvents; antioxidants, such as ascorbic acid and methionine; chelating agents, such as EDTA; metal complexes (e.g., Zn-protein complexes); biodegradable polymers, such as polyesters; salt-forming counterions, such as sodium, polyhydric sugar alcohols; amino acids, such as alanine, glycine, asparagine, 2-phenylalanine, and threonine; sugars or sugar alcohols, such as lactitol, stachyose, mannose, sorbose, xylose, These include ribose, ribitol, myoinisitose, myoinisitol, galactose, galactitol, glycerol, cyclitols (e.g., inositol), polyethylene glycol; sulfur-containing reducing agents, such as glutathione, thioctic acid, sodium thioglycolate, thioglycerol, [alpha]-monothioglycerol, and sodium thiosulfate; low molecular weight proteins, such as human serum albumin, bovine serum albumin, gelatin, or other immunoglobulins; and hydrophilic polymers, such as polyvinylpyrrolidone.

[0185] The formulations described herein are useful as pharmaceutical compositions in the treatment and / or prevention of the pathological medical conditions described herein in patients in need thereof. The term "treatment" refers to both therapeutic treatment and prophylactic or preventative measures. Treatment includes application or administration of the formulation to the body, isolated tissue or cells of a patient having a disease / disorder, a symptom of a disease / disorder, or a predisposition to a disease / disorder, with the purpose of curing, healing, alleviating, relieving, altering, correcting, improving, ameliorating, or affecting the disease, the symptom of a disease, or the predisposition to a disease.

[0186] As used herein, the terms "treat" and "treatment" refer to administering a therapeutically effective amount of a pharmaceutical composition of the present invention to a subject. A "therapeutically effective amount" refers to an amount of a pharmaceutical composition or antibody sufficient to treat or ameliorate a disease or disorder, delay the onset of a disease, or provide some therapeutic benefit in the treatment or management of a disease.

[0187] As used herein, the term "prevention" refers to the use of an agent to prevent the onset of a disease or disorder. A "prophylactically effective amount" defines the amount of an active component or pharmaceutical agent sufficient to prevent the onset or recurrence of a disease.

[0188] As used herein, the terms "disorder" and "disease" are used interchangeably to refer to a condition in a subject. In particular, the term "cancer" is used interchangeably with the term "tumor."

[0189] Kits of the present invention will typically include the containers described above, as well as one or more other containers containing materials desirable from a commercial and user standpoint, such as buffers, diluents, filters, needles, syringes, and package inserts with instructions for use.

[0190] For purposes of this application, the term "liposome" refers to a spherical vesicle having at least one lipid bilayer.

[0191] For purposes of this application, the term "endosome" refers to a membrane-bound compartment (i.e., a vacuole) within a eukaryotic cell into which material taken up by endocytosis is delivered.

[0192] For the purposes of this application, the term "late endosome" refers to a pre-lysosomal endocytic organelle that is distinct from early endosomes by its lower luminal pH and different protein composition. Late endosomes are more spherical than early endosomes, are mostly located near the nucleus, and are concentrated near the microtubule-organizing center.

[0193] For the purposes of this application, the term "T helper cells" (also called TH cells or "effector CD4(+) T cells") refers to T lymphocytes that assist other white blood cells in immunological processes, including B cell maturation into plasma cells and memory B cells, and activation of cytotoxic T cells and macrophages. These cells are also known as "CD4(+) T cells" because they express the CD4 glycoprotein on their surface. Helper T cells are activated when presented with, for example, peptide antigens, by MHC class II molecules expressed on the surface of antigen-presenting cells (APCs).

[0194] As used herein, the term "autoantigen" refers to any molecule or chemical group in one organism that acts as an antigen in inducing antibody formation in another organism, but to which the healthy immune system of the parent organism is tolerant.

[0195] The term "% identity" used herein refers to the percentage of identical amino acid residues at corresponding positions in sequences when comparing two amino acid sequences in optimal sequence alignment, as exemplified by the ClustalW method or ClustalX method available at www.clustal.org or equivalent techniques.Thus, align both sequences (reference sequence and sequence of interest), identify the identical amino acid residues between both sequences, and divide the total number of identical amino acids by the total number of amino acids (amino acid length).The result of this division is a percentage value, i.e., percentage identity value / percent identity.

[0196] Since the immunization method of the present invention can be carried out by using a full-length soluble encapsulated antigen (e.g., a protein) or a fragment of said protein in a synthetic environment that allows its proper folding, the probability of isolating an antibody capable of detecting the corresponding antigen (e.g., a membrane protein) in vivo will be high. Moreover, the immunization and antibody generation can be carried out without any prior knowledge of the membrane protein structure, which would otherwise be required when using a peptide-based immunization approach.

[0197] Furthermore, in comparison to other techniques, the methods of the present invention allow for the rapid and cost-effective production of membrane proteins encapsulated in an oxidatively stable membrane environment.

[0198] In some aspects, the present invention relates to a method for eliciting an immune response against an antigen (e.g., an immunogen) in a subject. The method may comprise administering to a subject a composition comprising a polymersome of the present invention having a membrane (e.g., a surrounding membrane) of an amphiphilic polymer. The composition further comprises a soluble antigen encapsulated by the membrane of the amphiphilic polymer of the polymersome of the present invention. The immunogen may be a membrane-bound protein. In some further aspects, the polymersome of the present invention comprises a lipid polymer. Administration may be performed in any suitable manner, for example, orally, topically, topically to the airways, topically to the lungs, by inhalation, intranasally, or by injection.

[0199] One of skill in the art can determine and adjust the frequency of administration (e.g., oral administration or injection) depending on the level of response desired. For example, a control (which may include a mammal) can be given a weekly or biweekly administration (e.g., oral administration or injection) of a polymersome of the invention. The immune response can be measured by quantifying the blood concentration level (titer) of antibodies in the mammal to an initial amount of antigen encapsulated in a polymersome of the invention (see "Examples").

[0200] Polymersome structures can include amphiphilic block copolymers that self-assemble into vesicles to encapsulate various antigens (e.g., soluble proteins) using solvent re-hydration methods, direct dispersion, or spontaneous self-assembly (e.g., Example 1 described herein).

[0201] In the context of this application, the term "soluble antigen" as used herein means an antigen that can be dissolved or liquefied. As a specific example, a soluble antigen may consist of amino acids from the extracellular and / or intracellular regions of a membrane protein. However, a soluble antigen may also comprise amino acids from the extracellular and / or intracellular regions of a membrane protein and one or more additional amino acids belonging to the transmembrane region of a membrane protein, as long as the antigen can still be dissolved or liquefied. As a specific example, a soluble fragment of the MERS-CoV spike protein of SEQ ID NO:43, which contains one amino acid (position 1297) belonging to the transmembrane region, is a soluble antigen in the sense of the present disclosure. However, it is envisaged that a soluble antigen preferably lacks at least a portion of the transmembrane region or the entire transmembrane region. The term "soluble antigen" encompasses "solubilized" antigens, i.e. antigens that have been rendered soluble by the action of detergents or other agents or that have increased solubility, especially in water. Exemplary, non-limiting, soluble antigens of the present invention include polypeptides derived from insoluble portions of proteins, hydrophobic polypeptides that have been made soluble for inclusion, and aggregated polypeptides that are soluble as aggregates.

[0202] In some aspects, the antigens (e.g., membrane proteins) of the present invention are solubilized using detergents, surfactants, temperature changes, or pH changes. The vesicle structure provided by the amphiphilic block copolymer allows the antigens (e.g., membrane proteins) to fold in a physiologically correct and functional manner, thereby allowing the immune system of the target mammal to detect the antigen and thereby generate a strong immune response.

[0203] In some aspects, injection of the compositions of the invention can include intraperitoneal injection, subcutaneous or intravenous injection, intramuscular injection, or non-invasive administration. In other aspects, injection of the compositions of the invention can include intradermal injection.

[0204] In some other aspects, the immune response level can be further enhanced or boosted by including an adjuvant in the composition comprising the polymersomes of the present invention. The adjuvant can be an encapsulated adjuvant or a non-encapsulated adjuvant. The adjuvant can be mixed with the polymersomes of the present invention or the combination of the present invention. The adjuvant can be soluble in water or in the form of a water-oil emulsion. In such aspects, the polymersomes and the adjuvant can be administered to the subject simultaneously.

[0205] In some aspects, the block copolymers or amphiphilic polymers of the polymersomes of the invention are not immunostimulants or adjuvants.

[0206] In some other aspects, the block copolymers or amphiphilic polymers of the present invention are immunostimulants and / or adjuvants.

[0207] In some further aspects, the polymersomes of the invention are immunogenic.

[0208] In some further aspects, the polymersomes of the invention are non-immunogenic.

[0209] In some aspects, the adjuvant may be administered separately from the administration of the composition of the invention comprising the polymersome of the invention. The adjuvant may be administered before, simultaneously with, or after the administration of the composition comprising the polymersome encapsulating the antigen of the invention. For example, the adjuvant may be injected into a subject after the injection of the composition comprising the polymersome encapsulating the antigen of the invention. In some aspects, the adjuvant may be encapsulated in a polymersome together with the antigen. In other preferred aspects, the adjuvant is encapsulated in a separate polymersome. That is, the adjuvant is encapsulated separately from the antigen, so that the antigen is encapsulated in a first type of polymersome and the adjuvant is encapsulated in a second type of polymersome. It should be noted here that the adjuvant and the polymersome may be encapsulated in a polymersome formed from the same amphiphilic polymer. Each antigen and CpG oligodeoxynucleotide as an exemplary adjuvant See Examples 7-9 or Example 14 or Example 18 of the present application, where TIFF0007676030000004.tif11150 are both encapsulated in BD21 polymersomes. Alternatively, the amphiphilic polymer used to encapsulate the antigen may be different from the amphiphilic polymer used to encapsulate the adjuvant. As a purely illustrative example, the antigen is encapsulated in BD21 polymersomes while the adjuvant is encapsulated in PDMS 12 -PEO 46 Polymersomes or PDMS 47 PEO 36 It may be encapsulated in a polymersome.

[0210] Any known adjuvant can be used in the present invention, and those skilled in the art will readily recognize and understand that the type of adjuvant injected may depend on the type of antigen used to elicit an immune response. The adjuvant may be an antigen of bacterial, viral, or fungal origin. The adjuvant may be a nucleic acid, such as CpG oligodeoxynucleotides (also known as "CpG ODN" or referred to herein as "CpG"). CpG molecules are naturally occurring oligonucleotides of bacterial origin that contain unmethylated CpG dinucleotides in specific sequence contexts (CpG motifs). These CpG motifs occur 20 times more frequently in bacterial DNA compared to mammalian DNA. CpG ODNs are recognized by Toll-like receptor 9 (TLR9) to provide strong immune stimulatory effects and are widely available commercially. Specific examples of commercially available CpG ODNs include those with the sequence ODN2006 (SEQ ID NO:62, commercially available from Miltenyi Biotech as catalog number 130-100-106), a 24-mer having the sequence TIFF0007676030000005.tif4128; ODN2007, a 22-mer with sequence TIFF0007676030000006.tif4128 TIFF0007676030000007.tif4128, a 20-mer having the sequence ODN1826 listed above, or and ODN2216, a 20-mer with TIFF0007676030000008.tif4128, all three of which are commercially available from InvivoGen. As natural DNA molecules, the bases are linked together by phosphodiester bonds (PO4). However, this bond is susceptible to degradation by nucleases. When used as an adjuvant without any protective element, natural CpG molecules have a very short half-life in the body. To avoid this short half-life, the phosphodiester bond can be replaced by a phosphorothioate bond by changing one of the oxygen atoms to a sulfur atom. This substitution prevents degradation by nucleases and increases the half-life of the modified CpG. For example, the CpG molecules ODN2006, ODN2007 or ODN1826 are provided in a fully phosphorothioate backbone form to make them nuclease-resistant. Alternatively, CpG is encapsulated in cationic liposomes to avoid degradation by nucleases. In addition to CpG, many other widely used Toll-like receptor agonists, such as polyinosinic:polycytidylic acid (poly(I:C)) (TLR3), lipopolysaccharide (LPS) (TLR4), monophosphoryl lipid (MPL) (TLR5), can be used as one or more adjuvants in the present invention. Furthermore, components from bacterial or mycobacterial cell walls, such as those present in the Sigma Adjuvant System or in Freund's adjuvant, or proteins such as keyhole limpet hemocyanin (KLH), are further examples of adjuvants that can be used in the present invention as well. Further examples of suitable adjuvants that can be used in the present invention include the Sigma Adjuvant System (SAS) or simethicone or alpha-tocopherol. Other antigen-adjuvant pairs are also suitable for use in the method of the present invention.

[0211] In this context, the term "adjuvant" as used herein is not limited to pharmacological or immunological agents that modify the effect of other agents (as the adjuvants described above are), but means "any substance that stimulates the action of the immune system". Thus, checkpoint inhibitors that stimulate the action of the immune system are also encompassed by the term adjuvant as used herein. For example, PD-L1 present on the cell surface binds to PD1 on the surface of immune cells, inhibiting immune cell activity. Thus, for example, an antibody that binds to either PD-1 or PD-L1 and blocks the interaction between PD1 and PD-L1 is a "positive checkpoint inhibitor" because it can enable T cells to attack tumors.

[0212] In some aspects, the membrane protein used as antigen in the present invention may comprise a fragment or extracellular domain of a transmembrane protein. The antigen may also be a (full-length) transmembrane protein, a G protein-coupled receptor, a neurotransmitter receptor, a kinase, a porin, an ABC transporter, an ion transporter, an acetylcholine receptor and a cell adhesion receptor. The membrane protein may be fused or coupled to a tag or may not contain a tag. When the membrane protein is tagged, the tag may be selected from well-known affinity tags such as VSV, His-tag, Strep-tag®, Flag-tag, intein-tag or GST-tag, or a partner of an anti-affinity binding pair such as biotin or avidin, or a label such as a fluorescent label, an enzyme label, an NMR label or an isotopic label.

[0213] In some aspects, the membrane protein or a fragment (or portion) thereof may be provided prior to encapsulation or may be encapsulated simultaneously with production of the protein by a cell-free expression system, which may be an in vitro transcription-translation system.

[0214] The cell-free expression system can also be a eukaryotic cell-free expression system, such as the TNT system based on rabbit reticulocytes, wheat germ extracts or insect extracts, a prokaryotic cell-free expression system or an archaeal cell-free expression system.

[0215] The antigens or fragments (or portions) of the present disclosure may be produced in vivo. The antigens or fragments (or portions) may be produced, for example, in a bacterial or eukaryotic host organism and isolated from the host organism or a culture thereof. The antigens or fragments (or portions) may also be produced in vitro, for example, by using an in vitro translation system. A preferred expression system is the baculovirus expression system. The use of baculovirus protein expression systems is often overlooked because it is viewed as slow and expensive. However, one of the great advantages of the baculovirus system is that cell lines can be generated and maintained independent of the virus. This allows for the rapid production of new subunit antigens without the need to obtain regulatory approval for new cell lines, a useful tool given the rapid sequence changes of viruses such as MERS-CoV and SARS-CoV-1. Moreover, the baculovirus system produces antigens with novel glycosylation profiles compared to mammalian systems, which have been shown to enhance immune responses. For example, for SARS-CoV-1 and MERS-CoV, the entire soluble (S1-S2) domain of the spike protein can be expressed in Sf9 cells. When immunized in Balb / c mice, these proteins, whether administered alone or with alum or Matrix M1 adjuvants, show high virus neutralization titers that can persist for at least 45 days. Thus, the antigens of the present disclosure are preferably produced using eukaryotic host cells, preferably insect cells, such as Sf9 cells, or preferably using a baculovirus expression system.

[0216] As described above, the polymersomes can be formed from amphiphilic diblock or triblock copolymers. In various aspects, the amphiphilic polymer can include at least one carboxylic acid, amide, amine, alkylene, dialkylsiloxane, ether, or alkylene sulfide monomer unit.

[0217] In some aspects, the amphiphilic polymer can be a polyether block selected from the group consisting of an oligo(oxyethylene) block, a poly(oxyethylene) block, an oligo(oxypropylene) block, a poly(oxypropylene) block, an oligo(oxybutylene) block, and a poly(oxybutylene) block. Further examples of blocks that may be included in the polymer include, but are not limited to, poly(acrylic acid), poly(methyl acrylate), polystyrene, poly(butadiene), poly(2-methyloxazoline), poly(dimethylsiloxane), poly(e-caprolactone), poly(propylene sulfide), poly(N-isopropylacrylamide), poly(2-vinylpyridine), poly(2-(diethylamino)ethyl methacrylate), poly(2-diisopropylamino)ethyl methacrylate), poly(2-methacryloyloxy)ethyl phosphorylcholine, poly(isoprene), poly(isobutylene), poly(ethylene-co-butylene), and poly(lactic acid). Examples of suitable amphiphilic polymers include poly(ethylethylene)-b-poly(ethylene oxide) (PEE-b-PEO), poly(butadiene)-b-poly(ethylene oxide) (PBD-b-PEO), poly(styrene)-b-poly(acrylic acid) (PS-PAA), poly(dimethylsiloxane)-poly(ethylene oxide), also known as poly(dimethylsiloxane-b-ethylene oxide) (referred to herein as PDMS-PEO), poly(dimethylsiloxane)-poly(acrylic acid) (PDMS-PAA), e.g., PMOXA as used by May et al., 2013. 20 -PDMS 54 -PMOXA 20Examples of block copolymers include, but are not limited to, poly(2-methyloxazoline)-b-poly(dimethylsiloxane)-b-poly(2-methyloxazoline) (PMOXA-bPDMS-bPMOXA), poly(2-methyloxazoline)-b-poly(dimethylsiloxane)-b-poly(ethylene oxide) (PMOXA-b-PDMS-b-PEO), poly(ethylene oxide)-b-poly(propylene sulfide)-b-poly(ethylene oxide) (PEO-b-PPS-b-PEO), and poly(ethylene oxide)-poly(butylene oxide) block copolymers, including triblock copolymers such as (ABA). Block copolymers can be further specified by the average block length of each block contained in the copolymer. Thus, PB M PEO N indicates the presence of a polybutadiene block (PB) of length M and a polyethylene oxide (PEO) block of length N. M and N are independently selected integers, which may be selected, for example, within the range of about 6 to about 60. Thus, PB 35 PEO 18 indicates the presence of polybutadiene blocks of average length 35 and polyethylene oxide blocks of average length 18. In certain aspects, the PB-PEO diblock copolymer comprises 5-50 blocks PB and 5-50 blocks PEO. Similarly, PB 10 PEO 24 indicates the presence of polybutadiene blocks of average length 10 and polyethylene oxide blocks of average length 24. Specific examples of suitable PB-PEO diblock copolymers that can be used in the present invention include the diblock copolymer PBD 21 -PEO 14 (also commercially available) and [PBD] 21 -[PEO] 12 (See WO2014 / 077781A1 and Nallani et al., 2011). As a further example, E O B Pindicates the presence of an ethylene oxide block (E) of length O and a butadiene block (B) of length P. Thus, O and P are independently selected integers, ranging, for example, from about 10 to about 120. Thus, E 16 E 22 indicates the presence of ethylene oxide blocks of average length 16 and butadiene blocks of average length 22.

[0218] Turning now to another preferred block copolymer used to form the polymersomes of the present invention, poly(dimethylsiloxane-b-ethylene oxide) (PDMS-PEO), it is noted that both linear and comb-shaped PDMS-PEO can be used here (see Gaspard et al. "Mechanical Characterization of Hybrid Vesicles Based on Linear Poly(Dimethylsiloxane-b-Ethylene Oxide)and Poly(Butadiene-b-Ethylene Oxide)Block Copolymers," Sensors 2016,16(3),390, which describes polymersomes formed from PDMS-PEO).

[0219] The structure of linear PDMS-PEO is shown below as formula (I): The structure of the comb-type PDMS-PEO is shown as formula (II): Shown as TIFF0007676030000010.tif42128. PDMS according to structural formula (I) n -PEO m The term "polydimethylsiloxane" refers to the presence of a polydimethylsiloxane (PDMS) block of length n and a polyethylene oxide (PEO) block of length m, where m and n are independently selected integers and can each be selected in the ranges, for example, from about 5 or about 6 to about 100, from about 5 to about 60, or from about 6 to about 60, or from about 5 to about 50. For example, PDMS 12 -PEO 46 or PDMS 47 PEO36 Linear PDMS-PEO such as PDMS-PEO-1, PDMS-PEO-2, PDMS-PEO-3, PDMS-PEO-4, PDMS-PEO-5, PDMS-PEO-6, PDMS-PEO-7, PDMS-PEO-8, PDMS-PEO-9, PDMS-PEO-10, PDMS-PEO-20, PDMS-PEO-30, PDMS-PEO-40, PDMS-PEO-50, PDMS-PEO-60, PDMS-PEO-70, PDMS-PEO-80, PDMS-PEO-90, PDMS-PEO-10, PDMS-PEO-11, PDMS-PEO-12, PDMS-PEO-13, PDMS-PEO-14, PDMS-PEO-15, PDMS-PEO-16, PDMS-PEO-17, PDMS-PEO-18, PDMS-PEO-19, PDMS-PEO-20, PDMS-PEO-21, PDMS-PEO-22, PDMS-PEO-23, PDMS-PEO-24, PDMS-PEO-25, PDMS-PEO-26, PDMS-PEO-27, PDMS-PEO-28, PDMS-PEO-29 ...9, PDMS-PEO-29, PDMS-PEO-29, PDMS-PEO-24,

[0220] In accordance with the above, the present invention relates in one aspect to a method for inducing an immune response in a subject, comprising administering to the subject a polymersome formed from PDMS-PEO carrying an antigen. The antigen can be associated / physically linked to the PDMS-PEO polymersome in any suitable manner. For example, the PDMS-PEO polymersome can have a soluble antigen encapsulated therein, as described in the present invention. Alternatively or additionally, the polymersome can have an antigen incorporated / incorporated into the surrounding membrane of the polymersome, as described in WO2014 / 077781A1. In this case, the antigen is a membrane protein whose transmembrane domain(s) is incorporated into the surrounding membrane of the PDMS-PEO-polymersome. Incorporation can be achieved as described in WO2014 / 077781A1 or Nallani et al. "Proteopolymersomes: in vitro production of a membrane protein in polymersome membranes", Biointerphases, 1 December 2011, page 153. When an antigen is encapsulated in a PDMS-PEO polymersome, it may be a soluble antigen selected from the group consisting of polypeptides, carbohydrates, polynucleotides, and combinations thereof. The present invention further relates to a method for producing such encapsulated antigens in PDMS-PEO polymersomes and the polymersomes produced by said method.

[0221] The present invention further relates to compositions comprising PDMS-PEO polymersomes carrying an antigen. Again, in these compositions, the antigen can be associated / physically linked to the PDMS-PEO polymersome in any suitable manner. For example, the PDMS-PEO polymersomes can have a soluble antigen encapsulated therein, as described in the present invention. Alternatively or additionally, the polymersomes can have an antigen incorporated / incorporated into the membrane surrounding the polymersome, as described in WO2014 / 077781A1. The present invention also relates to a vaccine comprising such PDMS-PEO polymersomes carrying an antigen, a method of eliciting an immune response, or a method for treating, ameliorating, preventing or diagnosing cancer, an autoimmune disease or an infectious disease, comprising the step of administering to a subject in need thereof a PDMS-PEO polymersome carrying an antigen.

[0222] In accordance with the above, the present invention also relates to the in vitro and in vivo use of PDMS-PEO polymersomes carrying (or carrying) antigens in a form suitable for eliciting an immune response. The antigens can be encapsulated in the PDMS-PEO polymersomes or incorporated in the surrounding membrane of the polymersomes, for example as described in WO2014 / 077781A1.

[0223] Another preferred block copolymer is poly(dimethylsiloxane)-poly(acrylic acid) (PDMS-PAA), which denotes the presence of a poly(dimethylsiloxane) (PDMS) block of length M and a poly(acrylic acid) (PAA) block of length N. M -PAA NM and N are independently selected integers, e.g., selected from the range of about 5 to about 100, representing the average length of the blocks. The PDMS-PAA preferably comprises 5 to 100 blocks of PDMS and 5 to 100 blocks of PAA. The PDMS-PAA preferably comprises 5 to 50, preferably 10 to 40 blocks of PDMS and / or 5 to 30, preferably 5 to 25, preferably 5 to 20 blocks of PAA. The PDMS-PAA preferably comprises PDMS 30 -PAA 14 , PDMS 15 -PAA7 or PDMS 34 -PAA 16 is selected from the group consisting of:

[0224] In certain aspects, the polymersomes of the present invention may contain one or more compartments (also referred to as "multicompartments"). The compartmentalization of the vesicular structure of polymersomes allows the coexistence of complex reaction pathways in living cells and helps to separate many activities in the cell spatially and temporally. Thus, two or more types of antigens may be encapsulated in the polymersomes of the present invention. The different antigens may have the same or different isoforms. Each compartment may be formed of the same or different amphiphilic polymers. In various aspects, two or more different antigens are incorporated into the surrounding membrane of the amphiphilic polymer. Each compartment may encapsulate at least one of a peptide, a protein, and a nucleic acid. The peptide, protein, polynucleotide, or carbohydrate may be immunogenic.

[0225] Further details of suitable multi-compartmental polymersomes can be found in WO20121018306, the contents of which are incorporated herein by reference in their entirety for all purposes.

[0226] Additionally, polymersomes may be free-standing or immobilized on a surface, for example as described in WO2010 / 1123462, the contents of which are incorporated herein by reference in their entirety for all purposes.

[0227] When the polymersome carrier contains two or more compartments, the compartments may include an outer block copolymer vesicle and at least one inner block copolymer vesicle encapsulated inside the outer block copolymer vesicle. In some aspects, each of the block copolymers of the outer vesicle and the inner vesicle includes a polyether block, such as a poly(oxyethylene) block, a poly(oxypropylene) block, and a poly(oxybutylene) block. Further examples of blocks that may be included in the copolymer include, but are not limited to, poly(acrylic acid), poly(methyl acrylate), polystyrene, poly(butadiene), poly(2-methyloxazoline), poly(dimethylsiloxane), poly(L-isocyanoalanine(2-thiophen-3-yl-ethyl)amide), poly(e-caprolactone), poly(propylene sulfide), poly(N-isopropylacrylamide), poly(2-vinylpyridine), poly(2-(diethylamino)ethyl methacrylate), poly(2-(diisopropylamino)ethyl methacrylate), poly(2-(methacryloyloxy)ethyl phosphorylcholine), and poly(lactic acid).Examples of suitable outer and inner vesicles include poly(ethylethylene)-b-poly(ethylene oxide) (PEE-b-PEO), poly(butadiene)-b-poly(ethylene oxide) (PBD-b-PEO), poly(styrene)-b-poly(acrylic acid) (PS-b-PAA), poly(ethylene oxide)-poly(caprolactone) (PEO-b-PCL), poly(ethylene oxide)-poly(lactic acid) (PEO-b-PLA ), poly(isoprene)-poly(ethylene oxide) (PI-b-PEO), poly(2-vinylpyridine)-poly(ethylene oxide) (P2VP-b-PEO), poly(ethylene oxide)-poly(N-isopropylacrylamide) (PEO-b-PNIPAm), poly(ethylene glycol)-poly(propylene sulfide) (PEG-b-PPS), poly(dimethylsiloxane)-poly(acrylic acid) (PDMS-PAA), Poly(methylphenylsilane)-poly(ethylene oxide) (PMPS-b-PEO-b-PMPS-b-PEO-b-PMPS), poly(2-methyloxazoline)-b-poly-(dimethylsiloxane)-b-poly(2-methyloxazoline) (PMOXA-b-PDMS-b-PMOXA), poly(2-methyloxazoline)-b-poly(dimethylsiloxane)-b-poly(ethylene oxide) (PMOXA-b-PDMS-b- Examples of block copolymers include, but are not limited to, poly(styrene-b-poly(L-isocyanoalanine(2-thiophen-3-yl-ethyl)amide)] (PS-b-PIAT), poly(ethylene oxide)-b-poly(propylene sulfide)-b-poly(ethylene oxide) (PEO-b-PPS-b-PEO) and poly(ethylene oxide)-poly(butylene oxide) (PEO-b-PBO) block copolymers. Block copolymers can be further specified by the average number of each block contained in the copolymer. Thus, PS. M -PIAT Nindicates the presence of a polystyrene block (PS) having M repeat units and a poly(L-isocyanoalanine(2-thiophen-3-yl-ethyl)amide) (PIAT) block having N repeat units. M and N are thus independently selected integers, which may be selected, for example, within the range of about 5 to about 95. Thus, PS 40 -PIAT 50 indicates the presence of PS blocks with an average of 40 repeat units and PIAT blocks with an average of 50 repeat units.

[0228] In some aspects, the polymersomes of the present disclosure contain lipids, which are preferably mixed with the block copolymer or amphiphilic polymer. The content of lipids is typically low compared to the amount of block copolymer or amphiphilic polymer. Typically, lipids will be up to about 50%, up to about 45%, up to about 40%, up to about 35%, up to about 30%, up to about 20%, up to about 15%, up to about 10%, up to about 5%, up to about 2%, up to about 1%, up to 0.5%, up to about 0.2%, up to about 0.1% of the components forming the polymersome membrane (percentages given by weight). The addition of lipids may improve the encapsulation efficiency. The lipids may be synthetic lipids, natural lipids, lipid mixtures, or combinations of synthetic and natural lipids. Non-limiting examples of lipids are lipid mixtures containing phospholipids, such as phosphatidylcholine, e.g., POPC, lecithin, cephalin, or phosphatidylinositol, or phospholipids, such as soybean phospholipids, e.g., asolectin. Further non-limiting examples of lipids include cholesterol, cholesterol sulfate, 1,2-dioleoyl-3-trimethylammonium propane (DOTAP). Lipids are preferably non-antigenic. In some aspects, the polymersomes of the present disclosure contain less than about 20%, less than about 15%, less than about 10%, less than about 5%, less than about 2%, less than about 1%, less than about 0.5%, less than about 0.2%, less than about 0.1% saponin, or are essentially free of saponin (percentages given by weight).

[0229] In some aspects, the present invention relates to a method for producing an encapsulated antigen in a polymersome, comprising the steps of: (i) dissolving an amphiphilic polymer of the present invention in chloroform, preferably the amphiphilic polymer is polybutadiene-polyethylene oxide (BD); (ii) drying the dissolved amphiphilic polymer to form a polymer film; (iii) adding a solubilized antigen to the dried amphiphilic polymer film of step (ii), wherein the antigen is selected from the group consisting of: (a) a polypeptide, preferably a polypeptide which is an antigen of the present invention; (b) a carbohydrate; (c) a combination of (a) and / or (b) and / or (c); (iv) rehydrating the polymer film of step (iii) to form a polymer vesicle; (v) optionally filtering the polymer vesicles of step (iv) to purify the polymer vesicles into monodisperse vesicles; and / or (vi) optionally isolating the polymer vesicles of step (iv) or step (v) from non-encapsulated antigen.

[0230] In some other aspects, the present invention relates to alternative methods for producing encapsulated antigens in polymersomes, including methods based on mixing a non-aqueous solution of a polymer into an aqueous solution of an antigen, sonication of the corresponding polymer-antigen mixed solution, or extrusion of the corresponding polymer-antigen mixed solution. Exemplary methods include those described in Rameez et al, Langmuir 2009 and Neil et al Langmuir 2009,25(16),9025-9029.

[0231] Compared to existing uptake and cross-presentation vehicles and methods based on them, the polymersomes of the invention have, inter alia, the following advantages, which are also aspects of the invention: The polymersomes are highly efficient in uptake and cross-presentation to the immune system. · Immune response is CD8 (+) including T cell-mediated immune responses, Polymersomes are oxidatively stable; - the humoral response is stronger than that generated by free antigen-based techniques with or without adjuvant; The immune response induced by the polymersomes of the present invention can be further boosted using adjuvants. The polymers of the polymersomes of the invention are inherently robust and can be adapted or functionalized to increase circulation time in the body; The polymersomes of the present invention are stable in the presence of serum components; Polymersome polymers are inexpensive and rapidly synthesized. The amount of antigen required to induce an immune response by the method of the present invention is less compared to free antigen-based techniques with or without adjuvant.

[0232] The present invention is also characterized by the following items. 1. A polymersome (e.g., an oxidatively stable polymersome containing a soluble encapsulated antigen), The soluble encapsulated antigen is (i) a polypeptide, (ii) carbohydrates, (iii) a polynucleotide, which is preferably not an antisense oligonucleotide, and more preferably is a DNA molecule or an mRNA molecule; (iv) a combination of (i) and / or (ii) and / or (iii) Selected from the group consisting of: Polymersomes. 2. Polymersomes bind to CD8 (+) The polymersome according to any one of the preceding paragraphs, having the ability to induce a T cell mediated immune response, preferably said induction being in vivo, ex vivo or in vitro. 3. The antigen comprises a soluble portion of a membrane protein (MP) or membrane associated peptide (MAP), preferably the antigen comprises a soluble portion of influenza hemagglutinin, porcine influenza hemagglutinin, ovalbumin (OVA), a spike protein, such as porcine epidemic diarrhea virus spike protein, a spike protein of a human pathogenic coronavirus, such as MERS-CoV spike protein, SARS-CoV-2 spike protein, or SARS-CoV-1 spike protein, B16 peptide or MC38 peptide, more preferably the antigen comprises a soluble portion of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:7, SEQ ID NO:8, SEQ ID NO:9, SEQ ID NO:10, SEQ ID NO:11, SEQ ID NO:12-14, SEQ ID NO:43-46, and SEQ ID NO:34-41, SEQ ID The polymersome of any one of the preceding paragraphs, comprising a polypeptide that is at least 60% or more (e.g., at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100%) identical to a polypeptide sequence selected from the group consisting of SEQ ID NO:48-51, SEQ ID NO:65. 4. The polymersome according to any one of the preceding paragraphs, wherein the polymersome is stable in the presence of serum components, preferably said stability being in vivo, ex vivo or in vitro. 5. The polymersome according to any one of the preceding paragraphs, wherein the polymersome is stable within an endosome, preferably said stability being in vivo, ex vivo or in vitro. 6. The polymersome according to any one of the preceding paragraphs, wherein the polymersome has improved oxidative stability compared to the corresponding oxidative stability of a liposome, preferably said improved stability being in vivo, ex vivo or in vitro. 7. Polymersomes release their contents, including soluble encapsulated antigens, in an oxidation-independent manner to target CD8 (+) The polymersome according to any one of the preceding paragraphs, having the ability to trigger a T cell mediated immune response, preferably wherein said release is in vivo, ex vivo or in vitro release. 8. Polymersomes Conjugates for CD8 (+) The polymersome according to any one of the preceding paragraphs, having the ability to induce a cellular immune response, including a T cell mediated immune response, preferably said immune response being an in vivo, ex vivo or in vitro immune response. 9. The polymersomes have the ability to induce a cellular and / or humoral immune response, and the cellular immune response is CD8 (+) The polymersome of any one of the preceding paragraphs, comprising a T cell mediated immune response, preferably wherein the immune response is an in vivo, ex vivo or in vitro immune response. 10. The polymersome according to any one of the preceding paragraphs, wherein the humoral immune response comprises the production of specific antibodies, more preferably said immune response is an in vivo, ex vivo or in vitro immune response. 11. Polymersomes bind to effector CD4 (+) The polymersome according to any one of the preceding paragraphs, having the ability to enhance the frequency of T cells, preferably said enhancement being in vivo, ex vivo or in vitro. 12. The polymersome according to any one of the preceding paragraphs, wherein the cellular immune response comprises a T cell mediated immune response, preferably said immune response is an in vivo, ex vivo or in vitro immune response. 13. Polymersomes increase antigen-specific CD8 activity compared to free antigen (+) The polymersome according to any one of the preceding paragraphs, having the ability to enhance clonal expansion of T cells, preferably wherein said expansion is in vivo, ex vivo or in vitro expansion. 14. Polymersomes bind antigen-specific effector CD8 (+) The polymersome according to any one of the preceding items, having the ability to induce T cells, preferably said induction being in vivo, ex vivo or in vitro. 15. Polymersomes bind antigen-specific CD8 (+) The polymersome according to any one of the preceding paragraphs, having the ability to enhance the cytotoxic phenotype of T cells, preferably said enhancement being in vivo, ex vivo or in vitro. 16. The polymersome according to any one of the preceding items, wherein the polymersome is capable of targeting lymph node resident macrophages and / or B cells, preferably said targeting being in vivo, ex vivo or in vitro targeting. 17. The polymersome according to any one of the preceding items, wherein the polymersome is reduction-stable, preferably the polymersome is reduction-stable in the presence of serum components, more preferably the reduction-stability is in vivo, ex vivo or in vitro. 18. The polymersome according to any one of the preceding items, wherein the polymersome has reduced permeability, preferably the reduced permeability is compared to the corresponding permeability of a liposome, and more preferably the permeability is in vivo, ex vivo or in vitro permeability. 19. The polymersome according to any one of the preceding items, wherein the polymersome is capable of releasing its contents within an endosome, preferably the endosome is a late endosome, and more preferably the release is in vivo, ex vivo or in vitro. 20. The polymersome of any one of the preceding paragraphs, having one or more of the following capabilities: (i) the ability to induce a cellular immune response, preferably the cellular immune response being CD8 (+) and more preferably, the cellular immune response is a CD8 (+)and most preferably the cellular immune response is a response to a soluble portion of influenza hemagglutinin, swine influenza hemagglutinin, ovalbumin (OVA), a spike protein, such as a porcine epidemic diarrhea virus spike protein, a spike protein of a human pathogenic coronavirus, such as a MERS-CoV spike protein, a SARS-CoV-2 spike protein, or a SARS-CoV-1 spike protein, a B16 peptide, or an MC38 peptide, and most preferably the cellular immune response is a response to a soluble portion of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:7, SEQ ID NO:8, SEQ ID NO:9, SEQ ID NO:10, SEQ ID NO:11, SEQ ID NO:12-14, SEQ ID NO:43-46, SEQ ID NO:34-41, SEQ ID NO:42-43, SEQ ID NO:44-45, SEQ ID NO:46-47, SEQ ID NO:48-49, SEQ ID NO:50-51, SEQ ID NO:52-53, SEQ ID NO:54-55, SEQ ID NO:56-57, SEQ ID NO:58-59, SEQ ID NO:59-60, SEQ ID NO:61-62, SEQ ID NO:63-64, SEQ ID NO:64-65, SEQ ID NO:65-66, SEQ ID NO:66-70, SEQ ID NO:67-71, SEQ ID NO:68-82, SEQ ID NO:69-90, SEQ ID NO:71-92, SEQ ID NO:73-74, SEQ ID NO:75-76, SEQ ID NO:77-83, SEQ ID NO:78-84, SEQ ID NO:79- the ability to elicit a cellular immune response in response to a polypeptide that is at least 60% or more (e.g., at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100%) identical to a polypeptide sequence selected from the group consisting of SEQ ID NOs:48-51, and SEQ ID NO:65; (ii) the ability to release polymersome contents within an endosome, preferably the endosome is a late endosome, more preferably the contents comprises influenza hemagglutinin, swine influenza hemagglutinin, ovalbumin (OVA), a spike protein, such as porcine epidemic diarrhea virus spike protein, a spike protein of a human pathogenic coronavirus, such as MERS-CoV spike protein, SARS-CoV-2 spike protein, or SARS-CoV-1 spike protein, a soluble portion of a B16 peptide or an MC38 peptide, most preferably the contents comprises a soluble portion of a peptide selected from the group consisting of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:7, SEQ ID NO:8, SEQ ID NO:9, SEQ ID NO:10, SEQ ID NO:11, SEQ ID NO:12-14, SEQ ID NO:43-46, SEQ ID NO:47-48, SEQ ID NO:49-50, SEQ ID NO:51-52, SEQ ID NO:53-54, SEQ ID NO:55-56, SEQ ID NO:57-58, SEQ ID NO:59-60, SEQ ID NO:61-62, SEQ ID NO:63-64, SEQ ID NO:64-65, SEQ ID NO:65-66, SEQ ID NO:66-67, SEQ ID NO:67-68, SEQ ID NO:68-69, SEQ ID NO:69-70, SEQ ID NO:69-81, SEQ ID NO:69-82, SEQ ID NO:69-90, SEQ ID NO:71-83, SEQ ID NO:72-84, SEQ ID NO:73-85, SEQ ID NO:74-86, SEQ ID NO:75-87, SEQ ID NO: the ability to release polymersome contents within an endosome comprising a polypeptide that is at least 60% or more (e.g., at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100%) identical to a polypeptide sequence selected from the group consisting of SEQ ID NOs:34-41, SEQ ID NOs:48-51, and SEQ ID NO:65; (iii) Oxidation-independent release of polymersome contents to CD8 (+)and the ability to trigger a T cell mediated immune response, preferably the content comprises a soluble portion of influenza hemagglutinin, swine influenza hemagglutinin, ovalbumin (OVA), a spike protein, such as a porcine epidemic diarrhea virus spike protein, a spike protein of a human pathogenic coronavirus, such as a MERS-CoV spike protein, a SARS-CoV-2 spike protein, or a SARS-CoV-1 spike protein, a B16 peptide or an MC38 peptide, more preferably the content comprises a soluble portion of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:7, SEQ ID NO:8, SEQ ID NO:9, SEQ ID NO:10, SEQ ID NO:11, SEQ ID NO:12-14, SEQ ID NO:43-46, SEQ ID NO:34-41, SEQ ID NO:42-43, SEQ ID NO:44-45, SEQ ID NO:46-47, SEQ ID NO:48-49, SEQ ID NO:50-51, SEQ ID NO:52-53, SEQ ID NO:54-55, SEQ ID NO:56-57, SEQ ID NO:58-59, SEQ ID NO:59-60, SEQ ID NO:61-62, SEQ ID NO:63-64, SEQ ID NO:64-65, SEQ ID NO:65-66, SEQ ID NO:66-70, SEQ ID NO:67-71, SEQ ID NO:68-82, SEQ ID NO:69-90, SEQ ID NO:71-92, SEQ ID NO:73-74, SEQ ID NO:75-76, SEQ ID NO:77-83, SEQ ID NO:78-84, SEQ ID NO:79-91, and SEQ ID NO:48-51, and SEQ ID NO:65. (+) the ability to trigger a T cell-mediated immune response; (iv) the ability to stimulate an immune response against an antigen, preferably the antigen comprises a soluble portion of influenza hemagglutinin, swine influenza hemagglutinin, ovalbumin (OVA), a spike protein, such as a porcine epidemic diarrhea virus spike protein, a spike protein of a human pathogenic coronavirus, such as a MERS-CoV spike protein, a SARS-CoV-2 spike protein, or a SARS-CoV-1 spike protein, a B16 peptide or an MC38 peptide, more preferably the antigen comprises a soluble portion of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:7, SEQ ID NO:8, SEQ ID NO:9, SEQ ID NO:10, SEQ ID NO:11, SEQ ID NO:12-14, SEQ ID NOs:43-46, SEQ ID NOs:34-41, SEQ ID the ability to stimulate an immune response to an antigen, including a polypeptide that is at least 60% or more (e.g., at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100%) identical to a polypeptide sequence selected from the group consisting of SEQ ID NOs:48-51, and SEQ ID NO:65; (v) CD8 (+)The ability to trigger cross-protection induced by a T cell-mediated immune response, preferably the response is a response to influenza hemagglutinin, swine influenza hemagglutinin, a spike protein, such as porcine epidemic diarrhea virus spike protein, a spike protein of a human pathogenic coronavirus, such as MERS-CoV spike protein, SARS-CoV-2 spike protein, or SARS-CoV-1 spike protein, ovalbumin (OVA), a soluble portion of B16 peptide or MC38 peptide, more preferably the response is a response to SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:7, SEQ ID NO:8, SEQ ID NO:9, SEQ ID NO:10, SEQ ID NO:11 and SEQ ID NOs:12-14, SEQ ID NOs:43-46, SEQ ID NOs:34-41, SEQ ID NOs:42-43, SEQ ID NOs:44-45, SEQ ID NOs:46-47, SEQ ID NOs:48-49, SEQ ID NOs:50-53, SEQ ID NOs:54-54, SEQ ID NOs:55-56, SEQ ID NOs:57-58, SEQ ID NOs:59-60, SEQ ID NOs:61-62, SEQ ID NOs:63-64, SEQ ID NOs:64-65, SEQ ID NOs:65-66, SEQ ID NOs:66-67, SEQ ID NOs:67-70, SEQ ID NOs:68-71, SEQ ID NOs:69-82, SEQ ID NOs:72-73, SEQ ID NOs:74-74, SEQ ID NOs:75-76, SEQ ID NOs:77-78, SEQ ID NOs:79 and a polypeptide that is at least 60% or more (e.g., at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100%) identical to a polypeptide sequence selected from the group consisting of SEQ ID NO:48-51, and SEQ ID NO:65. (+) the ability to trigger cross-protection induced by T cell-mediated immune responses; (vi) the ability to deliver a peptide or protein to an antigen presenting cell (APC), preferably the peptide or protein comprises or is derived from a soluble portion of influenza hemagglutinin, swine influenza hemagglutinin, ovalbumin (OVA), a spike protein, such as porcine epidemic diarrhea virus spike protein, a spike protein of a human pathogenic coronavirus, such as MERS-CoV spike protein, SARS-CoV-2 spike protein, or SARS-CoV-1 spike protein, a B16 peptide or an MC38 peptide, more preferably the peptide or protein is selected from the group consisting of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:7, SEQ ID NO:8, SEQ ID NO:9, SEQ ID NO:10, SEQ ID NO:11 and SEQ ID NOs:12-14, SEQ ID NOs:43-46, SEQ ID NOs:47-48, SEQ ID NOs:49-50, SEQ ID NOs:51-52, SEQ ID NOs:53-54, SEQ ID NOs:55-56, SEQ ID NOs:57-58, SEQ ID NOs:59-60, SEQ ID NOs:61-62, SEQ ID NOs:63-64, SEQ ID NOs:64-65, SEQ ID NOs:65-66, SEQ ID NOs:66-67, SEQ ID NOs:67-68, SEQ ID NOs:68-70, SEQ ID NOs:69-71, SEQ ID NOs:69-82, SEQ ID NOs:69-83, SEQ ID NOs:69-84, SEQ ID NOs:69-85, SEQ ID NOs:72-73, SEQ ID NOs:69-86, SEQ ID NOs:69 the ability to deliver a peptide or protein to an antigen presenting cell, comprising or derived from a polypeptide that is at least 60% or more (e.g., at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100%) identical to a polypeptide sequence selected from the group consisting of SEQ ID NOs:34-41, SEQ ID NOs:48-51, and SEQ ID NO:65; (vii) CD8 (+) T cell-mediated immune response and / or CD4 (+)and the ability to trigger an immune response, including a T cell mediated immune response, preferably the response is a response to a soluble portion of influenza hemagglutinin, swine influenza hemagglutinin, ovalbumin (OVA), a spike protein, such as a porcine epidemic diarrhea virus spike protein, a spike protein of a human pathogenic coronavirus, such as a MERS-CoV spike protein, a SARS-CoV-2 spike protein, or a SARS-CoV-1 spike protein, a B16 peptide or an MC38 peptide, more preferably the response is a response to a soluble portion of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:7, SEQ ID NO:8, SEQ ID NO:9, SEQ ID NO:10, SEQ ID NO:11 and SEQ ID NOs:12-14, SEQ ID NOs:43-46, SEQ ID NOs:34-41, SEQ ID and a polypeptide that is at least 60% or more (e.g., at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100%) identical to a polypeptide sequence selected from the group consisting of SEQ ID NO:48-51, and SEQ ID NO:65. (+) T cell-mediated immune response and / or CD4 (+) the ability to trigger immune responses, including T cell-mediated immune responses; (viii) the ability to stimulate an immune response in a subject, preferably the response is a response to a soluble portion of influenza hemagglutinin, swine influenza hemagglutinin, ovalbumin (OVA), a spike protein, such as a porcine epidemic diarrhea virus spike protein, a spike protein of a human pathogenic coronavirus, such as a MERS-CoV spike protein, a SARS-CoV-2 spike protein, or a SARS-CoV-1 spike protein, a B16 peptide or an MC38 peptide, more preferably the response is a response to a soluble portion of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:7, SEQ ID NO:8, SEQ ID NO:9, SEQ ID NO:10, SEQ ID NO:11 and SEQ ID NOs:12-14, SEQ ID NOs:43-46, SEQ ID NOs:34-41, SEQ ID the ability to stimulate an immune response in a subject to a polypeptide that is at least 60% or more (e.g., at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100%) identical to a polypeptide sequence selected from the group consisting of SEQ ID NOs:48-51, and SEQ ID NO:65; (ix) the ability to immunize a non-human animal, preferably the immunization is against influenza hemagglutinin, swine influenza hemagglutinin, ovalbumin (OVA), a spike protein, such as a porcine epidemic diarrhea virus spike protein, a spike protein of a human pathogenic coronavirus, such as a MERS-CoV spike protein, a SARS-CoV-2 spike protein, or a SARS-CoV-1 spike protein, a soluble portion of a B16 peptide or an MC38 peptide, more preferably the immunization is against a soluble portion of ... the ability to immunize a non-human animal against a polypeptide that is at least 60% or more (e.g., at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100%) identical to a polypeptide sequence selected from the group consisting of SEQ ID NO:48-51, and SEQ ID NO:65; (x) the polymersome has an altered antigenicity compared to the corresponding antigenicity of the antigen without the polymersome, preferably the antigen is influenza hemagglutinin, porcine influenza hemagglutinin, ovalbumin (OVA), a spike protein, such as porcine epidemic diarrhea virus spike protein, a spike protein of a human pathogenic coronavirus, such as MERS-CoV spike protein, SARS-CoV-2 spike protein, or SARS-CoV-1 spike protein, a soluble portion of a B16 peptide or an MC38 peptide, more preferably the antigen is selected from the group consisting of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:7, SEQ ID NO:8, SEQ ID NO:9, SEQ ID NO:10, SEQ ID NO:11 and SEQ ID NOs:12-14, SEQ ID NOs:43-46, SEQ ID NOs:47-48, SEQ ID NOs:49-50, SEQ ID NOs:51-52, SEQ ID NOs:53-54, SEQ ID NOs:55-56, SEQ ID NOs:57-58, SEQ ID NOs:59-60, SEQ ID NOs:61-62, SEQ ID NOs:63-64, SEQ ID NOs:64-65, SEQ ID NOs:65-66, SEQ ID NOs:66-67, SEQ ID NOs:67-68, SEQ ID NOs:68-70, SEQ ID NOs:69-71, SEQ ID NOs:69-72, SEQ ID NOs:73-73, SEQ ID NOs:74-74, SEQ ID NOs:75-75, SEQ ID NOs:76-76, SEQ ID NOs:77-78, SEQ ID NOs:79 having altered antigenicity, which is a polypeptide that is at least 60% or more (e.g., at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100%) identical to a polypeptide sequence selected from the group consisting of SEQ ID NOs:34-41, SEQ ID NOs:48-51, and SEQ ID NO:65; (xi) the polymersome has an altered immunogenicity compared to the corresponding immunogenicity of the antigen without the polymersome, preferably the immunogen is influenza hemagglutinin, porcine influenza hemagglutinin, ovalbumin (OVA), a spike protein, such as porcine epidemic diarrhea virus spike protein, a spike protein of a human pathogenic coronavirus, such as MERS-CoV spike protein, SARS-CoV-2 spike protein, or SARS-CoV-1 spike protein, a soluble portion of a B16 peptide or an MC38 peptide, more preferably the immunogen is SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:7, SEQ ID NO:8, SEQ ID NO:9, SEQ ID NO:10, SEQ ID NO:11 and SEQ ID NOs:12-14, SEQ ID NOs:43-46, SEQ ID NOs:47-48, SEQ ID NOs:49-50, SEQ ID NOs:51-52, SEQ ID NOs:53-54, SEQ ID NOs:55-56, SEQ ID NOs:57-58, SEQ ID NOs:59-60, SEQ ID NOs:61-62, SEQ ID NOs:63-64, SEQ ID NOs:64-65, SEQ ID NOs:65-66, SEQ ID NOs:66-67, SEQ ID NOs:67-68, SEQ ID NOs:68-70, SEQ ID NOs:69-71, SEQ ID NOs:69-72, SEQ ID NOs:73-73, SEQ ID NOs:74-74, SEQ ID NOs:75-75, SEQ ID NOs:76-76, SEQ ID NOs:77-78, SEQ ID NOs:79-80, and having altered immunogenicity, wherein the polypeptide is at least 60% or more (e.g., at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100%) identical to a polypeptide sequence selected from the group consisting of SEQ ID NOs:34-41, SEQ ID NOs:48-51, and SEQ ID NO:65. 21. The polymersome of any one of the preceding paragraphs, having one or more of the following characteristics: (i) the polymersome comprises an oxidatively stable membrane, and / or (ii) the polymersome is synthetic, and / or (iii) the polymersomes are free of non-encapsulated antigen or are mixed with free non-encapsulated antigen, and / or (iv) the polymersome comprises a membrane of an amphiphilic polymer; and / or (v) the polymersome comprises an amphiphilic synthetic block copolymer that forms a vesicle membrane; and / or (vi) the polymersome has a diameter of more than 70 nm, preferably in the range of about 100 nm to about 1 μm, or about 120 nm to about 250 nm, or about 125 nm to about 250 nm, about 140 nm to about 240 nm, about 150 nm to about 235 nm, about 170 nm to about 230 nm, or about 220 nm to about 180 nm, or about 190 nm to about 210 nm; and / or (vii) the polymersome has a vesicle morphology; (viii) The polymersomes are self-assembling. 22. The polymersome according to item 21, wherein the polymersome is in the form of a polymersome aggregate, and the average diameter of the polymersome aggregate is in the range of about 100 nm to about 1 μm, or about 100 nm to about 750 nm, or about 100 nm to about 500 nm, or about 120 nm to about 250 nm, or about 125 nm to about 250 nm, about 140 nm to about 240 nm, about 150 nm to about 235 nm, about 170 nm to about 230 nm, or about 220 nm to about 180 nm, or about 190 nm to about 210 nm. 23. The polymersome of any one of the preceding claims, wherein the antigen is an immunogen. 24. The polymersome of any one of the preceding claims, wherein the antigen is selected from the group consisting of (i) an autoantigen, (ii) a non-self antigen, (iii) a non-self immunogen, and (iv) an autoimmunogen. 25. The antigen is: (i) a polypeptide that is at least 80% or more (e.g., at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100%) identical to a viral polypeptide sequence, preferably the viral polypeptide sequence is influenza hemagglutinin or swine influenza hemagglutinin, and more preferably the viral polypeptide sequence is selected from the group consisting of SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:7 and SEQ ID NO:8; (ii) a polypeptide that is at least 80% or more identical (e.g., at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100%) to a bacterial polypeptide sequence; (iii) a polypeptide having at least 80% or more (e.g., at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100%) identical to a mammalian or avian polypeptide sequence, preferably the mammalian or avian polypeptide sequence is a polypeptide having at least 80% or more (e.g., at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100%) identical to ovalbumin (OVA), spike protein, B16 peptide or MC38 peptide, more preferably the mammalian or avian polypeptide sequence is SEQ ID NO:4, SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:9, SEQ ID NO:10, SEQ ID NO:11 and SEQ ID NOs:12-14, SEQ ID NOs:43-46, SEQ ID NOs:47-48, SEQ ID NOs:49-50, SEQ ID NOs:51-52, SEQ ID NOs:53-54, SEQ ID NOs:55-56, SEQ ID NOs:57-58, SEQ ID NOs:59-60, SEQ ID NOs:61-62, SEQ ID NOs:63-64, SEQ ID NOs:64-66, SEQ ID NOs:65-68, SEQ ID NOs:66-69, SEQ ID NOs:67-70, SEQ ID NOs:68-71, SEQ ID NOs:69-82, SEQ ID NOs:69-91, SEQ ID NOs:72-73, SEQ ID NOs:74-74, SEQ ID NOs:75-75, SEQ ID NOs:76-76, SEQ ID NO A polypeptide selected from the group consisting of SEQ ID NOs: 34-41, 48-51, and 65. The polymersome of any one of the preceding claims, selected from the group consisting of: 26. The polymersome of any one of the preceding claims, wherein the mammalian polypeptide sequence is selected from the group consisting of human, rodent, rabbit and horse polypeptide sequences. 27. The polymersome of any one of the preceding claims, wherein the antigen is an antibody or a fragment thereof. 28. The antigen is: (i) influenza hemagglutinin (HA), preferably selected from the group consisting of SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:7 and SEQ ID NO:8; (ii) swine influenza hemagglutinin (HA), preferably SEQ ID NO:6; (iii) ovalbumin (OVA), preferably SEQ ID NO:4; (iv) a spike protein, such as a porcine epidemic diarrhea virus (PED) spike protein, a spike protein of a human pathogenic coronavirus, such as a MERS-CoV spike protein, a SARS-CoV-2 spike protein, or a SARS-CoV-1 spike protein, preferably SEQ ID NOs: 12-14, 43-46, 34-41, 48-51, and 65; (v) B16 peptide, preferably selected from the group consisting of SEQ ID NO:9, SEQ ID NO:10 and SEQ ID NO:11; (vi) MC38 peptides, preferably selected from the group consisting of SEQ ID NO:1, SEQ ID NO:2 and SEQ ID NO:3; (vii) B16 peptide and MC38 peptide, preferably the peptide is independently selected from the group: (i) SEQ ID NO: 1-3 and (ii) SEQ ID NO: 9-11; The polymersome of any one of the preceding claims, selected from the group consisting of: 29. The polymersome of any one of the preceding claims, selected from the group consisting of cationic, anionic and nonionic polymersomes, and mixtures thereof. 30. The polymersome according to any one of the preceding items, wherein the block copolymer or amphiphilic polymer is essentially non-immunogenic or essentially non-antigenic, preferably the block copolymer or amphiphilic polymer is non-immunogenic or non-antigenic. 31. The polymersome of any one of the preceding claims, wherein the block copolymer or amphiphilic polymer is oxidatively stable. 32. The polymersome of any one of the preceding claims, wherein the block copolymer or amphiphilic polymer is not an immunostimulant or adjuvant. 33. The polymersome of any one of the preceding claims, wherein the amphiphilic polymer comprises a diblock or triblock (ABA or ABC) copolymer. 34. The polymersome of any one of the preceding items, wherein the amphiphilic polymer comprises the copolymer poly(N-vinylpyrrolidone)-b-PLA. 35. The polymersome of any one of the preceding paragraphs, wherein the amphiphilic polymer comprises at least one carboxylic acid, amide, amine, alkylene, dialkylsiloxane, ether, or alkylene sulfide monomer unit. 36. The polymersome of any one of the preceding paragraphs, wherein the amphiphilic polymer is a polyether block selected from the group consisting of an oligo(oxyethylene) block, a poly(oxyethylene) block, an oligo(oxypropylene) block, a poly(oxypropylene) block, an oligo(oxybutylene) block, and a poly(oxybutylene) block. 37. The polymersome of any one of the preceding claims, wherein the amphiphilic polymer is a poly(butadiene)-poly(ethylene oxide) (PB-PEO) diblock copolymer. 38. The polymersome of any one of the preceding items, wherein the PB-PEO diblock copolymer comprises 5-50 block PB and 5-50 block PEO. 39. The polymersome according to any one of the preceding items, wherein the amphiphilic polymer is a poly(dimethylsiloxane)-poly(ethylene oxide) (PDMS-PEO) diblock copolymer, preferably the PB-PEO diblock copolymer preferably comprising 5-100 blocks PDMS and 5-100 blocks PEO. 40. A polymersome according to any one of the preceding items, wherein the polymersome may be composed of block copolymers or amphiphilic polymers alone or may be composed of block copolymers or amphiphilic polymers mixed with lipids. 41. The polymersome of any one of the preceding items, wherein the lipid is composed of a synthetic or natural lipid, or a mixture of synthetic or natural lipids, or a combination of synthetic and natural lipids. 42. The polymersome of any one of the preceding paragraphs, wherein the amphiphilic polymer is a poly(lactide)-poly(ethylene oxide) / 1-palmitoyl-2-oleyl-sn-glycero-3-phospho-L-serine (PLA-PEO / POPC) copolymer, preferably the PLA-PEO / POPC has a ratio of PLA-PEO to POPC (e.g., PLA-PEO / POPC) of 50:50 or more (e.g., 50 / 50 or 75 / 25 or 90 / 10). 43. The polymersome of any one of the preceding paragraphs, wherein the amphiphilic polymer is a poly(caprolactone)-poly(ethylene oxide) / 1-palmitoyl-2-oleyl-sn-glycero-3-phospho-L-serine (PCL-PEO / POPC) copolymer, preferably having a ratio of PCL-PEO to POPC (e.g., PCL-PEO / POPC) of 50:50 or more (e.g., 50 / 50 or 75 / 25 or 90 / 10). 44. The polymersome of any one of the preceding items, wherein the amphiphilic polymer is polybutadiene-polyethylene oxide (BD) or poly(dimethylsiloxane)-poly(ethylene oxide) (PDMS-PEO) diblock copolymer or poly(dimethylsiloxane)-poly(acrylic acid) (PDMS-PAA) diblock copolymer. 45. Polymersomes are made of diblock copolymers (PBD 21 -PEO 14 (herein referred to as "BD21"), PDMS 47 -PEO 36 (PDMS-PEO) or triblock copolymer PMOXA 12 -PDMS 55 -PMOXA 12 The polymersome of any one of the preceding items, comprising: 46. ​​The polymersome of any one of the preceding paragraphs, comprising one or more compartments. 47. The polymersome according to any one of the preceding items, wherein the polymersome comprises one or more compartments, each of the one or more compartments encapsulating at least one peptide, protein, and nucleic acid, preferably wherein the at least one of the peptide, protein, and nucleic acid is immunogenic or antigenic, and more preferably wherein each of the one or more compartments is composed of the same or different amphiphilic polymers. 48. A polymersome comprising two or more compartments, the compartments comprising an outer block copolymer vesicle and at least one inner block copolymer vesicle, the at least one inner block copolymer vesicle being encapsulated within the outer block copolymer vesicle, preferably the outer block copolymer vesicle is (i) poly[styrene-b-poly(L-isocyanoalanine(2-thiophen-3-yl-ethyl)amide)] (PS-PIAT), (ii) poly(butadiene)-poly(ethylene oxide) (PBD-PEO); (iii) poly(ethylene oxide)-poly(caprolactone) (PEO-PCL); (iv) poly(ethylethylene)-poly(ethylene oxide) (PEE-PEO); (v) poly(ethylene oxide)-poly(lactic acid) (PEO-PLA); (vi) poly(isoprene)-poly(ethylene oxide) (PI-PEO); (vii) poly(2-vinylpyridine)-poly(ethylene oxide) (P2VP-PEO); (viii) poly(ethylene oxide)-poly(N-isopropylacrylamide) (PEO-PNIPAm); (ix) poly(styrene)-poly(acrylic acid) (PS-PAA); (x) poly(ethylene glycol)-polypropylene sulfide (PEG-PPS); (xi) poly(2-methyloxazoline)-poly(dimethylsiloxane)-poly(2-methyloxazoline) (PMOXA-PDMS-PMOXA); (xii) poly(ethylene oxide)-poly(dimethylsiloxane)-poly(2-methyloxazoline) (PEO-PDMS-PMOXA); (xiii) poly(methylphenylsilane)-poly(ethylene oxide) (PMPS-PEO-PMPS-PEO-PMPS), and (xiv) Poly(dimethylsiloxane)-poly(acrylic acid) (PDMS-PAA) and more preferably, the at least one inner block copolymer vesicle is a polymersome formed of a copolymer independently selected from the group consisting of (xv) poly[styrene-b-poly(L-isocyanoalanine(2-thiophen-3-yl-ethyl)amide)] (PS-PIAT); (xvi) poly(butadiene)-poly(ethylene oxide) (PBD-PEO); (xvii) poly(ethylene oxide)-poly(caprolactone) (PEO-PCL); (xviii) poly(ethylethylene)-poly(ethylene oxide) (PEE-PEO); (xix) poly(ethylene oxide)-poly(lactic acid) (PEO-PLA); (xx) poly(isoprene)-poly(ethylene oxide) (PI-PEO); (xxi) Poly(2-vinylpyridine)-poly(ethylene oxide) (P2VP-PEO); (xxii) Poly(ethylene oxide)-poly(N-isopropylacrylamide) (PEO-PNIPAm); (xxiii) poly(styrene)-poly(acrylic acid) (PS-PAA); (xxiv) poly(ethylene glycol)-polypropylene sulfide (PEG-PPS); (xxv) poly(2-methyloxazoline)-poly(dimethylsiloxane)-poly(2-methyloxazoline) (PMOXA-PDMS-PMOXA); (xxvi) Poly(ethylene oxide)-poly(dimethylsiloxane)-poly(2-methyloxazoline) (PEO-PDMS-PMOXA); (xxvii) poly(methylphenylsilane)-poly(ethylene oxide) (PMPS-PEO-PMPS-PEO-PMPS), and (xxviii) Poly(dimethylsiloxane)-poly(acrylic acid) (PDMS-PAA) The polymersome of any one of the preceding claims, which is a polymersome formed from a copolymer independently selected from the group consisting of: 49. The polymersome of any one of the preceding items, comprising a lipid polymer. 50. The polymersome of any one of the preceding claims, further comprising an encapsulated adjuvant. 51. A method for producing an encapsulated antigen in a polymersome, comprising the steps of: (i) dissolving an amphiphilic polymer in chloroform, preferably the amphiphilic polymer is polybutadiene-polyethylene oxide (BD); (ii) drying the dissolved amphiphilic polymer to form a polymer film; (iii) adding a solubilized antigen to the dry amphiphilic polymer film of step (ii), wherein the antigen is (a) a polypeptide, preferably the polypeptide antigen is as described in any one of the preceding items, more preferably the polypeptide antigen comprises influenza hemagglutinin, porcine influenza hemagglutinin, ovalbumin (OVA), a spike protein, such as porcine epidemic diarrhea virus spike protein, a spike protein of a human pathogenic coronavirus, such as MERS-CoV spike protein, SARS-CoV-2 spike protein, or SARS-CoV-1 spike protein, a soluble portion of a B16 peptide or an MC38 peptide, most preferably the polypeptide antigen is selected from the group consisting of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:7, SEQ ID NO:8, SEQ ID NO:9, SEQ ID NO:10, SEQ ID NO:11 and SEQ ID NOs:12-14, SEQ ID NOs:43-46, SEQ ID NOs:34-41, SEQ ID NOs:35-38, SEQ ID NOs:36-39, SEQ ID NOs:37-42, SEQ ID NOs:38-43, SEQ ID NOs:39-51, SEQ ID NOs:39-52, SEQ ID NOs:39-44, SEQ ID NOs:39-53, SEQ ID NOs:39-54, SEQ ID NOs:39-55, SEQ ID NOs:39-46, SEQ ID NOs:39-54, SEQ ID NOs:39-55, SEQ ID NOs:39-47, SEQ ID NOs:39-56, SEQ ID NOs:39-48, SEQ ID NOs:39-57, SEQ ID NOs:48-49, SEQ ID NOs:48-59, SEQ ID NOs:48-59, SEQ ID NOs:48-59, a polypeptide that is at least 60% or more (e.g., at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100%) identical to a polypeptide sequence selected from the group consisting of SEQ ID NOs:48-51, and SEQ ID NO:65; (b) carbohydrates, (c) a polynucleotide which is not an antisense oligonucleotide and is preferably a DNA molecule or an mRNA molecule; (d) a combination of (a) and / or (b) and / or (c) A step selected from the group consisting of: (iv) rehydrating the polymer film of step (iii) to form polymer vesicles; (v) optionally filtering the polymer vesicles of step (iv) to purify the polymer vesicles into monodisperse vesicles; and / or (vi) optionally isolating the polymer vesicles of step (iv) or step (v) from unencapsulated antigen. 52. A method for producing an encapsulated antigen in a polymersome according to any one of the preceding items, wherein the polymersome is a polymersome according to any one of the preceding items. 53. A polymersome produced by the method for producing an encapsulated antigen in a polymersome described in any one of the preceding items. 54. A composition comprising a polymersome according to any one of the preceding items. 55. The composition according to any one of the preceding items, which is a pharmaceutical composition or a diagnostic composition. 56. The composition according to any one of the preceding items, which is an immunogenic composition, an antigenic composition or an immunotherapeutic composition. 57. The composition of any one of the preceding items, further comprising one or more immunostimulants and / or one or more adjuvants. 58. The composition of any one of the preceding items, which is a vaccine. 59. The composition of any one of the preceding items, formulated for intradermal, intraperitoneal, intramuscular, subcutaneous, intravenous injection, or non-invasive administration to a mucosal surface. 60. An isolated antigen-presenting cell or hybridoma cell exposed to a polymersome or composition according to any one of the preceding items. 61. The antigen-presenting cell of any one of the preceding items, comprising a dendritic cell. 62. The antigen-presenting cell of any one of the preceding items, comprising a macrophage. 63. The antigen-presenting cell of any one of the preceding items, comprising a B cell. 64. A vaccine comprising the polymersome, composition, antigen-presenting cell or hybridoma according to any one of the preceding items, and further comprising a pharma- ceutically acceptable excipient or carrier. 65. (i) the antigen comprises influenza hemagglutinin (HA) and the vaccine is an influenza vaccine, preferably the influenza hemagglutinin (HA) is at least 60% or more (e.g. at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100%) identical to a polypeptide selected from the group consisting of SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:7 and SEQ ID NO:8; (ii) the antigen comprises swine influenza hemagglutinin (HA) and the vaccine is a swine influenza vaccine, preferably the swine influenza hemagglutinin (HA) is at least 60% or more (e.g. at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100%) identical to SEQ ID NO:6; (iii) the antigen comprises ovalbumin (OVA) and the vaccine is a cancer vaccine, preferably the ovalbumin (OVA) is at least 60% or more (e.g., at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100%) identical to SEQ ID NO:4; (iv) the antigen comprises a spike protein (PEDv S) and the vaccine is a PED vaccine, preferably the porcine epidemic diarrhea virus spike protein (S protein) is at least 80% or more (e.g., at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100%) identical to a polypeptide of SEQ ID NO:12-14; (v) the antigen comprises a B16 peptide and the vaccine is a cancer vaccine, preferably the peptide is selected from the group consisting of SEQ ID NOs: 9 to 11; (vi) The antigen comprises an MC38 peptide, and the vaccine is a cancer vaccine, preferably the peptide is selected from the group consisting of SEQ ID NO: 1 to 3; (vii) the antigen comprises a B16 peptide and an MC38 peptide, and the vaccine is a cancer vaccine, preferably the peptides are independently selected from the group: (i) SEQ ID NOs: 1-3 and (ii) SEQ ID NOs: 9-11; (viii) the antigen is at least 60% or more (e.g., at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100%) identical to a polypeptide sequence selected from the group consisting of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:9, SEQ ID NO:10, SEQ ID NO:11, and the vaccine is a cancer vaccine. (ix) the antigen comprises a MERS-CoV spike protein, a SARS-CoV-2 spike protein, or a SARS-CoV-1 spike protein that is at least 60% or more (e.g., at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100%) identical to a polypeptide sequence selected from the group consisting of SEQ ID NOs:43-46, SEQ ID NOs:34-41, SEQ ID NOs:48-51 and SEQ ID NO:65, and the vaccine is against a human pathogenic coronavirus, such as MERS-CoV, SARS-CoV-2 or SARS-CoV-1; The vaccine according to any one of the preceding items. 66. A kit comprising the polymersome, composition, antigen-presenting cell, hybridoma or vaccine described in any one of the preceding items. 67. A method for inducing an immune response in a subject (e.g., a human), comprising the steps of: (i) providing to said subject a polymersome, composition, antigen presenting cell, hybridoma or vaccine according to any one of the preceding paragraphs; (ii) administering the polymersome, composition, antigen presenting cell, hybridoma or vaccine to the subject, preferably wherein the administration is by intradermal, intraperitoneal, intramuscular, subcutaneous, intravenous injection, or non-invasive administration to a mucosal surface. 68. The method of inducing an immune response according to any one of the preceding items, wherein the immune response is a broad immune response. 69. Immune response is CD8 (+) T cell-mediated immune response and / or CD4 (+) A method of eliciting an immune response according to any one of the preceding paragraphs, comprising a T cell mediated immune response. 70. A method for treating or preventing an infectious disease, cancer or autoimmune disease in a subject (e.g., a human) in need thereof, comprising administering to the subject a therapeutically effective amount of a polymersome, composition, antigen-presenting cell, hybridoma or vaccine described in any one of the preceding items, preferably wherein the infectious disease is a viral or bacterial infectious disease. 71. A method for immunizing a non-human animal, comprising the steps of: (i) providing a polymersome, composition, antigen presenting cell, hybridoma or vaccine according to any one of the preceding paragraphs; (ii) immunizing a non-human animal with the polymersome, composition, antigen presenting cell, hybridoma or vaccine. 72. A method for preparing an antibody, comprising the steps of: (i) immunizing a non-human mammal with the polymersome, composition, antigen presenting cell, hybridoma or vaccine according to any one of the preceding paragraphs; (ii) isolating the antibody obtained in step (i). 73. The method of any one of the preceding items, wherein the antibody is a monoclonal antibody (mAb). 74. A polymersome, composition, antigen-presenting cell, hybridoma or vaccine according to any one of the preceding items for use as a medicament. 75. The polymersome, composition, antigen presenting cell, hybridoma or vaccine of any one of the preceding paragraphs for use in one or more of the following methods: (i) methods for discovering and / or screening and / or preparing antibodies; (ii) methods for discovering and / or screening and / or preparing vaccines; (iii) a method for producing or preparing an immunogenic or immunostimulatory composition; (iv) A method for targeted delivery of a protein and / or peptide, preferably the targeted delivery is targeted delivery of an antigenic protein and / or peptide according to any one of the preceding items, further preferably the antigenic protein and / or peptide comprises a soluble portion of a membrane protein (MP) or a membrane associated peptide (MAP), most preferably the antigen comprises a soluble portion of influenza hemagglutinin, porcine influenza hemagglutinin, ovalbumin (OVA), a spike protein, such as porcine epidemic diarrhea virus spike protein, a spike protein of a human pathogenic coronavirus, such as MERS-CoV spike protein, SARS-CoV-2 spike protein or SARS-CoV-1 spike protein, B16 peptide or MC38 peptide, further most preferably the antigen comprises a soluble portion of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:7, SEQ ID NO:8, SEQ ID NO:9, SEQ ID NO:10, SEQ ID NO:11, SEQ ID NO:12, SEQ ID NO:13, SEQ ID NO:14, SEQ ID NO:15, SEQ ID NO:16, SEQ ID NO:17, SEQ ID NO:18, SEQ ID NO:19, SEQ ID NO:20, SEQ ID NO:21, SEQ ID NO:22, SEQ ID NO:23, SEQ ID NO:24, SEQ ID NO:25, SEQ ID NO:26, SEQ ID NO:27, SEQ ID NO:28, SEQ ID NO:29, SEQ ID NO:30, SEQ ID NO:31, SEQ ID NO:32, SEQ ID NO:33, SEQ ID NO:34, SEQ ID NO:35, SEQ ID NO:36, SEQ ID NO:37, SEQ ID NO:38, SEQ ID NO:39, SEQ ID NO:40, SEQ ID NO:41, SEQ ID a polypeptide sequence selected from the group consisting of SEQ ID NO:10, SEQ ID NO:11, SEQ ID NO:12-14, SEQ ID NO:43-46, SEQ ID NO:34-41, SEQ ID NO:48-51 and SEQ ID NO:65, and most preferably wherein targeted delivery is performed in a subject; (v) A method for stimulating an immune response to an antigen, preferably the antigen is an antigen according to any one of the preceding paragraphs, more preferably the antigen comprises influenza hemagglutinin, porcine influenza hemagglutinin, ovalbumin (OVA), a spike protein, such as a porcine epidemic diarrhea virus spike protein, a spike protein of a human pathogenic coronavirus, such as a MERS-CoV spike protein, a SARS-CoV-2 spike protein, or a SARS-CoV-1 spike protein, a soluble portion of a B16 peptide or an MC38 peptide, and most preferably the antigen is selected from the group consisting of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:7, SEQ ID NO:8, SEQ ID NO:9, SEQ ID NO:10, SEQ ID NO:11, SEQ ID NO:12-14, SEQ ID NO:43-46, SEQ ID NO:34-41, SEQ ID NO:42-43, SEQ ID NO:44-45, SEQ ID NO:46-47, SEQ ID NO:48-49, SEQ ID NO:50-51, SEQ ID NO:52-53, SEQ ID NO:54-55, SEQ ID NO:56-57, SEQ ID NO:58-59, SEQ ID NO:59-60, SEQ ID NO:61-62, SEQ ID NO:63-64, SEQ ID NO:64-65, SEQ ID NO:65-66, SEQ ID NO:66-67, SEQ ID NO:67-70, SEQ ID NO:68-81, SEQ ID NO:69-90, SEQ ID NO:71-91, SEQ ID NO:72-92, SEQ ID NO:73-93, SEQ ID NO:74-9 a polypeptide sequence that is at least 60% or more (e.g., at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100%) identical to a polypeptide sequence selected from the group consisting of SEQ ID NOs: 48-51, and 65, and most preferably for use in stimulating an immune response to said antigen in a subject; (vi) CD8 (+) A method for triggering cross-protection induced by a T cell-mediated immune response, preferably a CD8 (+)A method for triggering cross-protection induced by a T cell mediated immune response, further preferably the antigen comprises a soluble portion of influenza hemagglutinin, swine influenza hemagglutinin, ovalbumin (OVA), a spike protein, such as porcine epidemic diarrhea virus spike protein, a spike protein of a human pathogenic coronavirus, such as MERS-CoV spike protein, SARS-CoV-2 spike protein, or SARS-CoV-1 spike protein, B16 peptide or MC38 peptide, most preferably the antigen is selected from the group consisting of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:7, SEQ ID NO:8, SEQ ID NO:9, SEQ ID NO:10, SEQ ID NO:11, SEQ ID NO:12-14, SEQ ID NO:43-46, SEQ ID NO:34-41, SEQ ID NO:42-43, SEQ ID NO:44-45, SEQ ID NO:46-47, SEQ ID NO:48-49, SEQ ID NO:50-51, SEQ ID NO:52-53, SEQ ID NO:54-55, SEQ ID NO:56-57, SEQ ID NO:58-59, SEQ ID NO:59-60, SEQ ID NO:61-62, SEQ ID NO:63-64, SEQ ID NO:64-65, SEQ ID NO:65-66, SEQ ID NO:66-70, SEQ ID NO:67-71, SEQ ID NO:68-82, SEQ ID NO:69-90, SEQ ID NO:71-92, SEQ ID NO:73-74, SEQ ID NO:75-76, SEQ ID NO:77-83, SEQ ID NO:78-84, SEQ ID NO:79- a polypeptide sequence selected from the group consisting of SEQ ID NOs:48-51, and SEQ ID NOs:49-52, which is at least 60% or more (e.g., at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100%) identical to a polypeptide sequence selected from the group consisting of SEQ ID NOs:48-51, and SEQ ID NOs:65, (vii) A method for delivering a peptide and / or protein to an antigen presenting cell (APC) according to any one of the preceding paragraphs, preferably the peptide and / or protein is an antigen according to any one of the preceding paragraphs, more preferably the antigen comprises influenza hemagglutinin, porcine influenza hemagglutinin, ovalbumin (OVA), a spike protein, such as porcine epidemic diarrhea virus spike protein, a spike protein of a human pathogenic coronavirus, such as MERS-CoV spike protein, SARS-CoV-2 spike protein, or SARS-CoV-1 spike protein, a soluble portion of a B16 peptide or an MC38 peptide, most preferably the antigen is selected from the group consisting of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:7, SEQ ID NO:8, SEQ ID NO:9, SEQ ID NO:10, SEQ ID NO:11, SEQ ID NO:12-14, SEQ ID NO:13-15, SEQ ID NO:14-16, SEQ ID NO:15-17, SEQ ID NO:16-18, SEQ ID NO:17-19, SEQ ID NO:18-20, SEQ ID NO:19-21, SEQ ID NO:22-23, SEQ ID NO:23-24, SEQ ID NO:24-25, SEQ ID NO:25-26, SEQ ID NO:26-27, SEQ ID NO:27-28, SEQ ID NO:28-29, SEQ ID NO:30-31, SEQ ID NO:31-32, SEQ ID NO:32-33, SEQ ID NO:33-34, SEQ ID NO:34-35, SEQ ID NO:35-36, SEQ ID NO:36-37, SEQ ID NO:37-38, SEQ ID NO a polypeptide sequence selected from the group consisting of SEQ ID NOs:43-46, SEQ ID NOs:34-41, SEQ ID NOs:48-51, and SEQ ID NO:65, which is at least 60% or more (e.g., at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100%) identical to a polypeptide sequence selected from the group consisting of SEQ ID NOs:43-46, SEQ ID NOs:34-41, SEQ ID NOs:48-51, and SEQ ID NO:65; (viii) CD8 (+) T cell-mediated immune response and / or CD4 (+)A method for triggering an immune response, including a T cell mediated immune response, preferably wherein the response is a response to an antigen according to any one of the preceding items, more preferably wherein the antigen comprises influenza hemagglutinin, swine influenza hemagglutinin, ovalbumin (OVA), a spike protein, such as a porcine epidemic diarrhea virus spike protein, a spike protein of a human pathogenic coronavirus, such as a MERS-CoV spike protein, a SARS-CoV-2 spike protein, or a SARS-CoV-1 spike protein, a soluble portion of a B16 peptide or a MC38 peptide, more preferably wherein the response is a response to an antigen according to any one of the preceding items, more preferably wherein the antigen comprises a soluble portion of a peptide selected from the group consisting of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:7, SEQ ID NO:8, SEQ ID NO:9, SEQ ID NO:10, SEQ ID NO:11, SEQ ID NO:12-14, SEQ ID NO:43-46, SEQ ID NO:47-48, SEQ ID NO:49-50, SEQ ID NO:51-52, SEQ ID NO:53-54, SEQ ID NO:55-56, SEQ ID NO:57-58, SEQ ID NO:59-60, SEQ ID NO:61-62, SEQ ID NO:63-64, SEQ ID NO:64-65, SEQ ID NO:65-66, SEQ ID NO:66-67, SEQ ID NO:67-68, SEQ ID NO:68-70, SEQ ID NO:69-81, SEQ ID NO:71-82, SEQ ID NO:72-83, SEQ ID NO:73-84, SEQ ID NO:74-85, SEQ ID NO:75-86, a method in which the method is in response to an antigen that is at least 60% or more (e.g., at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100%) identical to a polypeptide sequence selected from the group consisting of SEQ ID NOs:34-41, SEQ ID NOs:48-51, and SEQ ID NO:65; (ix) A method for treating, ameliorating, preventing or diagnosing an infectious disease, preferably wherein the infectious disease is a viral infectious disease or a bacterial infectious disease, more preferably wherein the viral infectious disease is selected from the group consisting of influenza infection, respiratory syncytial virus infection and herpes virus infection; (x) a method for treating, ameliorating, preventing or diagnosing cancer or an autoimmune disease; (xi) A method for sensitizing cancer cells to chemotherapy. (xii) a method for inducing apoptosis in cancer cells; (xiii) a method for stimulating an immune response in a subject; (xiv) methods for immunizing non-human animals; (xv) methods for preparing hybridomas; (xvi) the method according to any one of the preceding paragraphs, (xvii) The method according to any one of (i) to (xvi), which is an in vivo and / or ex vivo and / or in vitro method; (xviii) The method according to any one of (i) to (xvii) above, wherein the antigen is heterologous to the environment in which the antigen is used. 76. Use of the polymersome, composition, antigen-presenting cell, hybridoma or vaccine according to any one of the preceding items for one or more of the following: (i) to discover and / or screen and / or prepare antibodies; (ii) to discover and / or screen and / or prepare vaccines; (iii) to produce or prepare an immunogenic or immunostimulatory composition; (iv) for targeted delivery of proteins and / or peptides, preferably targeted delivery of antigenic proteins and / or peptides, more preferably targeted delivery is performed in a subject; (v) for stimulating an immune response to an antigen, preferably for use in stimulating an immune response to an antigen in a subject; (vi) CD8 (+) To trigger cross-protection induced by T cell-mediated immune responses, (vii) for delivery of a peptide or protein to an antigen presenting cell (APC), preferably the peptide or protein is an antigen, more preferably the peptide or protein is immunogenic or immunotherapeutic; (viii) CD8 (+) T cell-mediated immune response and / or CD4 (+) To trigger immune responses, including T cell-mediated immune responses, (ix) A method for treating, ameliorating, preventing or diagnosing an infectious disease, preferably the infectious disease is a viral infectious disease or a bacterial infectious disease, more preferably the viral infectious disease is selected from the group consisting of influenza infection, respiratory syncytial virus infection and herpes virus infection, comprising: (x) To treat, ameliorate, prevent or diagnose cancer or an autoimmune disease; (xi) To sensitize cancer cells to chemotherapy; (xii) for induction of apoptosis in cancer cells; (xiii) stimulating an immune response in a subject; (xiv) for immunizing non-human animals, (xv) for the preparation of hybridomas, (xvi) In the method according to any one of the preceding paragraphs, (xvii) For the use according to any one of (i) to (xvi), which is for in vivo and / or ex vivo and / or in vitro use, (xviii) For the use according to any one of (i) to (xvii) above, wherein the antigen is heterologous to the environment in which the antigen is used. 77. A method for inducing an immune response in a subject, comprising administering to the subject a polymersome formed from PDMS-PEO carrying an antigen. 78. The method according to item 77, wherein the antigen is encapsulated within a PDMS-PEO polymersome. 79. The method according to item 78, wherein the antigen encapsulated in the PDMS-PEO polymersome is a soluble antigen. 80. The method according to item 79, wherein the antigen is selected from the group consisting of polypeptides, carbohydrates, polynucleotides and combinations thereof. 81. The method according to item 77, wherein the antigen is incorporated into the surrounding membrane of the PDMS-PEO polymersome. 82. Antigen-loaded PDMS-PEO polymersomes. 83. The polymersome according to item 82, wherein the antigen is encapsulated within the PDMS-PEO polymersome. 84. The polymersome according to item 83, wherein the antigen encapsulated in the PDMS-PEO polymersome is a soluble antigen. 85. The polymersome according to item 84, wherein the antigen is selected from the group consisting of polypeptides, carbohydrates, polynucleotides and combinations thereof. 86. The polymersome according to item 85, wherein the antigen is incorporated into the surrounding membrane of the PDMS-PEO polymersome. 87. The polymersome according to item 86, wherein the antigen is a membrane-bound protein or a lipid antigen. 88. The polymersome according to item 87, wherein the membrane-bound protein is selected from the group consisting of transmembrane proteins, G protein-coupled receptors, neurotransmitter receptors, kinases, porins, ABC transporters, ion transporters, acetylcholine receptors and cell adhesion receptors. 89. A pharmaceutical composition comprising a polymersome according to any one of items 82 to 88. 90. Use of PDMS-PEO according to any one of items 82 to 88 or the pharmaceutical composition according to item 89 in vitro and in vivo for inducing an immune response. 91. To induce an immune response: (i) a polypeptide, (ii) carbohydrates, (iii) a polynucleotide, which is preferably not an antisense oligonucleotide, and more preferably is a DNA molecule or an mRNA molecule, or (iv) a combination of (i) and / or (ii) and / or (iii) 51. Use of a polymersome having a diameter of about 120 nm or more, preferably a polymersome according to any one of items 1 to 50, comprising a soluble encapsulated antigen selected from the group consisting of: 92. The use according to item 91, wherein the diameter of the polymersome is in the range of about 120 nm to about 1 μm, or about 140 nm to about 750 nm, or about 120 nm to about 500 nm, or about 140 nm to about 250 nm, about 120 nm to about 240 nm, about 150 nm to about 235 nm, about 170 nm to about 230 nm, or about 220 nm to about 180 nm, or about 190 nm to about 210 nm. 93. To induce an immune response: (i) a polypeptide, (ii) carbohydrates, (iii) a polynucleotide, which is preferably not an antisense oligonucleotide, and more preferably is a DNA molecule or an mRNA molecule, or (iv) a combination of (i) and / or (ii) and / or (iii) 51. Use of an ensemble of polymersomes having an average diameter of about 120 nm or more, preferably an ensemble of polymersomes as defined in any one of items 1 to 50, comprising a soluble encapsulated antigen selected from the group consisting of: 94. The use according to item 93, wherein the average diameter of the polymersome aggregates is in the range of about 120 nm to about 1 μm, or about 120 nm to about 750 nm, or about 120 nm to about 500 nm, or about 120 nm to about 250 nm, about 120 nm to about 240 nm, about 150 nm to about 235 nm, about 170 nm to about 230 nm, or about 220 nm to about 180 nm, or about 190 nm to about 210 nm. 95. The use of any one of items 91 to 94, wherein the subject is vaccinated against a viral infection. 96. The use according to any one of items 91 to 95, wherein the polymersome or polymersome aggregate is administered by a route of administration selected from the group consisting of oral administration, intranasal administration, administration to a mucosal surface, inhalation, intradermal administration, intraperitoneal administration, subcutaneous administration, intravenous administration and intramuscular administration. 97. The use according to any one of items 91 to 96, wherein the subject is a mammal, including a human, or a non-mammal. 98. The use according to item 97, wherein the subject is a mammalian animal and is to be vaccinated against a disease selected from the group consisting of cancer, viral infections and bacterial infections. 99. The use according to item 98, wherein the subject is a human and is to be vaccinated against a coronavirus infection. 100. The use according to item 99, wherein the coronavirus is pathogenic to humans. 101. The use according to item 99 or 100, wherein the coronavirus is a beta-coronavirus. 102. The use according to any one of items 99 to 101, wherein the coronavirus is a sarbecovirus or a merbecovirus. 103. 20. The use according to item 99, wherein the coronavirus is MERS-CoV, SARS-CoV-2 or SARS-CoV-1. 104. The use according to item 97, wherein the subject is a non-mammalian animal and is to be vaccinated against a disease selected from the group consisting of viral infections and bacterial infections. 105. The use according to item 104, wherein the non-mammalian animal is a bird (e.g. a poultry animal such as a chicken, duck, goose or turkey), a fish or a crustacean. 106. The use according to item 105, wherein the bird is a chicken, duck, goose or turkey. 107. The use according to item 105, wherein the fish is salmon, trout or tilapia. 108. The use according to item 105, wherein the crustacean is a shrimp, a prawn, or a crab. 109. The use according to item 97, wherein the mammal is a goat, sheep, cow, or pig. 110. The use according to item 109, wherein the animal is a pig and is vaccinated against porcine epidemic diarrhea virus. 111. The use according to item 109, wherein the animal is an ungulate and is vaccinated against foot and mouth disease virus.

[0233] The present invention is also characterized in the following aspects. 1. A method of inducing an immune response in a subject by administration of an antigen and an adjuvant, wherein the antigen is associated with a first population of polymersomes and the adjuvant is associated with a second population of polymersomes, and the two populations of polymersomes are administered to the subject. 2. The method of embodiment 1, wherein the antigen is associated with the first population of polymersomes by encapsulation of the antigen within the first population of polymersomes, by incorporation of the antigen into the surrounding membrane of the polymersomes of the first population of polymersomes, by conjugation of the antigen to the outer surface of the polymersomes by covalent bonds, and / or by conjugation of the antigen to the outer surface of the polymersomes by non-covalent bonds. 3. The method of embodiment 1 or embodiment 2, wherein the adjuvant is associated with the second population of polymersomes by encapsulation of the adjuvant within the second population of polymersomes, by incorporation of the adjuvant into the surrounding membrane of the polymersomes of the second population of polymersomes, by conjugation of the adjuvant to the outer surface of the polymersomes by covalent bonds, and / or by conjugation of the adjuvant to the outer surface of the polymersomes by non-covalent bonds. 4. The method of embodiment 2 or embodiment 3, wherein a first population of polymersomes has an antigen encapsulated within the polymersomes and a second population of polymersomes has an adjuvant encapsulated within the polymersomes. 5. The method of embodiment 2 or embodiment 3, wherein a first population of polymersomes has an antigen covalently or non-covalently conjugated to the outer surface of the polymersomes, and a second population of polymersomes has an adjuvant covalently or non-covalently conjugated to the outer surface of the polymersomes. 6. The method of embodiment 2 or embodiment 3, wherein a first population of polymersomes has an antigen incorporated in the surrounding membrane of the polymersomes and a second population of polymersomes has an adjuvant incorporated in the surrounding membrane of the polymer. 7. The method of embodiment 2 or embodiment 3, wherein a first population of polymersomes has an antigen encapsulated within the polymersomes and a second population of polymersomes has an adjuvant covalently conjugated to the outer surface of the polymersomes. 8. The method of embodiment 2 or embodiment 3, wherein a first population of polymersomes has an antigen covalently conjugated to the outer surface of the polymersomes, and a second population of polymersomes has an adjuvant encapsulated within the polymersomes. 9. The method of any one of the preceding embodiments, wherein the first population of polymersomes and the second population of polymersomes are administered simultaneously (at the same time) or at different times. 10. The method of embodiment 9, wherein the step of simultaneously administering the first population of polymersomes and the second population of polymersomes comprises administering the two polymersome populations together (co-administration) or administering each of the two polymersome populations separately. 11. The method of any one of the preceding embodiments, wherein the two polymersome populations are prepared separately. 12. The method of embodiment 11, wherein the two polymersome populations are mixed together prior to administration. 13. The method of any one of embodiments 1-12, wherein the two polymersome populations are administered by a route of administration selected from the group consisting of oral administration, intranasal administration, administration to a mucosal surface, inhalation, intradermal administration, intraperitoneal administration, subcutaneous administration, intravenous administration, and intramuscular administration. 14. The method of any one of the preceding embodiments, wherein the subject is a mammal, including a human, or a non-mammal. 15. The method of embodiment 14, wherein the subject is a mammal and is vaccinated against a disease selected from the group consisting of cancer, viral infection and bacterial infection. 16. The method of embodiment 15, wherein the subject is a human and is vaccinated against a coronavirus infection. 17. The method of embodiment 16, wherein the coronavirus is pathogenic to humans. 18. The method of embodiment 16 or embodiment 17, wherein the coronavirus is a betacoronavirus. 19. The method of any one of embodiments 16 to 18, wherein the coronavirus is a sarbecovirus or a merbecovirus. 20. The method of embodiment 19, wherein the coronavirus is MERS-CoV, SARS-CoV-2 or SARS-CoV-1. 21. The method of embodiment 14, wherein the subject is a non-mammalian animal and is vaccinated against a disease selected from the group consisting of viral infections and bacterial infections. 22. The method of embodiment 21, wherein the non-mammalian animal is a bird (e.g., a poultry such as a chicken, duck, goose, or turkey), a fish, or a crustacean. 23. The method of embodiment 21, wherein the bird is a chicken, duck, goose or turkey. 24. The method of embodiment 21, wherein the fish is salmon, trout or tilapia. 25. The method of embodiment 1621, wherein the crustacean is a shrimp, prawn, or crab. 26. The method of embodiment 14, wherein the mammal is a goat, sheep, cow, or pig. 27. The method of embodiment 26, wherein the animal is a pig and is vaccinated against porcine epidemic diarrhea virus. 28. The method of embodiment 26, wherein the animal is an ungulate and is vaccinated against foot and mouth disease virus. 29. The method of any one of the previous embodiments, wherein the encapsulated antigen is a soluble or solubilized antigen. 30. The antigen, preferably a soluble or solubilized encapsulated antigen, (i) a polypeptide, (ii) carbohydrates, (iii) a polynucleotide which is not an antisense oligonucleotide and is preferably a DNA molecule or an mRNA molecule; (iv) a combination of (i) and / or (ii) and / or (iii) The method of any one of the preceding aspects, wherein the method is selected from the group consisting of: 31. The method of embodiment 14, wherein the first and / or second population of polymersomes are oxidation-stable polymersomes comprising a soluble encapsulated antigen or adjuvant, or the first and / or second population of polymersomes are oxidation-sensitive polymersomes comprising a soluble encapsulated antigen or adjuvant. 32. An amide moiety, and / or (ii) a secondary amine moiety, and / or (iii) a 1,2,3-triazole moiety, which is preferably a 1,4-disubstituted[1,2,3]triazole moiety or a 1,5-disubstituted[1,2,3]triazole moiety, and / or (iv) a pyrazoline moiety, and / or (vi) an ester moiety, and / or (vii) a carbamate moiety and / or a carbonate moiety, according to any one of the previous embodiments. 33. The method of embodiment 32, wherein the covalent bonds conjugating the antigen or adjuvant to the outer surface of the first polymersome population and / or the second polymersome population are formed by reacting reactive groups present on the outer surface of the polymersome with reactive groups on the antigen or adjuvant. 34. The method of embodiment 33, wherein the covalent bond is selected from the group consisting of: (i) a carboxamide bond, (ii) a 1,4-disubstituted[1,2,3]triazole or 1,5-disubstituted[1,2,3]triazole bond, and (iii) a substituted pyrazoline bond. 35. The method of embodiment 34, wherein (i) the reactive groups present on the outer surface of the polymersome are aldehyde groups and the reactive groups on the antigen or adjuvant are amine groups, thereby forming a carboxamide group, or (ii) the reactive groups present on the outer surface of the polymersome are alkyne groups and the reactive groups on the antigen or adjuvant are azide groups, thereby forming a 1,2,3-triazole group, more preferably a 1,4-disubstituted or 1,5-disubstituted 1,2,3-triazole, preferably by copper or ruthenium catalyzed azide-alkyne cycloaddition, or (iii) the reactive groups present on the outer surface of the polymersome are methacrylate and / or hydroxyl groups and the reactive groups on the antigen or adjuvant are tetrazole groups, thereby forming a pyrazoline group, preferably the formation of the pyrazoline group comprises a nitrilimine intermediate. 36. The method of embodiment 35, wherein the carboxamide bond is further reacted with a reducing agent to form a secondary amine. 37. The method of any one of embodiments 32-36, wherein the covalent bond is formed by a linker moiety. 38. The method of embodiment 37, wherein the linker moiety L is a peptide linker or a straight-chain or branched-chain hydrocarbon-based linker. 39. The method of embodiment 37 or embodiment 38, wherein the linker moiety comprises 1 to about 550 main chain atoms, 1 to about 500 main chain atoms, 1 to about 450 main chain atoms, 1 to about 350 main chain atoms, 1 to about 300 main chain atoms, 1 to about 250 main chain atoms, 1 to about 200 main chain atoms, 1 to about 150 main chain atoms, 1 to about 100 main chain atoms, 1 to about 50 main chain atoms, 1 to about 30 main chain atoms, 1 to about 20 main chain atoms, 1 to about 15 main chain atoms, or 1 to about 12 main chain atoms, or 1 to about 10 main chain atoms, wherein a main chain atom is a carbon atom optionally replaced with one or more heteroatoms selected from the group consisting of N, O, P, and S. 40. The method of any one of embodiments 37 to 39, wherein the linker moiety comprises a membrane anchor domain that incorporates the linker moiety into the membrane of the polymersome. 41. The method of embodiment 40, wherein the membrane anchor domain comprises a lipid. 42. The method of embodiment 41, wherein the lipid is a phospholipid or a glycolipid. 43. The method of embodiment 42, wherein the glycolipid comprises glycophosphatidylinositol (GPI). 44. The method of embodiment 42, wherein the phospholipid is a sphingophospholipid or a glycerophospholipid. 45. The method of embodiment 44, wherein the sphingophospholipid comprises distearoylphosphatidylethanolamine [DSPE] conjugated to polyethylene glycol (PEG) (DSPE-PEG) or a cholesterol-based conjugate. 46. ​​The method of embodiment 45, wherein the DSPE-PEG contains from 2 to about 500 ethylene oxide units. 47. The method of any one of embodiments 32 to 46, wherein the linker is non-hydrolyzable and / or non-oxidizable under physiological conditions. 48. A method according to any one of aspects 2 to 47, wherein the antigen incorporated into the surrounding membrane of the polymersome is a membrane-bound protein or lipid antigen. 49. The method of embodiment 48, wherein the membrane-bound protein comprises an extracellular fragment or extracellular domain of a transmembrane protein. 50. The method of embodiment 48 or embodiment 49, wherein the membrane-bound protein is a transmembrane protein, a G protein-coupled receptor, a neurotransmitter receptor, a kinase, a porin, an ABC transporter, an ion transporter, an acetylcholine receptor, or a cell adhesion receptor. 51. The method of any one of embodiments 48 to 50, wherein the lipid antigen is a synthetic lipid or a naturally occurring lipid. 52. The method of any one of embodiments 2 to 51, wherein the non-covalent bond for conjugating the antigen and / or adjuvant to the outer surface of the polymersomes of the first polymersome population and / or the second polymersome population comprises a binding pair selected from the group consisting of streptavidin and biotin, avidin and biotin, streptavidin and streptavidin binding peptide, and avidin and avidin binding peptide, or is an electrostatic interaction. 53. The method of any one of embodiments 1 to 52, wherein the first population of polymersomes and the second population of polymersomes comprise or are formed from the same at least one amphiphilic polymer. 54. The method of any one of embodiments 1 to 52, wherein the first population of polymersomes and the second population of polymersomes comprise or are formed from at least one different amphiphilic polymer. 55. The method of any one of the preceding embodiments, wherein the first and / or second population of polymersomes are oxidatively stable. 56. Administration of the first and / or second population of polymersomes inhibits CD8 (+) The method according to any one of the previous aspects, having the ability to induce a T cell mediated immune response, preferably said induction being in vivo, ex vivo or in vitro induction. 57. The encapsulated antigen comprises a soluble portion of a membrane protein (MP) or a membrane-associated peptide (MAP), preferably the antigen comprises a soluble portion of influenza hemagglutinin, swine influenza hemagglutinin, a spike protein, such as porcine epidemic diarrhea virus spike protein, a spike protein of a human pathogenic coronavirus, such as MERS-CoV spike protein, SARS-CoV-2 spike protein, or SARS-CoV-1 spike protein, ovalbumin (OVA), a B16 peptide or an MC38 peptide, more preferably the antigen comprises a soluble portion of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:7, SEQ ID NO:8, SEQ ID NO:9, SEQ ID NO:10, SEQ ID NO:11, SEQ ID NO:12, SEQ ID NO:13, SEQ ID NO:14, SEQ ID NO:15, SEQ ID NO:16, SEQ ID NO:17, SEQ ID NO:18, SEQ ID NO:19, SEQ ID NO:20, SEQ ID NO:21, SEQ ID NO:22, SEQ ID NO:23, SEQ ID NO:24, SEQ ID NO:25, SEQ ID NO:26, SEQ ID NO:27, SEQ ID NO:28, SEQ ID NO:29, SEQ ID NO:30, SEQ ID NO:31, SEQ ID NO:32, SEQ ID NO:33, SEQ ID NO:34, SEQ ID NO:35, SEQ ID NO:36, SEQ ID NO:37, SEQ ID NO:38, SEQ ID NO:39, SEQ ID NO:40, SEQ ID NO:41, SEQ ID NO:42, SEQ ID NO:43, SEQ ID NO:44, SEQ ID NO:45, SEQ ID NO:46, SEQ The method of any one of the preceding embodiments, comprising a polypeptide that is at least 60% or more (e.g., at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100%) identical to a polypeptide sequence selected from the group consisting of SEQ ID NOs:43-46, SEQ ID NOs:34-41, SEQ ID NOs:48-51, and SEQ ID NO:65. 58. The method of any one of the preceding embodiments, wherein the encapsulated antigen comprises a fragment of a viral spike protein, wherein the fragment comprises, consists essentially of, or consists of the S1 portion of the spike protein, the S2 portion of the spike protein, a combination of the S1 and S2 portions of the spike protein, the receptor binding domain (RBD) of the spike protein, or a combination thereof. 59. A method according to any one of the preceding embodiments, wherein the first and / or second population of polymersomes are oxidatively stable in the presence of serum components, preferably the oxidative stability is in vivo, ex vivo or in vitro oxidative stability. 60. The method of any one of the preceding embodiments, wherein the first and / or second population of polymersomes are stable within endosomes, preferably said stability being in vivo, ex vivo or in vitro stable. 61. The method of any one of the preceding embodiments, wherein the first and / or second population of polymersomes have improved oxidative stability compared to the oxidative stability of the corresponding liposomes, preferably the improved stability being in vivo, ex vivo or in vitro. 62. The first and / or second population of polymersomes release their contents, including soluble encapsulated antigens, in an oxidation-independent manner to target CD8 (+) The method according to any one of the preceding aspects, having the ability to trigger a T cell mediated immune response, preferably said release being in vivo, ex vivo or in vitro release. 63. The first and / or second population of polymersomes are (+) The method according to any one of the preceding aspects, having the ability to elicit a cellular immune response, including a T cell mediated immune response, preferably wherein said immune response is an in vivo, ex vivo or in vitro immune response. 64. The first and / or second population polymersomes are capable of binding to CD8 (+) The method of any one of the preceding aspects, having the ability to elicit a cellular and / or humoral immune response, including a T cell mediated immune response, preferably wherein the immune response is an in vivo, ex vivo or in vitro immune response. 65. The method of embodiment 64, wherein the humoral immune response comprises the production of specific antibodies, and more preferably, the immune response is an in vivo, ex vivo or in vitro immune response. 66. The first and / or second population of polymersomes are effector CD4 (+) The method according to any one of the preceding aspects, having the ability to enhance the frequency of T cells, preferably said enhancement being in vivo, ex vivo or in vitro enhancement. 67. The method of embodiment 64, wherein the cellular immune response comprises a T cell-mediated immune response, preferably wherein the immune response is an in vivo, ex vivo or in vitro immune response. 68. The first and / or second population of polymersomes are capable of inhibiting antigen-specific CD8+ binding compared to free antigen. (+) The method of any one of the preceding aspects, having the ability to enhance clonal expansion of T cells, preferably wherein said expansion is in vivo, ex vivo or in vitro expansion. 69. The first and / or second population of polymersomes are capable of binding antigen-specific effector CD8 (+) The method according to any one of the preceding aspects, having the ability to induce T cells, preferably said induction being in vivo, ex vivo or in vitro induction. 70. The first and / or second population of polymersomes are capable of binding to antigen-specific CD8 (+) The method according to any one of the preceding aspects, having the ability to enhance the cytotoxic phenotype of T cells, preferably said enhancement being in vivo, ex vivo or in vitro enhancement. 71. The method of any one of the preceding embodiments, wherein the first and / or second population of polymersomes are capable of targeting lymph node resident macrophages and / or B cells, preferably wherein the targeting is in vivo, ex vivo or in vitro targeting. 72. The method of any one of the preceding embodiments, wherein the first and / or second population of polymersomes are reduction-stable, preferably the first and / or second population of polymersomes are reduction-stable in the presence of serum components, and more preferably the reduction-stability is in vivo, ex vivo or in vitro reduction-stable. 73. The method of any one of the preceding embodiments, wherein the first and / or second population of polymersomes have reduced permeability, preferably the reduced permeability is compared to the permeability of the corresponding liposomes, and more preferably the permeability is in vivo, ex vivo or in vitro permeability. 74. The method of any one of the preceding embodiments, wherein the first and / or second population of polymersomes are capable of releasing their contents within an endosome, preferably the endosome is a late endosome, and more preferably the release is in vivo, ex vivo or in vitro release. 75. The method of any one of the preceding embodiments, wherein the first and / or second population of polymersomes have one or more of the following capabilities: (i) the ability to induce a cellular immune response; preferably the cellular immune response is a CD8 (+) More preferably, the cellular immune response comprises a CD8 (+) Preferably, the cellular immune response is a T cell mediated immune response, most preferably the cellular immune response is a cellular immune response against influenza hemagglutinin, swine influenza hemagglutinin, a spike protein, such as a porcine epidemic diarrhea virus spike protein, a spike protein of a human pathogenic coronavirus, such as a MERS-CoV spike protein, a SARS-CoV-2 spike protein, or a SARS-CoV-1 spike protein, ovalbumin (OVA), a soluble portion of a B16 peptide or an MC38 peptide, and most preferably the cellular immune response is against a soluble portion of a peptide, such as ... a cellular immune response to a polypeptide that is at least 60% or more (e.g., at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100%) identical to a polypeptide sequence selected from the group consisting of SEQ ID NO:48-51, and SEQ ID NO:65; (ii) the ability to release the contents of the polymersome within an endosome; preferably the endosome is a late endosome, more preferably the contents comprises influenza hemagglutinin, swine influenza hemagglutinin, a spike protein, such as a porcine epidemic diarrhea virus spike protein, a spike protein of a human pathogenic coronavirus, such as a MERS-CoV spike protein, a SARS-CoV-2 spike protein, or a SARS-CoV-1 spike protein, an ovalbumin (OVA), a soluble portion of a B16 peptide or an MC38 peptide, most preferably the contents comprises a soluble portion of a peptide selected from the group consisting of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:7, SEQ ID NO:8, SEQ ID NO:9, SEQ ID NO:10, SEQ ID NO:11, SEQ ID NOs:12-14, SEQ ID NOs:43-46, SEQ ID NOs:47-48, SEQ ID NOs:49-50, SEQ ID NOs:51-52, SEQ ID NOs:53-54, SEQ ID NOs:55-56, SEQ ID NOs:57-58, SEQ ID NOs:59-60, SEQ ID NOs:61-62, SEQ ID NOs:63-64, SEQ ID NOs:64-65, SEQ ID NOs:65-66, SEQ ID NOs:66-67, SEQ ID NOs:67-68, SEQ ID NOs:68-69, SEQ ID NOs:70-72, SEQ ID NOs:73-74, SEQ ID NOs:75-76, SEQ ID NOs:77-78, SEQ ID NOs:79-80, SEQ ID NOs:82-84, SEQ ID NOs:83 SEQ ID NOs:34-41, SEQ ID NOs:48-51, and SEQ ID NO:65; (iii) Release of polymersome contents in an oxidation-independent manner to CD8 (+)the ability to trigger a T cell mediated immune response; preferably the content comprises a soluble portion of influenza hemagglutinin, swine influenza hemagglutinin, a spike protein, such as a porcine epidemic diarrhea virus spike protein, a spike protein of a human pathogenic coronavirus, such as a MERS-CoV spike protein, a SARS-CoV-2 spike protein, or a SARS-CoV-1 spike protein, an ovalbumin (OVA), a B16 peptide or an MC38 peptide, more preferably the content comprises a soluble portion of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:7, SEQ ID NO:8, SEQ ID NO:9, SEQ ID NO:10, SEQ ID NO:11, SEQ ID NO:12-14, SEQ ID NO:43-46, SEQ ID NO:34-41, SEQ ID NO:48-51, and SEQ ID NO:53-54. a polypeptide that is at least 60% or more (e.g., at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100%) identical to a polypeptide sequence selected from the group consisting of ID NO:65; (iv) the ability to stimulate an immune response against said antigen; preferably said antigen comprises a soluble portion of influenza hemagglutinin, swine influenza hemagglutinin, a spike protein, such as a porcine epidemic diarrhea virus spike protein, a spike protein of a human pathogenic coronavirus, such as a MERS-CoV spike protein, a SARS-CoV-2 spike protein, or a SARS-CoV-1 spike protein, ovalbumin (OVA), a B16 peptide or an MC38 peptide, more preferably said antigen is selected from the group consisting of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:7, SEQ ID NO:8, SEQ ID NO:9, SEQ ID NO:10, SEQ ID NO:11, SEQ ID NO:12-14, SEQ ID NO:43-46, SEQ ID NO:34-41, SEQ ID NO:42-43, SEQ ID NO:44-45, SEQ ID NO:46-47, SEQ ID NO:48-49, SEQ ID NO:50-51, SEQ ID NO:52-53, SEQ ID NO:54-55, SEQ ID NO:56-57, SEQ ID NO:58-59, SEQ ID NO:59-60, SEQ ID NO:61-62, SEQ ID NO:63-64, SEQ ID NO:64-65, SEQ ID NO:65-66, SEQ ID NO:66-70, SEQ ID NO:67-71, SEQ ID NO:68-82, SEQ ID NO:69-90, SEQ ID NO:71-92, SEQ ID NO:73-74, SEQ ID NO:75-83, SEQ ID NO:76-84, SEQ ID NO:77-85, SEQ ID NO:78-9 SEQ ID NO:48-51, and SEQ ID NO:65; (v) CD8 (+)the ability to trigger cross-protection induced by a T cell-mediated immune response; preferably the response is a response to a soluble portion of influenza hemagglutinin, swine influenza hemagglutinin, spike protein, such as porcine epidemic diarrhea virus spike protein, ovalbumin (OVA), B16 peptide or MC38 peptide, more preferably the response is a response to a soluble portion of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:7, SEQ ID NO:8, SEQ ID NO:9, SEQ ID NO:10, SEQ ID NO:11, SEQ ID NO:12, 13 and 14, SEQ ID NO:43 to 46, SEQ ID NO:34 to 41, SEQ ID NO:48 to 51, and SEQ ID to a polypeptide that is at least 60% or more (e.g., at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100%) identical to a polypeptide sequence selected from the group consisting of NO:65; (vi) the ability to deliver a peptide or protein to an antigen presenting cell (APC); preferably the peptide or protein comprises or is derived from influenza hemagglutinin, swine influenza hemagglutinin, a spike protein, such as the porcine epidemic diarrhea virus spike protein, a spike protein of a human pathogenic coronavirus, such as the MERS-CoV spike protein, the SARS-CoV-2 spike protein, or the SARS-CoV-1 spike protein, an ovalbumin (OVA), a soluble portion of a B16 peptide or an MC38 peptide, more preferably the peptide or protein is selected from the group consisting of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:7, SEQ ID NO:8, SEQ ID NO:9, SEQ ID NO:10, SEQ ID NO:11, SEQ ID NO:12, 13 and 14, SEQ ID NO:43 to 46, SEQ ID NO:47 to 49, SEQ ID NO:51 to 52, SEQ ID NO:53 to 54, SEQ ID NO:55 to 56, SEQ ID NO:57 to 58, SEQ ID NO:59 to 60, SEQ ID NO:61 to 62, SEQ ID NO:63 to 64, SEQ ID NO:65 to 66, SEQ ID NO:66 to 67, SEQ ID NO:68 to 69, SEQ ID NO:69 to 70, SEQ ID NO:71 to 72, SEQ ID NO:73 to 74, SEQ ID NO:75 to 76, SEQ ID NO:76 to 77, SEQ ID NO:78 to 79, SEQ ID NO:79 to 80, SEQ ID NO:81 to 82, SEQ ID NO:83 to 84, SEQ ID NO:84 to 85 comprising or derived from a polypeptide that is at least 60% or more identical (e.g., at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100%) to a polypeptide sequence selected from the group consisting of SEQ ID NOs:34-41, SEQ ID NOs:48-51, and SEQ ID NO:65; (vii) CD8 (+) T cell-mediated immune response and / or CD4 (+)the ability to trigger an immune response, including a T cell mediated immune response; preferably the response is a response to a soluble portion of influenza hemagglutinin, swine influenza hemagglutinin, ovalbumin (OVA), a spike protein, such as a porcine epidemic diarrhea virus spike protein, a spike protein of a human pathogenic coronavirus, such as a MERS-CoV spike protein, a SARS-CoV-2 spike protein, or a SARS-CoV-1 spike protein, a B16 peptide or an MC38 peptide, more preferably the response is a response to a soluble portion of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:7, SEQ ID NO:8, SEQ ID NO:9, SEQ ID NO:10, SEQ ID NO:11, SEQ ID NO:12, 13 and 14, SEQ ID NOs:43 to 46, SEQ ID NOs:34 to 41, SEQ ID to a polypeptide that is at least 60% or more (e.g., at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100%) identical to a polypeptide sequence selected from the group consisting of SEQ ID NOs:48-51, and SEQ ID NO:65; (viii) the ability to stimulate an immune response in a subject; preferably the response is a response to influenza hemagglutinin, swine influenza hemagglutinin, a spike protein, such as a porcine epidemic diarrhea virus spike protein, a spike protein of a human pathogenic coronavirus, such as a MERS-CoV spike protein, a SARS-CoV-2 spike protein, or a SARS-CoV-1 spike protein, ovalbumin (OVA), a soluble portion of a B16 peptide or an MC38 peptide, more preferably the response is a response to a soluble portion of a peptide, such as ... to a polypeptide that is at least 60% or more (e.g., at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100%) identical to a polypeptide sequence selected from the group consisting of SEQ ID NOs:48-51, and SEQ ID NO:65; (ix) the ability to immunize a non-human animal; preferably the immunization is against influenza hemagglutinin, swine influenza hemagglutinin, a spike protein, such as a porcine epidemic diarrhea virus spike protein, a spike protein of a human pathogenic coronavirus, such as a MERS-CoV spike protein, a SARS-CoV-2 spike protein, or a SARS-CoV-1 spike protein, ovalbumin (OVA), a soluble portion of a B16 peptide or an MC38 peptide, more preferably the immunization is against a soluble portion of ... immunization against a polypeptide that is at least 60% or more (e.g., at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100%) identical to a polypeptide sequence selected from the group consisting of SEQ ID NOs:34-41, SEQ ID NOs:48-51, and SEQ ID NO:65; (x) the first population and / or the second population of polymersomes have an altered antigenicity compared to the corresponding antigenicity of the antigen without said polymersomes; preferably the antigen is influenza hemagglutinin, swine influenza hemagglutinin, a spike protein, such as porcine epidemic diarrhea virus spike protein, a spike protein of a human pathogenic coronavirus, such as MERS-CoV spike protein, SARS-CoV-2 spike protein, or SARS-CoV-1 spike protein, ovalbumin (OVA), a soluble portion of a B16 peptide or an MC38 peptide, more preferably the antigen is selected from the group consisting of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:7, SEQ ID NO:8, SEQ ID NO:9, SEQ ID NO:10, SEQ ID NO:11, SEQ ID NO:12, 13 and 14, SEQ ID NO:15, SEQ ID NO:16, SEQ ID NO:17, SEQ ID NO:19, SEQ ID NO:20, SEQ ID NO:21, SEQ ID NO:22, SEQ ID NO:23, SEQ ID NO:24, SEQ ID NO:25, SEQ ID NO:26, SEQ ID NO:27, SEQ ID NO:28, SEQ ID NO:29, SEQ ID NO:30, SEQ ID NO:31, SEQ ID NO:32, SEQ ID NO:33, SEQ ID NO:34, SEQ ID NO:35, SEQ ID NO:36, SEQ ID NO:37, SEQ ID NO:38, SEQ ID NO:39, SEQ ID NO:40, SEQ ID NO:41, SEQ ID NO:42, SEQ ID NO:43, SEQ ID NO:44, SEQ ID NO:45, SEQ ID NO:46, SEQ ID NO:47, SEQ a polypeptide that is at least 60% or more (e.g., at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100%) identical to a polypeptide sequence selected from the group consisting of SEQ ID NOs:43-46, SEQ ID NOs:34-41, SEQ ID NOs:48-51, and SEQ ID NO:65; (xi) the first and / or second population of polymersomes have altered immunogenicity compared to the corresponding immunogenicity of the antigen without the polymersome; preferably the immunogen is influenza hemagglutinin, swine influenza hemagglutinin, a spike protein, such as a porcine epidemic diarrhea virus spike protein, a spike protein of a human pathogenic coronavirus, such as a MERS-CoV spike protein, a SARS-CoV-2 spike protein, or a SARS-CoV-1 spike protein, ovalbumin (OVA), a soluble portion of a B16 peptide or an MC38 peptide, more preferably the immunogen is selected from the group consisting of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:7, SEQ ID NO:8, SEQ ID NO:9, SEQ ID NO:10, SEQ ID NO:11, SEQ ID NO:12, SEQ ID NO:13, SEQ ID NO:14, SEQ ID NO:15, SEQ ID NO:16, SEQ ID NO:17, SEQ ID NO:18, SEQ ID NO:19, SEQ ID NO:20, SEQ ID NO:21, SEQ ID NO:22, SEQ ID NO:23, SEQ ID NO:24, SEQ ID NO:25, SEQ ID NO:26, SEQ ID NO:27, SEQ ID NO:28, SEQ ID NO:29, SEQ ID NO:30, SEQ ID NO:31, SEQ ID NO:32, SEQ ID NO:33, SEQ ID NO:34, SEQ ID NO:35, SEQ ID NO:36, SEQ ID NO:37, SEQ ID NO:38, SEQ ID NO:39, SEQ ID NO:40, SEQ ID NO:41, SEQ ID NO:42, SEQ ID NO:43, SEQ ID NO:44, SEQ ID NO:45, and SEQ ID NO:65. 76. The method of any one of the preceding embodiments, wherein the first and / or second population of polymersomes have one or more of the following characteristics: (i) the first and / or second population of polymersomes comprises an oxidatively stable membrane; and / or (ii) the first and / or second population of polymersomes are synthetic; and / or (iii) the first and / or second population of polymersomes does not contain or is mixed with non-encapsulated antigen, and / or (iv) the first and / or second population of polymersomes comprises a membrane of an amphiphilic polymer; and / or (v) the first and / or second population of polymersomes comprises an amphiphilic synthetic block copolymer that forms a vesicle membrane; and / or (vi) the first and / or second population of polymersomes have a diameter of greater than 70 nm, preferably the diameter is in the range of about 100 nm to about 1 μm, or about 100 nm to about 750 nm, or about 100 nm to about 500 nm, or about 125 nm to about 250 nm, about 140 nm to about 240 nm, about 150 nm to about 235 nm, about 170 nm to about 230 nm, or about 220 nm to about 180 nm, or about 190 nm to about 210 nm, and most preferably the diameter is about 200 nm; and / or (vii) the first and / or second population of polymersomes have the morphology of vesicles; (viii) the first and / or second population of polymersomes are self-assembling. 77. The method of any one of the preceding embodiments, wherein the average diameter of the first and / or second population of polymersomes is in the range of about 100 nm to about 1 μm, or about 100 nm to about 750 nm, or about 100 nm to about 500 nm, or about 125 nm to about 250 nm, about 140 nm to about 240 nm, about 150 nm to about 235 nm, about 170 nm to about 230 nm, or about 220 nm to about 180 nm, or about 190 nm to about 210 nm. 78. The method of any one of the above aspects, wherein the antigen is an immunogen. 79. The method of any one of the previous embodiments, wherein the antigen is selected from the group consisting of (i) an autoantigen, (ii) a non-self antigen, (iii) a non-self immunogen, and (iv) an autoimmunogen. 80. The antigen is (i) a polypeptide that is at least 80% or more (e.g., at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100%) identical to a viral polypeptide sequence; preferably the viral polypeptide sequence is influenza hemagglutinin, porcine influenza hemagglutinin, porcine epidemic diarrhea virus spike protein, MERS-CoV spike protein, or SARS-CoV-2 spike protein, and more preferably the viral polypeptide sequence is selected from the group consisting of SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:7 and SEQ ID NO:8, SEQ ID NO:12, 13 and 14, SEQ ID NO:43-46, SEQ ID NO:34-41, SEQ ID NO:48-51, and SEQ ID NO:65; (ii) a polypeptide that is at least 80% or more identical (e.g., at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100%) to a bacterial polypeptide sequence; (iii) a polypeptide that is at least 80% or more (e.g., at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100%) identical to a mammalian or avian polypeptide sequence; preferably, the mammalian or avian polypeptide sequence is ovalbumin (OVA), B16 peptide or MC38 peptide, and more preferably, the mammalian or avian polypeptide sequence is selected from the group consisting of SEQ ID NO:4, SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:9, SEQ ID NO:10 and SEQ ID NO:11. The method of any one of the preceding aspects, wherein the method is selected from the group consisting of: 81. The method of any one of embodiments 3-80, wherein the mammalian antigen comprises a polypeptide sequence selected from the group consisting of human, rodent, lagomorph, and equine polypeptide sequences. 82. The method of any one of the previous embodiments, wherein the antigen is an antibody or a fragment thereof. 83. Antigen (i) influenza hemagglutinin (HA), preferably selected from the group consisting of SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:7 and SEQ ID NO:8; (ii) swine influenza hemagglutinin (HA), preferably SEQ ID NO:6; (iii) ovalbumin (OVA), preferably SEQ ID NO:4; (iv) B16 peptide, preferably selected from the group consisting of SEQ ID NO:9, SEQ ID NO:10 and SEQ ID NO:11; (v) MC38 peptides, preferably selected from the group consisting of SEQ ID NO:1, SEQ ID NO:2 and SEQ ID NO:3; (vi) B16 peptide and MC38 peptide, preferably the peptide is independently selected from the group: (i) SEQ ID NO: 1-3 and (ii) SEQ ID NO: 9-11; (vii) Porcine epidemic diarrhea virus spike protein and soluble fragments thereof, preferably fragments of SEQ ID NO: 12, 13 or 14. (viii) MERS-CoV spike protein and soluble fragments thereof, preferably any one of the spike proteins (fragments) of SEQ ID NOs: 42 to 46; (ix) SARS-CoV-2 spike protein and soluble fragments thereof, preferably the spike protein (fragment) of any one of SEQ ID NOs: 19-41 and SEQ ID NOs: 65-66; and (x) SARS-CoV-1 spike protein and soluble fragments thereof, preferably any one of the spike proteins (fragments) of SEQ ID NOs: 47 to 51. The method of any one of the preceding aspects, wherein the method is selected from the group consisting of: 84. The method of any one of the preceding embodiments, wherein the first and / or second population of polymersomes is selected from the group consisting of cationic polymersomes, anionic polymersomes, non-ionic polymersomes, and mixtures thereof. 85. The method of any one of the previous aspects, wherein the block copolymer or amphiphilic polymer is essentially non-immunogenic or essentially non-antigenic, preferably the block copolymer or amphiphilic polymer is non-immunogenic or non-antigenic. 86. The method of embodiment 85, wherein the block copolymer or amphiphilic polymer is not an immunostimulant or an adjuvant. 87. The method of any one of the preceding embodiments, wherein the first and / or second population of polymersomes comprises or is formed from an amphiphilic polymer that comprises or consists of a diblock or triblock (ABA or ABC) copolymer. 88. The method of any one of embodiments 21 to 87, wherein the amphiphilic polymer comprises the copolymer poly(N-vinylpyrrolidone)-b-PLA. 89. The method of any one of embodiments 21-88, wherein the amphiphilic polymer comprises at least one carboxylic acid, amide, amine, alkylene, dialkylsiloxane, ether, or alkylene sulfide monomer unit. 90. The method of any one of embodiments 21-89, wherein the amphiphilic polymer is a polyether block selected from the group consisting of an oligo(oxyethylene) block, a poly(oxyethylene) block, an oligo(oxypropylene) block, a poly(oxypropylene) block, an oligo(oxybutylene) block, and a poly(oxybutylene) block. 91. The method of any one of embodiments 21-90, wherein the amphiphilic polymer is a poly(butadiene)-poly(ethylene oxide) (PB-PEO) diblock copolymer, or the amphiphilic polymer is a poly(dimethylsiloxane)-poly(ethylene oxide) (PDMS-PEO) diblock copolymer, or a poly(dimethylsiloxane)-poly(acrylic acid) (PDMS-PAA). 92. The method of embodiment 91, wherein the PB-PEO diblock copolymer comprises 5-50 block PB and 5-50 block PEO, or the PB-PEO diblock copolymer preferably comprises 5-100 block PDMS and 5-100 block PEO. 93. The method of any one of aspects 21 to 92, wherein the amphiphilic polymer is a poly(lactide)-poly(ethylene oxide) / 1-palmitoyl-2-oleyl-sn-glycero-3-phospho-L-serine (PLA-PEO / POPC) copolymer, preferably the PLA-PEO / POPC has a ratio of PLA-PEO to POPC (e.g., PLA-PEO / POPC) of 75 to 25 (e.g., 75 / 25). 94. The method of any one of aspects 21 to 93, wherein the amphiphilic polymer is a poly(caprolactone)-poly(ethylene oxide) / 1-palmitoyl-2-oleyl-sn-glycero-3-phospho-L-serine (PCL-PEO / POPC) copolymer, preferably the PCL-PEO / POPC has a ratio of PCL-PEO to POPC (e.g., PCL-PEO / POPC) of 75 to 25 (e.g., 75 / 25). 95. The method of any one of embodiments 21 to 94, wherein the amphiphilic polymer is polybutadiene-polyethylene oxide (BD). 96. The first and / or second population of polymersomes comprises a diblock copolymer PBD 21 -PEO 14 (BD21) and / or triblock copolymer PMOXA 12 -PDMS 55 -PMOXA 12 The method of any one of embodiments 21 to 95, comprising: 97. The method of any one of the preceding embodiments, wherein the first and / or second population of polymersomes comprises one or more compartments. 98. The method of any one of the preceding embodiments, wherein the first and / or second population of polymersomes comprises one or more compartments, each of the one or more compartments encapsulating at least one peptide, protein, and nucleic acid, preferably wherein the at least one of the peptide, protein, and nucleic acid is immunogenic or antigenic, and further preferably wherein each of the one or more compartments is composed of the same or different amphiphilic polymers. 99. The first and / or second population of polymersomes comprises two or more compartments, the compartments comprising an outer block copolymer vesicle and at least one inner block copolymer vesicle, the at least one inner block copolymer vesicle being encapsulated within the outer block copolymer vesicle, preferably the outer block copolymer vesicle is (i) poly[styrene-b-poly(L-isocyanoalanine(2-thiophen-3-yl-ethyl)amide)] (PS-PIAT), (ii) poly(butadiene)-poly(ethylene oxide) (PBD-PEO); (iii) poly(ethylene oxide)-poly(caprolactone) (PEO-PCL); (iv) poly(ethylethylene)-poly(ethylene oxide) (PEE-PEO); (v) poly(ethylene oxide)-poly(lactic acid) (PEO-PLA); (vi) poly(isoprene)-poly(ethylene oxide) (PI-PEO); (vii) poly(2-vinylpyridine)-poly(ethylene oxide) (P2VP-PEO); (viii) poly(ethylene oxide)-poly(N-isopropylacrylamide) (PEO-PNIPAm); (ix) poly(styrene)-poly(acrylic acid) (PS-PAA); (x) poly(ethylene glycol)-polypropylene sulfide (PEG-PPS); (xi) poly(2-methyloxazoline)-poly(dimethylsiloxane)-poly(2-methyloxazoline) (PMOXA-PDMS-PMOXA); (xii) poly(ethylene oxide)-poly(dimethylsiloxane)-poly(2-methyloxazoline) (PEO-PDMS-PMOXA); (xiii) poly(methylphenylsilane)-poly(ethylene oxide) (PMPS-PEO-PMPS-PEO-PMPS), and (xiv) Poly(dimethylsiloxane)-poly(acrylic acid) (PDMS-PAA) and more preferably, the at least one inner block copolymer vesicle is a polymersome formed of a copolymer independently selected from the group consisting of (i) poly[styrene-b-poly(L-isocyanoalanine(2-thiophen-3-yl-ethyl)amide)] (PS-PIAT), (ii) poly(butadiene)-poly(ethylene oxide) (PBD-PEO); (iii) poly(ethylene oxide)-poly(caprolactone) (PEO-PCL); (iv) poly(ethylethylene)-poly(ethylene oxide) (PEE-PEO); (v) poly(ethylene oxide)-poly(lactic acid) (PEO-PLA); (vi) poly(isoprene)-poly(ethylene oxide) (PI-PEO); (vii) poly(2-vinylpyridine)-poly(ethylene oxide) (P2VP-PEO); (viii) poly(ethylene oxide)-poly(N-isopropylacrylamide) (PEO-PNIPAm); (ix) poly(styrene)-poly(acrylic acid) (PS-PAA); (x) poly(ethylene glycol)-polypropylene sulfide (PEG-PPS); (xi) poly(2-methyloxazoline)-poly(dimethylsiloxane)-poly(2-methyloxazoline) (PMOXA-PDMS-PMOXA); (xii) poly(ethylene oxide)-poly(dimethylsiloxane)-poly(2-methyloxazoline) (PEO-PDMS-PMOXA); (xiii) poly(methylphenylsilane)-poly(ethylene oxide) (PMPS-PEO-PMPS-PEO-PMPS), and (xiv) Poly(dimethylsiloxane)-poly(acrylic acid) (PDMS-PAA) The method of any one of the preceding aspects, wherein the polymersome is formed of a copolymer independently selected from the group consisting of: 100. The method of any one of the preceding embodiments, wherein the first population and / or the second population of polymersomes comprises a lipid polymer. 101. The method of any one of the preceding embodiments, wherein the adjuvant associated with the second population of polymersomes is selected from the group consisting of CpG oligodeoxynucleotides (i.e., CpG ODN), components from bacterial and mycobacterial cell walls, and proteins. 102. A method for producing an encapsulated antigen or adjuvant in a polymersome, comprising the steps of: (i) dissolving an amphiphilic polymer in chloroform, preferably the amphiphilic polymer is polybutadiene-polyethylene oxide (BD); (ii) drying the dissolved amphiphilic polymer to form a polymer film; (iii) adding a solubilized antigen or a soluble adjuvant to the amphiphilic polymer film of step (ii), the adjuvant being preferably selected from the group consisting of CpG oligodeoxynucleotides (i.e., CpG ODN), components from bacterial and mycobacterial cell walls and proteins, the antigen being (a) A polypeptide, preferably a polypeptide antigen, according to any one of the preceding aspects, more preferably the polypeptide antigen comprises a soluble portion of influenza hemagglutinin, swine influenza hemagglutinin, a spike protein, such as a porcine epidemic diarrhea virus spike protein, a spike protein of a human pathogenic coronavirus, such as a MERS-CoV spike protein or a SARS-CoV-2 spike protein, ovalbumin (OVA), a B16 peptide or an MC38 peptide, most preferably the polypeptide antigen is selected from the group consisting of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:7, SEQ ID NO:8, SEQ ID NO:9, SEQ ID NO:10, SEQ ID NO:11, SEQ ID NO:12-14, SEQ ID NOs:43-46, SEQ ID NOs:34-41, SEQ ID NOs:48-51 and SEQ ID NOs: is at least 60% or more (e.g., at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100%) identical to a polypeptide sequence selected from the group consisting of NO:65; (b) carbohydrates, (c) a polynucleotide which is not an antisense oligonucleotide and is preferably a DNA molecule or an mRNA molecule; (d) a combination of (a) and / or (b) and / or (c) A step selected from the group consisting of: (iv) rehydrating the polymer film of step (iii) to form polymer vesicles; (v) optionally purifying the polymer vesicles from step (iv) by filtering the polymer vesicles to obtain monodisperse vesicles; and / or (vi) Optionally, isolating the polymer vesicles of step (iv) or step (v) from unencapsulated antigen. 103. A method for producing an encapsulated antigen or adjuvant in a polymersome as defined in any one of embodiments 1 to 101. 104. A polymersome produced by a method for producing an encapsulated antigen or adjuvant in a polymersome as defined in embodiment 102 or embodiment 103. 1...

Claims

1. 1. A medicament for use in eliciting an immune response in a subject by administration of an antigen and an adjuvant, comprising a first and a second population of polymersomes, an antigen is associated with a first population of polymersomes and an adjuvant is associated with a second population of polymersomes, the first and second populations of polymersomes each comprising an amphiphilic synthetic block copolymer that forms a perivesicular membrane; a first population of polymersomes having an antigen encapsulated within the polymersomes and a second population of polymersomes having an adjuvant encapsulated within the polymersomes, the amphiphilic polymer being a poly(butadiene)-poly(ethylene oxide) (PB-PEO) diblock copolymer or the amphiphilic polymer being a poly(dimethylsiloxane)-poly(ethylene oxide) (PDMS-PEO) diblock copolymer; an antigen is associated with a first population of polymersomes and an adjuvant is associated with a second population of polymersomes, and the two polymersome populations are administered to a subject; The said medicine.

2. The pharmaceutical composition of claim 1, wherein the two polymersome populations are administered by a route of administration selected from the group consisting of oral administration, intranasal administration, administration to a mucosal surface, inhalation, intradermal administration, intraperitoneal administration, subcutaneous administration, intravenous administration and intramuscular administration.

3. The pharmaceutical composition according to any one of claims 1 to 2, wherein the subject is a mammal, including a human, or a non-mammal.

4. The pharmaceutical of claim 3, wherein the subject is a mammal and is vaccinated against a disease selected from the group consisting of cancer, viral infections and bacterial infections, the subject is preferably a human and is preferably vaccinated against a coronavirus infection, the coronavirus being preferably MERS-CoV, SARS-CoV-2 or SARS-CoV-1.

5. (a) the subject is a non-mammalian animal and is to be vaccinated against a disease selected from the group consisting of a viral infection and a bacterial infection; or (b) the mammal is a goat, sheep, cow, or pig, the animal preferably comprising: (i) is a pig and is vaccinated against porcine epidemic diarrhea virus; or (ii) is an ungulate and is vaccinated against FMD virus; The pharmaceutical composition according to claim 3.

6. The method according to any one of claims 1 to 5, wherein the encapsulated antigen is a soluble or solubilized antigen.

7. The antigen, preferably a soluble or solubilized encapsulated antigen, (i) a polypeptide, (ii) carbohydrates, (iii) a polynucleotide that is not an antisense oligonucleotide and is preferably a DNA molecule or an mRNA molecule; (iv) a combination of (i) and / or (ii) and / or (iii). The pharmaceutical composition according to any one of claims 1 to 6, selected from the group consisting of:

8. The method of any one of claims 1 to 7, wherein the first and / or second population of polymersomes are oxidatively stable.

9. the encapsulated antigen comprises a soluble portion of a membrane protein (MP) or a membrane-associated peptide (MAP); Preferably, the antigen comprises a soluble portion of influenza hemagglutinin, swine influenza hemagglutinin, a spike protein, such as the porcine epidemic diarrhea virus spike protein, a spike protein of a human pathogenic coronavirus, such as the MERS-CoV spike protein, the SARS-CoV-2 spike protein, or the SARS-CoV-1 spike protein, ovalbumin (OVA), the B16 peptide, or the MC38 peptide; More preferably, the antigen comprises a polypeptide having at least 60% identity to a polypeptide sequence selected from the group consisting of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:7, SEQ ID NO:8, SEQ ID NO:9, SEQ ID NO:10, SEQ ID NO:11, SEQ ID NO:12, SEQ ID NO:13, SEQ ID NO:14, SEQ ID NOs:43-46, SEQ ID NOs:34-41, SEQ ID NOs:48-51, and SEQ ID NO:

65. The pharmaceutical composition according to any one of claims 1 to 8.

10. The first and / or second population of polymersomes have the following characteristics: (i) the first and / or second population of polymersomes comprises an oxidatively stable membrane; and / or (ii) the first and / or second population of polymersomes are synthetic; and / or (iii) the first and / or second population of polymersomes have a diameter of more than 70 nm, preferably in the range of about 100 nm to about 1 μm, or about 100 nm to about 750 nm, or about 100 nm to about 500 nm, or about 125 nm to about 250 nm, about 140 nm to about 240 nm, about 150 nm to about 235 nm, about 170 nm to about 230 nm, or about 220 nm to about 180 nm, or about 190 nm to about 210 nm, and most preferably the diameter is about 200 nm; and / or (iv) the block copolymer or amphiphilic polymer is essentially non-immunogenic or essentially non-antigenic, preferably the block copolymer or amphiphilic polymer is non-immunogenic or non-antigenic; The pharmaceutical composition according to any one of claims 1 to 9, comprising one or more of:

11. The first and / or second population of polymersomes are Amphiphilic polymers comprising or consisting of diblock or triblock (ABA or ABC) copolymers The medicament according to any one of claims 1 to 10, comprising or formed from:

12. (a) the amphiphilic polymer is polybutadiene-polyethylene oxide (BD), or (b) the first and / or second population of polymersomes are polymerized with a diblock copolymer, PBD 21 -PEO 14 (BD21) or triblock copolymer PMOXA 12 -PDMS 55 -PMOXA 12 Including, The pharmaceutical composition according to any one of claims 1 to 11.

13. (i) the PB-PEO diblock copolymer comprises 5-50 block PB and 5-50 block PEO, or the PB-PDMS diblock copolymer preferably comprises 5-100 block PDMS and 5-100 block PEO; and / or (ii) the first and / or second population of polymersomes comprises a lipid polymer; The pharmaceutical composition according to any one of claims 1 to 12.

14. The pharmaceutical of any one of claims 1 to 13, wherein the adjuvant associated with the second population of polymersomes is selected from the group consisting of CpG oligodeoxynucleotides (i.e., CpG ODN), components from bacterial and mycobacterial cell walls, and proteins.

15. 1. A vaccine comprising a first and a second population of polymersomes, further comprising a pharma- ceutically acceptable excipient or carrier; an antigen is associated with a first population of polymersomes and an adjuvant is associated with a second population of polymersomes, the first and second populations of polymersomes comprising an amphiphilic synthetic block copolymer that forms a perivesicular membrane; a first population of polymersomes having an antigen encapsulated within the polymersomes and a second population of polymersomes having an adjuvant encapsulated within the polymersomes; The amphiphilic polymer is a poly(butadiene)-poly(ethylene oxide) (PB-PEO) diblock copolymer or the amphiphilic polymer is a poly(dimethylsiloxane)-poly(ethylene oxide) (PDMS-PEO) diblock copolymer.

16. 1. A medicament for use in treating or preventing an infectious disease, cancer or an autoimmune disease in a subject in need thereof, comprising a first and a second population of polymersomes, an antigen is associated with a first population of polymersomes and an adjuvant is associated with a second population of polymersomes, the first and second populations of polymersomes comprising an amphiphilic synthetic block copolymer that forms a perivesicular membrane; a first population of polymersomes having an antigen encapsulated within the polymersomes and a second population of polymersomes having an adjuvant encapsulated within the polymersomes; The above pharmaceutical, wherein the amphiphilic polymer is a poly(butadiene)-poly(ethylene oxide) (PB-PEO) diblock copolymer, or the amphiphilic polymer is a poly(dimethylsiloxane)-poly(ethylene oxide) (PDMS-PEO) diblock copolymer.

17. The pharmaceutical composition of claim 16, wherein the infectious disease is a viral infection or a bacterial infection.

18. 1. Use of a first and a second population of polymersomes for the manufacture of a medicament for the treatment of a disease selected from the group consisting of cancer, an autoimmune disease, and an infectious disease, comprising: an antigen is associated with a first population of polymersomes and an adjuvant is associated with a second population of polymersomes, the first and second populations of polymersomes each comprising an amphiphilic synthetic block copolymer that forms a perivesicular membrane; A use wherein a first population of polymersomes has an antigen encapsulated within the polymersomes and a second population of polymersomes has an adjuvant encapsulated within the polymersomes, and the amphiphilic polymer is a poly(butadiene)-poly(ethylene oxide) (PB-PEO) diblock copolymer or the amphiphilic polymer is a poly(dimethylsiloxane)-poly(ethylene oxide) (PDMS-PEO) diblock copolymer.

19. 20. The use for the manufacture of a medicament for treating a disease according to claim 18, wherein the infectious disease is a viral infection or a bacterial infection.

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