Respiratory syncytial virus vaccine and method of use

Abstract

This specification discloses respiratory syncytial virus vaccines and methods for delivering respiratory syncytial virus vaccines in which immunity is conferred to a target.

Description

[Technical Field]

[0001] Cross-reference of related applications This application claims priority to U.S. Provisional Patent Application No. 63 / 501,497, filed on 11 May 2023, and to U.S. Provisional Patent Application No. 63 / 627,541, filed on 31 January 2024, the contents of which are incorporated herein by reference in whole.

[0002] CRADA Declaration This invention was created in the course of a joint research and development agreement with the National Institutes of Health, an agency of the Department of Health and Human Services. The U.S. Government has certain rights to this invention.

[0003] The subject matter disclosed herein is respiratory syncytial virus vaccines and methods for conferring immunity to children using respiratory syncytial virus vaccines.

[0004] Sequence List This application includes a sequence listing submitted electronically in XML format, which is incorporated herein by reference in its entirety. The XML copy made on 18 April 2024 is named 01121-0051-00PCT-ST26.xml and has a size of 42,875 bytes. [Background technology]

[0005] RSV is the most important global cause of severe acute lower respiratory tract illness (LRI) in infants and children, and the most common cause of severe pneumonia requiring hospitalization in children. Globally, RSV is estimated to have caused approximately 33 million LRIs and 118,000 deaths in children under 5 years of age in 2015. It is estimated that more than 80% of all RSV-related LRIs (RSV-LRIs) and more than 50% of RSV-related deaths in low- and middle-income countries occurred in infants 6 months of age or older.

[0006] Intranasal RSV attenuated live vaccines are an attractive option for childhood immunization because they mimic mild, spontaneous infections and induce persistent cellular, humoral, topical, and systemic immunity. Several trials of RSV attenuated live vaccine candidates have indicated that these vaccines do not cause the increased incidence of vaccine-related RSV disease seen in children treated with formalin-inactivated RSV.

[0007] Advances have been made in understanding the genetic function of RSV, and in engineering attenuated RSV strains through rational design using reverse genetic systems, including strains attenuated by deletion of the NS2 gene, such as the RSVΔNS2 / Δ1313 / I1314L vaccine candidate provided herein. RSV NS2 is a type I and type III interferon antagonist encoded by the virus, which interferes with interferon induction and signaling. In chimpanzees, intranasal and intratracheal inoculation with recombinant wild-type RSV-A2 lacking the NS2 gene resulted in reduced replication in the upper and lower respiratory tracts compared to wild-type (wt)-RSV, and consequently, significant resistance to attack by wild-type RSV. Deletion of the NS2 gene leads to an increased interferon response to RSV infection, which has been demonstrated in calves for bovine RSV with NS1 or NS2 deletions. NS2 also functions as a pathogenic factor, promoting epithelial cell shedding in in vitro and hamster models, and its deletion may reduce peripheral airway obstruction, potentially improving the safety profile of such vaccine candidates. While deletion of the NS2 gene may be beneficial for vaccine safety, an additional deletion of codon 1313 in the polymerase (L) gene may also be beneficial, as this also confers mild temperature sensitivity (shutoff temperature of 38°C–39°C [100.4°F–102.2°F]), thus further increasing safety. Substitution of isoleucine (I) to leucine (L) at codon 1314 further stabilizes the deletion of codon 1313 genetically and phenotypically. [Overview of the project] [Means for solving the problem]

[0008] The embodiments provided herein, in particular, are as follows:

[0009] This specification discloses a method for conferring immunity to respiratory syncytial virus (RSV) infection in children, comprising administering a certain dose of a spray RSV vaccine to the children, wherein the RSV vaccine comprises an effective amount of attenuated live RSV ΔNS2 / Δ1313 / I1314L.

[0010] This specification discloses a method for conferring immunity to respiratory syncytial virus (RSV) infection in children, comprising administering a certain dose of RSV vaccine to a child using an intranasal spray delivery device, wherein the RSV vaccine comprises an effective amount of attenuated live RSV ΔNS2 / Δ1313 / I1314L.

[0011] This specification discloses a method for preventing or reducing the likelihood of RSV infection in children, or a method for preventing or reducing at least one symptom of RSV infection, the method comprising administering a certain dose of an RSV vaccine to a child, wherein the RSV vaccine comprises an effective amount of attenuated live RSV ΔNS2 / Δ1313 / I1314L.

[0012] This specification provides a method for conferring immunity to respiratory syncytial virus (RSV) infection in children, comprising administering a certain dose of a spray RSV vaccine to the children, wherein the RSV vaccine contains an effective amount of attenuated live RSV ΔNS2 / Δ1313 / I1314L, and the effective amount of RSV is about 5 to about 9 log per dose. 10 Contains plaque-forming units (PFUs), with an optional dose of approximately 5.6 log per dose. 10 A method used by PFU is disclosed.

[0013] This specification describes a method for conferring immunity against respiratory syncytial virus (RSV) infection in pediatric subjects, the method comprising administering a certain dose of a spray RSV vaccine to a pediatric subject, wherein the RSV vaccine comprises an effective amount of an attenuated live RSV ΔNS2 / Δ1313 / I1314L, and the effective amount of RSV is about 5.4 log 10 PFU per dose, about 5.6 log 10 PFU per dose, about 6.2 log 10 PFU per dose, about 6.4 log 10 PFU per dose, or about 7.0 log 10 PFU per dose. A method is disclosed.

[0014] This specification describes a method for conferring immunity against respiratory syncytial virus (RSV) infection in pediatric subjects, the method comprising administering a certain dose of an RSV vaccine to a pediatric subject, wherein the RSV vaccine comprises an effective amount of an attenuated live RSV ΔNS2 / Δ1313 / I1314L, and the effective amount of RSV is about 5 to about 9 log 10 plaque forming units (PFU) per dose, optionally wherein the dose is about 5.6 log 10 PFU per dose. A method is disclosed.

[0015] This specification describes a method for conferring immunity against respiratory syncytial virus (RSV) infection in pediatric subjects, the method comprising administering a certain dose of an RSV vaccine to a pediatric subject, wherein the RSV vaccine comprises an effective amount of an attenuated live RSV ΔNS2 / Δ1313 / I1314L, and the effective amount of RSV is about 5.4 log 10 PFU per dose, about 5.6 log 10 plaque forming units (PFU) per dose, about 6.2 log 10 PFU per dose, about 6.4 log 10 PFU per dose, or about 7.0 log 10 PFU per dose. A method is disclosed.

[0016] In some embodiments, the effective amount of RSV is about 5 log 10 PFU to about 9 log per dose10 PFU, optional, approximately 5.4 log per dose. 10 PFU, approximately 5.6 log per dose 10 PFU, approximately 6.2 log per dose 10 PFU, approximately 6.4 log per dose 10 PFU, or approximately 7.0 log per dose. 10 Contains PFU. In some embodiments, the RSV vaccine is delivered intranasally to each nostril of the pediatric subject, at a dose of approximately half the total dose. In some embodiments, the RSV vaccine is delivered in a dose of approximately 0.2 mL, with approximately 0.1 mL delivered to each nostril of the pediatric subject. In some embodiments, the RSV vaccine is delivered sequentially or simultaneously to each nostril of the pediatric subject.

[0017] In some embodiments, the method includes delivering a second dose of the RSV vaccine. In some embodiments, the second dose is approximately 5.4 log 10 Contains PFU. In some embodiments, the second dose is approximately 5.6 log 10 Contains PFU. In some embodiments, the second dose is approximately 6.2 log 10 Contains PFU. In some embodiments, the second dose is approximately 6.4 log 10 Contains PFU. In some embodiments, the second dose is approximately 7.0 log 10 Contains PFU. In some embodiments, the second dose is approximately 5 log 10 PFU ~ approximately 9 log 10 Contains PFU. In some embodiments, the second dose is administered approximately 40–50, 45–55, 55–60, 52–60, or 60–65 days after the first dose. In some embodiments, the second dose is administered at least 56 days after the first dose. In some embodiments, the second dose is delivered intranasally to each nostril of the pediatric subject, approximately half of the delivered dose. In some embodiments, the second dose of RSV vaccine is delivered in approximately 0.2 mL, with approximately 0.1 mL delivered to each nostril of the pediatric subject. In some embodiments, the RSV vaccine is delivered sequentially or simultaneously to each nostril of the pediatric subject.

[0018] In some embodiments, the subjects are children approximately 6 to 22 months old. In some embodiments, the subjects are children approximately 6 to 18 months old. In some embodiments, the subjects are children at least 6 months old. In some embodiments, the subjects are full-term babies. In some embodiments, the subjects are premature babies.

[0019] In some embodiments, the dose of RSV vaccine is administered to a pediatric subject using an intranasal spray delivery device. In some embodiments, the intranasal spray delivery device includes a spray nozzle for spraying the RSV vaccine for administration to a pediatric subject. In some embodiments, the intranasal spray delivery device includes an outer cylinder, a plunger, and a dose divider. In some embodiments, the method includes advancing the plunger a first distance within the outer cylinder to deliver approximately half of the dose of RSV vaccine to the pediatric subject's first nostril. In some embodiments, the method includes removing the dose divider from the plunger. In some embodiments, the method includes advancing the plunger a second distance within the outer cylinder to deliver approximately half of the dose to the pediatric subject's second nostril.

[0020] In some embodiments, the intranasal spray delivery device has an average droplet diameter of approximately 10-120 μm. v50 Delivers the average droplet diameter D delivered to each nostril of a child subject. v50The droplet sizes are approximately 10–120 μm, 30–120 μm, 50–110 μm, 70–110 μm, or 80–110 μm. In some embodiments, the intranasal spray delivery device delivers an average droplet diameter Dv50 of at least 30 μm, at least 50 μm, at least 70 μm, at least 80 μm, at least 110 μm, or at least 120 μm. In some embodiments, the average shot weight delivered to each nostril in a pediatric subject is between approximately 30 mg–200 mg, 50 mg–175 mg, 70 mg–160 mg, 80 mg–150 mg, 95 mg–135 mg, 100 mg–130 mg, 100 mg–130 mg, or 105 mg–130 mg. In some embodiments, the average shot volume delivered to each nostril in a child is approximately 85 μL to 120 μL, approximately 90 μL to 115 μL, or approximately 95 μL to 115 μL.

[0021] In some embodiments, deletion of the codon encoding serine at position 1313 of the L protein in attenuated live RSV results in an amino acid deletion in the L protein (Δ1313). In some embodiments, substitution of isoleucine at position 1314 in attenuated live RSV with leucine results in a genetically stabilizing mutation in the L gene (I1314L). In some embodiments, attenuated live RSV includes large polymerase protein (L), phosphoprotein (P), nucleocapsid protein (N), M2-1 protein nonstructural protein 1 (NS1), glycoprotein (G), fusion protein (F), matrix protein (M), M2-2 protein, and small hydrophobic protein (SH); and a genome or antigenome including a deletion of a codon encoding serine at position 1313 of the L protein or the corresponding position; a mutation at amino acid sequence residue 1314 of the L protein or the corresponding position, wherein the mutation at L protein amino acid sequence residue 1314 is an amino acid substitution from isoleucine to leucine, and the leucine is a mutation encoded by a codon represented as CTG; a deletion of the NS2 gene; and a nucleotide modification at position 14456 of SEQ ID NO: 1, corresponding to a change from thymine (T) to adenine (A).

[0022] In some embodiments, at least one symptom is selected from the onset or development of upper respiratory tract RSV infection, the onset or development of lower respiratory tract RSV infection, the onset or development of otitis media, progression of upper respiratory tract RSV infection to lower respiratory tract RSV infection, or progression to otitis media. In some embodiments, at least one symptom is selected from asthma, wheezing, or a combination thereof.

[0023] Disclosed herein is the use of an intranasal spray delivery device for administering a certain dose of RSV vaccine to a child, wherein the RSV vaccine contains an effective amount of RSV ΔNS2 / Δ1313 / I1314L.

[0024] Disclosed herein is the use of an RSV vaccine for the manufacture of a pharmaceutical product for preventing or reducing the likelihood of infection of a child with the RSV virus, wherein the RSV vaccine contains an effective amount of RSV ΔNS2 / Δ1313 / I1314L.

[0025] In some embodiments, the effective amount of RSV is about 5 log 10 PFU ~ approximately 9 log per dose 10 Includes PFU. In some embodiments, the effective amount of RSV is about 5.4 log 10 PFU, approximately 5.6log 10 PFU, approximately 6.2log 10 PFU, approximately 6.4log 10 PFU, or approximately 7.0 log 10 Contains PFU. In some embodiments, the RSV vaccine is delivered intranasally to each nostril of the pediatric subject, at a dose of approximately half the total dose. In some embodiments, the RSV vaccine is delivered in a dose of approximately 0.2 mL, with approximately 0.1 mL delivered to each nostril of the pediatric subject. In some embodiments, the RSV vaccine is delivered sequentially or simultaneously to each nostril of the pediatric subject.

[0026] In some embodiments, this use involves delivering a second dose of the RSV vaccine. In some embodiments, the second dose is approximately 5.4 log 10Contains PFU. In some embodiments, the second dose is approximately 5.6 log 10 Contains PFU. In some embodiments, the second dose is approximately 6.2 log 10 Contains PFU. In some embodiments, the second dose is approximately 6.4 log 10 Contains PFU. In some embodiments, the second dose is approximately 7.0 log 10 Contains PFU. In some embodiments, the second dose is approximately 5 log 10 PFU ~ approximately 9 log 10 Contains PFU. In some embodiments, the second dose is administered approximately 40–50, 45–55, 55–60, 52–60, or 60–65 days after the first dose. In some embodiments, the second dose is administered at least 56 days after the first dose. In some embodiments, the second dose is delivered intranasally to each nostril of the pediatric subject, approximately half of the delivered dose. In some embodiments, the second dose of RSV vaccine is delivered in approximately 0.2 mL, with approximately 0.1 mL delivered to each nostril of the pediatric subject. In some embodiments, the RSV vaccine is delivered sequentially or simultaneously to each nostril of the pediatric subject.

[0027] In some embodiments, the subjects are children approximately 6 to 22 months old. In some embodiments, the subjects are children approximately 6 to 18 months old. In some embodiments, the subjects are children at least 6 months old. In some embodiments, the subjects are full-term babies. In some embodiments, the subjects are premature babies.

[0028] In some embodiments, the dose of RSV vaccine is administered to a pediatric subject using an intranasal spray delivery device. In some embodiments, the intranasal spray delivery device includes a spray nozzle for spraying the RSV vaccine for administration to a pediatric subject. In some embodiments, the intranasal spray delivery device includes an outer cylinder, a plunger, and a dose divider. In some embodiments, the method includes advancing the plunger a first distance within the outer cylinder to deliver approximately half of the dose of RSV vaccine to the first nostril of the pediatric subject. In some embodiments, this use includes removing the dose divider from the plunger. In some embodiments, this use includes advancing the plunger a second distance within the outer cylinder to deliver approximately half of the dose to the second nostril of the pediatric subject.

[0029] In some embodiments, the intranasal spray delivery device has an average droplet diameter of approximately 10-120 μm. v50 Delivers the average droplet diameter D delivered to each nostril of a child subject. v50 The droplet sizes are approximately 10–120 μm, 30–120 μm, 50–110 μm, 70–110 μm, or 80–110 μm. In some embodiments, the intranasal spray delivery device delivers an average droplet diameter Dv50 of at least 30 μm, at least 50 μm, at least 70 μm, at least 80 μm, at least 110 μm, or at least 120 μm. In some embodiments, the average shot weight delivered to each nostril in a pediatric subject is between approximately 30 mg–200 mg, 50 mg–175 mg, 70 mg–160 mg, 80 mg–150 mg, 95 mg–135 mg, 100 mg–130 mg, 100 mg–130 mg, or 105 mg–130 mg. In some embodiments, the average shot volume delivered to each nostril in a child is approximately 85 μL to 120 μL, approximately 90 μL to 115 μL, or approximately 95 μL to 115 μL.

[0030] In some embodiments, deletion of the codon encoding serine at position 1313 of the L protein in attenuated live RSV results in an amino acid deletion in the L protein (Δ1313). In some embodiments, substitution of isoleucine at position 1314 in attenuated live RSV with leucine results in a genetically stabilizing mutation in the L gene (I1314L). In some embodiments, attenuated live RSV includes large polymerase protein (L), phosphoprotein (P), nucleocapsid protein (N), M2-1 protein nonstructural protein 1 (NS1), glycoprotein (G), fusion protein (F), matrix protein (M), M2-2 protein, and small hydrophobic protein (SH); and a genome or antigenome including a deletion of a codon encoding serine at position 1313 of the L protein or the corresponding position; a mutation at amino acid sequence residue 1314 of the L protein or the corresponding position, wherein the mutation at L protein amino acid sequence residue 1314 is an amino acid substitution from isoleucine to leucine, and the leucine is a mutation encoded by a codon represented as CTG; a deletion of the NS2 gene; and a nucleotide modification at position 14456 of SEQ ID NO: 1, corresponding to a change from thymine (T) to adenine (A).

[0031] This specification discloses a kit comprising a certain dose of an RSV vaccine containing an effective amount of attenuated live RSV ΔNS2 / Δ1313 / I1314L, and an intranasal spray delivery device for administering the RSV vaccine to children.

[0032] In some embodiments, the effective amount of RSV is about 5 log 10 PFU ~ approximately 9 log per dose 10 Includes PFU. In some embodiments, the effective amount of RSV is about 5.4 log 10 PFU and / or approximately 5.6 log 10 PFU and / or approximately 6.2 log 10 PFU and / or approximately 6.4log 10 PFU and / or approximately 7.0log 10Contains PFU. In some embodiments, the kit further includes a second dose of RSV vaccine. In some embodiments, the second dose is approximately 5 log per second dose. 10 PFU ~ approximately 9 log 10 Contains an effective amount of RSV including PFU. In some embodiments, the second dose is approximately 5.4 log per second dose. 10 PFU and / or approximately 5.6 log 10 PFU and / or approximately 6.2 log 10 PFU and / or approximately 6.4log 10 PFU and / or approximately 7.0log 10 Contains an effective amount of RSV including PFU. In some embodiments, the first and / or second doses contain a volume of approximately 0.2 mL.

[0033] In some embodiments, the intranasal spray delivery device includes a spray nozzle for spraying the RSV vaccine. In some embodiments, the intranasal spray delivery device includes an outer cylinder, a plunger, and a dose divider. In some embodiments, the intranasal spray delivery device has an average droplet diameter D of approximately 10-120 μm. v50 The device delivers the following. In some embodiments, the intranasal spray delivery device delivers an average droplet diameter Dv50 of at least 30 μm, at least 50 μm, at least 70 μm, at least 80 μm, at least 110 μm, or at least 120 μm. In some embodiments, the intranasal spray delivery device delivers an average shot weight between approximately 30 mg and approximately 200 mg, approximately 50 mg and approximately 175 mg, approximately 70 mg and approximately 160 mg, approximately 80 mg and approximately 150 mg, 95 mg and approximately 135 mg, approximately 100 mg and approximately 130 mg, approximately 100 mg and approximately 130 mg, or approximately 105 mg and approximately 130 mg per half dose. In some embodiments, the intranasal spray delivery device delivers an average shot volume of approximately 85 μL and approximately 120 μL, approximately 90 μL and approximately 115 μL, or approximately 95 μL and approximately 115 μL per half dose.

[0034] This specification discloses recombinant infectious respiratory syncytial virus comprising a large polymerase protein (L), a phosphoprotein (P), a nucleocapsid protein (N), an M2-1 protein nonstructural protein 1 (NS1), a glycoprotein (G), a fusion protein (F), a matrix protein (M), an M2-2 protein, and a small hydrophobic protein (SH); and a genome or antigenome including a deletion of a codon encoding serine at position 1313 of the L protein, or a corresponding position; a mutation at amino acid sequence residue 1314 of the L protein, or a corresponding position, wherein the mutation at amino acid sequence residue 1314 of the L protein is an amino acid substitution from isoleucine to leucine, and the leucine is encoded by a codon represented as CTG; a deletion of the NS2 gene; and a nucleotide modification at position 14456 of Sequence ID No. 1, corresponding to a change from thymine (T) to adenine (A). [Brief explanation of the drawing]

[0035] [Figure 1] The Phase I / II test protocol according to an embodiment of this disclosure is shown. [Figure 2] This disclosure shows an intranasal spray delivery device according to one embodiment. [Figure 3] A dose divider according to one embodiment of this disclosure is shown. [Figure 4] This disclosure shows an intranasal spray delivery device equipped with a dose divider according to one embodiment of this disclosure. [Figure 5] The genome structure of RSV ΔNS2 / Δ1313 / I1314L is shown as an example. [Modes for carrying out the invention]

[0036] This specification describes a method for conferring immunity to respiratory syncytial virus (RSV) infection to subjects. This method may include administering an RSV vaccine to subjects using an intranasal spray delivery device.

[0037] Unless otherwise specified, all technical terms, notations, and other scientific terminology used herein are intended to have meanings generally understood by those skilled in the art in the field relating to this invention. In some cases, terms having generally understood meanings are defined herein for clarity and / or for easy reference, but the inclusion of such definitions herein should not necessarily be interpreted as indicating a difference from the commonly understood meaning in the art. The techniques and procedures described or referenced herein are generally well understood and commonly employed by those skilled in the art using conventional methodologies, such as the widely used molecular cloning methodology described, for example, in Sambrook et al., Molecular Cloning: A Laboratory Manual 4th ed. (2012), Cold Spring Harbor Laboratory Press, Cold Spring Harbor, NY. Where appropriate, procedures involving the use of commercially available kits and reagents are generally carried out according to the manufacturer's defined protocols and conditions unless otherwise noted.

[0038] I. Definition Unless otherwise specified, the following terms and phrases are intended to have the following meanings when used herein:

[0039] As used herein, “attenuated live virus” refers to a viable virus that, upon administration to a subject, exhibits a reduction, attenuation, or absence of clinical signs of the disease. “Attenuated live vaccine” contains an attenuated live virus.

[0040] A “vector” or “vector-based” virus or vaccine, as used herein, includes a virus that has been modified to express one or more heterologous antigens. In some cases, a “vector” or “vector-based” vaccine is also a live attenuated vaccine that, upon administration to a subject, exhibits a reduction, attenuation, or absence of clinical signs of a disease.

[0041] When used herein, “prevention” refers to the prevention of the onset of a particular disease, disorder, or condition (e.g., RSV infection), avoidance of disease onset, delay of onset, and / or reduction of the frequency and / or severity of one or more symptoms. In some embodiments, prevention is determined on a population basis, i.e., a drug is considered to “prevent” a particular disease, disorder, or condition if a statistically significant reduction in the onset, frequency, and / or severity of one or more symptoms of that disease, disorder, or condition is observed in a population susceptible to that disease, disorder, or condition.

[0042] As used herein, the terms “vaccination” or “to vaccinate” refer to, for example, the administration of a composition intended to induce an immune response to a disease-causing pathogen. Vaccination may be administered before, during, and / or after exposure to a disease-causing pathogen, and / or until the onset of one or more symptoms, and in some embodiments, before, during, and / or immediately after exposure to the pathogen. In some embodiments, vaccination may involve multiple administrations of a vaccine composition at appropriate time intervals.

[0043] As used herein, “RSV ΔNS2 / Δ1313 / I1314L” refers to RSV ΔNS2 / Δ1313 / I1314L(NIH) or RSV ΔNS2 / Δ1313 / I1314L(Sanofi). Each of ΔNS2 / Δ1313 / I1314L(NIH) and RSV ΔNS2 / Δ1313 / I1314L(Sanofi) contains attenuated live RSV having (i) a 523 nucleotide (nt) deletion in the NS2 gene (ΔNS2), (ii) an amino acid deletion in the L protein, and (iii) a genetically stabilizing mutation in the L gene (see Figure 5). The attenuated live RSV of RSV ΔNS2 / Δ1313 / I1314L(Sanofi) also includes a nucleotide modification at position 14456 of sequence number 1, which corresponds to a thymine (T) to adenine (A) change in the non-coding region.

[0044] As used herein, “RSV ΔNS2 / Δ1313 / I1314L vaccine” refers to either “RSV ΔNS2 / Δ1313 / I1314L (NIH) vaccine” or “RSV ΔNS2 / Δ1313 / I1314L (Sanofi) vaccine.” RSV ΔNS2 / Δ1313 / I1314L (NIH) vaccine contains an effective dose of RSV ΔNS2 / Δ1313 / I1314L (NIH). RSV ΔNS2 / Δ1313 / I1314L (Sanofi) vaccine contains an effective dose of RSV ΔNS2 / Δ1313 / I1314L (Sanofi).

[0045] As used herein, “immune response” refers to the response of cells of the immune system, such as B cells, T cells, dendritic cells, macrophages, or polymorphonuclear leukocytes, to a stimulus such as an antigen or vaccine. An immune response may include any cells of the body involved in the host defense response, including, for example, epithelial cells that secrete interferon or cytokines. An immune response includes, but is not limited to, innate and / or adaptive immune responses. As used herein, “protective immune response” refers to an immune response that protects an object from infection (e.g., preventing infection or the development of a disease associated with infection). Methods for measuring an immune response include, for example, measuring the proliferation and / or activity of lymphocytes (such as B cells or T cells), the secretion of cytokines or chemokines, inflammation, and antibody production. An “antibody response” is an immune response in which antibodies are produced.

[0046] When used herein, "to confer immunity" refers to an action that elicits an immune response from a subject or an action that protects the subject from infection.

[0047] As used herein, "adjuvant" refers to a substance or medium that nonspecifically enhances the immune response to an antigen. Examples of adjuvants include, but are not limited to, suspensions of minerals (e.g., alum, aluminum hydroxide, or phosphate) on which an antigen has been adsorbed; and water-in-oil or oil-in-water emulsions in which an antigen solution is emulsified in mineral oil or water (e.g., Freund's incomplete adjuvant). Sometimes, dead mycobacteria are included to further enhance antigenicity (e.g., Freund's complete adjuvant). Immunostimulatory oligonucleotides (e.g., CpG motifs) can also be used as adjuvants (see, for example, U.S. Patent Nos. 6,194,388; 6,207,646; 6,214,806; 6,218,371; 6,239,116; 6,339,068; 6,406,705; and 6,429,199). Adjuvants may also include biomolecules such as Toll-like receptor (TLR) agonists and costimulatory molecules. Examples of biological adjuvants include, but are not limited to, IL-2, RANTES, GM-CSF, TNF-α, IFN-γ, G-CSF, LFA-3, CD72, B7-1, B7-2, OX-40L, 4-1BBL, or combinations thereof.

[0048] As used herein, “liquid” is given its conventional meaning, and “freezing liquid” is a liquid in a solid state, distinct from a liquid state.

[0049] "Formulation" refers to a composition containing an active pharmaceutical or biological raw material together with one or more additional components. The term "formulation" is used herein synonymously with the terms "pharmaceutical composition," "vaccine composition," and "vaccine formulation." Additional components that may be included as needed include pharmaceutically acceptable excipients, additives, diluents, buffers, sugars, amino acids (such as glycine, glutamine, asparagine, arginine, or lysine), chelating agents, surfactants, polyols, bulking agents, stabilizers, lyophilization protectants, solubilizers, emulsifiers, salts, adjuvants, isotonic enhancers (such as alkali metal halides, e.g., sodium or potassium chloride, mannitol, or sorbitol), delivery media, and antimicrobial preservatives.

[0050] As used herein, “to treat,” “to treat,” and “treatment” mean any administration or application of a therapeutic agent to the disease or disorder of interest, and include inhibiting the disease, preventing its onset, alleviating one or more symptoms of the disease, curing the disease, or preventing the recurrence of one or more symptoms of the disease. In some cases, treatment includes reducing or improving the progression, severity, and / or duration of upper and / or lower respiratory tract RSV infection, otitis media, or related symptoms or respiratory conditions (such as asthma, wheezing, or a combination thereof).

[0051] As used herein, “therapeutic dose” or “effective dose” means the amount of a composition or its active ingredient that is sufficient to provide a beneficial effect, or, in other cases, sufficient to reduce an adverse and unbeneficial event in the individual to whom the composition is to be administered. “Therapeutic dose” or “effective dose” as used herein means the dose that produces one or more desired or preferred (e.g., beneficial) effects for which it is intended to be administered, and such administration is given one or more times within a given period. The exact dose will depend on the therapeutic purpose and may be determined using known techniques (see, for example, Lieberman, Pharmaceutical Dosage Forms (vols. 1-3, 1992); Lloyd, The Art, Science and Technology of Pharmaceutical Compounding (1999); and Pickar, Dosage Calculations (1999)).

[0052] The terms “approximately” or “about” are used herein to mean roughly, roughly, around, within or between. When used in conjunction with a numerical range, the term “about” modifies the range by extending the boundary above and below the indicated number. Generally, the term “about” can modify a number that is above or below a given value by raising or lowering it by, for example, a difference of 10 percent. In some embodiments, the term indicates a deviation of ±10%, ±5%, ±4%, ±3%, ±2%, ±1%, ±0.9%, ±0.8%, ±0.7%, ±0.6%, ±0.5%, ±0.4%, ±0.3%, ±0.2%, ±0.1%, ±0.05%, or ±0.01% from the indicated number. In some embodiments, “about” indicates a deviation of ±10% from the indicated number. In some embodiments, "approximately" indicates a deviation of ±5% from the indicated value. In some embodiments, "approximately" indicates a deviation of ±4% from the indicated value. In some embodiments, "approximately" indicates a deviation of ±3% from the indicated value. In some embodiments, "approximately" indicates a deviation of ±2% from the indicated value. In some embodiments, "approximately" indicates a deviation of ±1% from the indicated value. In some embodiments, "approximately" indicates a deviation of ±0.9% from the indicated value. In some embodiments, "approximately" indicates a deviation of ±0.8% from the indicated value. In some embodiments, "approximately" indicates a deviation of ±0.7% from the indicated value. In some embodiments, "approximately" indicates a deviation of ±0.6% from the indicated value. In some embodiments, "approximately" indicates a deviation of ±0.5% from the indicated value. In some embodiments, "approximately" indicates a deviation of ±0.4% from the indicated value. In some embodiments, "approximately" indicates a deviation of ±0.3% from the indicated value. In some embodiments, "approximately" indicates a deviation of ±0.2% from the indicated value. In some embodiments, "approximately" indicates a deviation of ±0.1% from the indicated value.In some embodiments, “approximately” indicates a deviation of ±0.05% from the indicated value. In some embodiments, “approximately” indicates a deviation of ±0.01% from the indicated value. All ranges shown herein are intended to encompass the upper and lower limits of that range.

[0053] The term "child subjects" refers to subjects aged 21 years or younger at the time of immunization. Child subgroups are further characterized as (i) neonates – from birth to 28 days old; (ii) infants and toddlers – from 29 days old to under 2 years old; (iii) children – from 2 years old to under 12 years old; and (iv) adolescents – aged 12 to 21 years. In some embodiments, child subjects may be 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 year old or younger. In some embodiments, child subjects may be at least 6 months old. In some embodiments, child subjects may be 6 months to 18 years old. In some embodiments, child subjects may be 6 months to 10 years old. In some embodiments, child subjects may be 4 months to 4 years old. In some embodiments, child subjects may be 6 to 18 months old. In some embodiments, the child subject may be between 6 and 22 months of age. In some embodiments, the child subject may be between 6 and 24 months of age. Further age ranges may also be included in the child subject. In some embodiments, the child subject was born at full term, as defined herein as 37 weeks or more of gestation. In some embodiments, the child subject was born prematurely, as defined herein as 28 to 36 weeks of gestation.

[0054] Herein, specific embodiments will be referenced in detail, examples of which are illustrated in the accompanying drawings. These embodiments are described in conjunction with the exemplary embodiments, but it will be understood that this disclosure is not intended to limit the disclosure to those embodiments. Rather, the disclosure is intended to encompass all alternatives, variations, and equivalents, which may fall within the scope of the disclosure as defined by the accompanying claims and the embodiments included.

[0055] Before describing this instruction in detail, it should be understood that this disclosure is not limited to, and therefore may vary from, a specific composition or method step. It should be noted that, as used herein and in the appended claims, the singular forms "a," "an," and "the" include plural references unless specifically indicated in the context. Thus, for example, "a conjugate" includes multiple conjugates, and "a cell" includes multiple cells, and so on.

[0056] Numerical ranges include the numbers that define the range. Measured and measurable values ​​are understood to be approximations, taking into account significant figures and measurement errors. Furthermore, the use of “comprise,” “comprises,” “comprising,” “contain,” “contains,” “containing,” “include,” “includes,” and “including” is not intended to be limiting. The general and detailed explanations above are for illustrative and explanatory purposes only and should not be understood as limiting this instruction.

[0057] Unless otherwise specifically noted herein, embodiments described herein as “comprising” various components are also intended to “consist of” or “consisting essentially of” the components described; embodiments described herein as “consisting of” various components are also intended to “comprising” or “consisting essentially of” the components described; and embodiments described herein as “consisting essentially of,” “consisting of,” or “comprising” various components are also intended to “consisting essentially of” the components described (this synonymy does not apply to the use of these terms in the claims). The term “or” is used in an inclusive sense unless specifically indicated in context, i.e., it is used equivalently to “and / or.”

[0058] The section headings used herein are for organizational purposes only and should not be construed as limiting the preferred subject matter described herein in any way. In the event that any material referenced herein conflicts with any term defined herein or any other expression of the content herein, this specification shall prevail. While these instructions are described in conjunction with various embodiments, they are not intended to be limited to such embodiments. Rather, these instructions include various alternatives, modifications, and equivalents, as will be understood by those skilled in the art.

[0059] II. Exemplary Methods and Uses In certain embodiments, a method is provided for conferring immunity to respiratory syncytial virus (RSV) infection to a subject, comprising administering a certain spray dose of an RSV vaccine. In some embodiments, a method is provided for conferring immunity to RSV infection to a subject, comprising administering a certain dose of an RSV vaccine using an intranasal spray delivery device.

[0060] In some embodiments, a method for conferring immunity to RSV infection to a subject includes administering a certain spray dose of an RSV vaccine containing attenuated live RSV. In some embodiments, a method for conferring immunity to RSV infection to a subject includes administering a certain dose of an RSV vaccine containing attenuated live RSV using an intranasal spray delivery device. In some embodiments, a method is provided for conferring immunity to RSV infection to a subject, comprising administering a certain spray dose of an RSV vaccine using an optional intranasal spray delivery device, wherein the RSV vaccine comprises an effective amount of attenuated live RSV having (i) a 523 nucleotide (nt) deletion in the NS2 gene (ΔNS2), (ii) an amino acid deletion in the L protein, and (iii) a genetically stabilizing mutation in the L gene (RSV ΔNS2 / Δ1313 / I1314L(NIH)), or RSV further comprising a nucleotide modification at position 14456 of SEQ ID NO: 1 in a non-coding region corresponding to a change from thymine (T) to adenine (A) (RSV ΔNS2 / Δ1313 / I1314L(Sanofi)). In some embodiments, deletion of the codon encoding serine at position 1313 of the L protein results in an amino acid deletion in the L protein (Δ1313). In some embodiments, an amino acid substitution from isoleucine to leucine at position 1314 induces a genetically stabilizing mutation in the L gene (I1314L).

[0061] In some embodiments, a method is provided for conferring immunity to RSV infection in a child subject, comprising administering a certain spray dose of RSV vaccine. In some embodiments, a method is provided for conferring immunity to RSV infection in a child subject, comprising administering a certain dose of RSV vaccine using an intranasal spray delivery device. In certain embodiments, the child subject may be at least 6 months old. In some embodiments, the child subject may be between 6 and 18 months old. In some embodiments, the child subject may be between 6 and 22 months old. In various embodiments, the child subject may be between 6 and 24 months old. In some embodiments, the child subject was born at full term. In some embodiments, the child subject was born prematurely.

[0062] In some embodiments, a method is provided for preventing or reducing the likelihood of a target RSV infection or for preventing or reducing at least one symptom of an RSV infection, comprising administering a certain spray dose of an RSV vaccine. In some embodiments, a method is provided for preventing or reducing the likelihood of a target RSV infection or for preventing or reducing at least one symptom of an RSV infection, comprising administering a certain dose of an RSV vaccine using an intranasal spray delivery device.

[0063] In some embodiments, a method for preventing or reducing the likelihood of RSV infection in a target group, or for preventing or reducing at least one symptom of RSV infection, includes administering a certain spray dose of an RSV vaccine containing attenuated live RSV. In some embodiments, a method for preventing or reducing the likelihood of RSV infection in a target group, or for preventing or reducing at least one symptom of RSV infection, includes administering a certain dose of an RSV vaccine containing attenuated live RSV using an intranasal spray delivery device. In some embodiments, a method is provided for preventing or reducing the likelihood of RSV infection in a target group, or for preventing or reducing at least one symptom of RSV infection, comprising administering a certain spray dose of an RSV vaccine, optionally using an intranasal spray delivery device, wherein the RSV vaccine contains an effective amount of RSV ΔNS2 / Δ1313 / I1314L. In some embodiments, deletion of the codon encoding serine at position 1313 of the L protein results in an amino acid deletion in the L protein (Δ1313). In some embodiments, an amino acid substitution from isoleucine to leucine at position 1314 induces a genetically stabilizing mutation in the L gene (I1314L).

[0064] In some embodiments, a method is provided for preventing or reducing the likelihood of RSV infection in a child, or for preventing or reducing at least one symptom of RSV infection, comprising administering a certain spray dose of RSV vaccine. In some embodiments, a method is provided for preventing or reducing the likelihood of RSV infection in a child, or for preventing or reducing at least one symptom of RSV infection, comprising administering a certain dose of RSV vaccine using an intranasal spray delivery device. In certain embodiments, the child subject may be at least 6 months old. In some embodiments, the child subject may be between 6 and 18 months old. In some embodiments, the child subject may be between 6 and 22 months old. In some embodiments, the child subject may be between 6 and 24 months old. In some embodiments, the child subject was born at full term. In some embodiments, the child subject was born prematurely.

[0065] In some embodiments, the target age group is 6 months to 21 years old. In some embodiments, the target age group is under 21 years old. In some embodiments, the target age group is 10 to 21 years old. In some embodiments, the target age group is 5 to 10 years old. In some embodiments, the target age group is 12 months to 5 years old. In some embodiments, the target age group may be at least 6 months old. In some embodiments, the target age group is 6 months to 36 months old. In certain embodiments, the target age group is 6 months to less than 24 months old. In some embodiments, the target age group is 6 months to 18 months old. In some embodiments, the target age group is 6 months to 22 months old. In some embodiments, the child subject is 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, or 36 months old. In some embodiments, the child subject is 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, or 21 years old. In some embodiments, the child subject is born at full term. In some embodiments, the child subject is born prematurely. In some embodiments, the child subject has been previously infected with RSV. In some embodiments, the child subject has never been infected with RSV.

[0066] In some embodiments, when used in any of the methods described herein, the effective amount of RSV is approximately 5.4 log per dose. 10 Contains plaque-forming units (PFUs). In some embodiments, when used in any of the methods described herein, the effective amount of RSV is approximately 5.6 log per dose. 10 Contains plaque-forming units (PFUs). In some embodiments, when used in any of the methods described herein, the effective amount of RSV is approximately 6.2 log per dose. 10It contains plaque-forming units (PFU). In some embodiments, in use in any of the methods described herein, an effective amount of RSV is about 6.4 log 10 It contains plaque-forming units (PFU). In some embodiments, in use in any of the methods described herein, an effective amount of RSV is about 7.0 log 10 It contains plaque-forming units (PFU). In certain embodiments, in use in any of the methods described herein, an effective amount of RSV is about 5.4 log 10 PFU to 7.0 log 10 It contains PFU. In certain embodiments, in use in any of the methods described herein, an effective amount of RSV is about 5.6 log 10 PFU to 6.2 log 10 It contains PFU. In certain embodiments, in use in any of the methods described herein, an effective amount of RSV is about 5.6 log 10 PFU to 6.4 log 10 It contains PFU. In certain embodiments, in use in any of the methods described herein, an effective amount of RSV is about 5 log 10 PFU, 5.1 log 10 PFU, 5.2 log 10 PFU, 5.3 log 10 PFU, 5.4 log 10 PFU, 5.5 log 10 PFU, 5.6 log 10 PFU, 5.7 log 10 PFU, 5.8 log 10 PFU, 5.9 log 10 PFU, 6 log 10 PFU, 6.1 log 10 PFU, 6.2 log 10 PFU, 6.3 log 10 PFU, 6.4 log 10 PFU, 6.5 log 10 PFU, 6.6 log 10 PFU, 6.7 log 10 PFU, 6.8 log 10 PFU, 6.9 log10 PFU, 7 log 10 PFU, 7.1 log 10 PFU, 7.2 log 10 PFU, 7.3 log 10 PFU, 7.4 log 10 PFU, 7.5 log 10 PFU, 7.6 log 10 PFU, 7.7 log 10 PFU, 7.8 log 10 PFU, 7.9 log 10 PFU, 8 log 10 PFU, 8.1 log 10 PFU, 8.2 log 10 PFU, 8.3 log 10 PFU, 8.4 log 10 PFU, 8.5 log 10 PFU, 8.6 log 10 PFU, 8.7 log 10 PFU, 8.8 log 10 PFU, 8.9 log 10 PFU, and / or 9 log 10 comprises PFU. In certain embodiments, in use in any of the methods described herein, an effective amount of RSV is about 5 log 10 PFU to 9 log 10 PFU. In some embodiments, in use in any of the methods described herein, an effective amount of RSV is about 5 log 10 , 6 log 10 , 7 log 10 , 8 log 10 or 9 log 10 PFU. In some embodiments, in use in any of the methods described herein, an effective amount of RSV is about 5 log 10 to about 9 log 10 PFU.

[0067] In some embodiments, the RSV vaccine is delivered intranasally in a spray dose. In some embodiments, the RSV vaccine is delivered intranasally using an intranasal spray delivery device. In some embodiments, approximately half the dose is delivered to each nostril. In some embodiments, the RSV vaccine is delivered intranasally such that the entire dose is delivered to one nostril. In some embodiments, the RSV vaccine is delivered intranasally by delivering half the dose to one nostril and the other half dose to the same nostril sequentially or at the same time. In some embodiments, the RSV vaccine is delivered intranasally by delivering uneven doses to one or both nostrils. In some embodiments, the RSV vaccine is delivered intranasally by delivering three-quarters of the dose to one nostril and one-quarter of the dose to the other nostril or the same nostril. In some embodiments, the RSV vaccine is delivered into the nasal cavity by delivering 1 / 10, 1 / 9, 1 / 8, 1 / 7, 1 / 6, 1 / 5, 1 / 4, 1 / 3, 1 / 2, or the whole dose to one nostril and 9 / 10, 8 / 9, 7 / 8, 5 / 6, 4 / 5, 3 / 4, 2 / 3, or 1 / 2 of the other nostril or the same nostril.

[0068] In some embodiments, the RSV vaccine is delivered intranasally in a liquid formulation. In some embodiments, the RSV vaccine dose is delivered intranasally in a volume of about 0.2 mL. In some embodiments, the 0.2 mL dose is delivered intranasally such that about 0.1 mL is delivered to each nostril. In some embodiments, the RSV vaccine dose is delivered intranasally using an intranasal spray delivery device in a volume of about 0.1 mL, 0.2 mL, 0.3 mL, 0.4 mL, 0.5 mL, 0.6 mL, 0.7 mL, 0.8 mL, 0.9 mL, or 1.0 mL. As described above, the dose may be divided evenly between two nostrils, substantially evenly between two nostrils, unevenly between two nostrils, or all may be delivered to one nostril in one or more deliveries. In some embodiments, when used in any of the methods described herein, the RSV vaccine is delivered intranasally using an intranasal spray delivery device. In some embodiments, the intranasal spray delivery device may contain the RSV vaccine in a pre-filled outer tube.

[0069] In some embodiments, a method is provided for conferring immunity to respiratory syncytial virus (RSV) infection to a subject, comprising administering a first dose of RSV vaccine and administering a second dose of RSV vaccine. In some embodiments, the method for conferring immunity to RSV infection to a subject may include administering one or more doses using an intranasal spray delivery device.

[0070] In some embodiments, a method is provided for conferring immunity to RSV infection to a subject, comprising: optionally administering a first dose of an RSV vaccine containing attenuated live RSV using an intranasal spray delivery device; and optionally administering a second dose of the RSV vaccine using an intranasal spray delivery device.

[0071] In some embodiments, a method is provided for preventing or reducing the likelihood of a target RSV infection or for preventing or reducing at least one symptom of an RSV infection, comprising administering a first dose of an RSV vaccine and administering a second dose of an RSV vaccine. In some embodiments, a method is provided for preventing or reducing the likelihood of a target RSV infection or for preventing or reducing at least one symptom of an RSV infection, wherein one or more doses of an RSV vaccine are administered using an intranasal spray delivery device.

[0072] In some embodiments, a method for preventing or reducing the likelihood of a target RSV infection, or for preventing or reducing at least one symptom of an RSV infection, comprises, optionally, administering a certain dose of an RSV vaccine containing attenuated live RSV using an intranasal spray delivery device, and optionally administering a second dose of the RSV vaccine using an intranasal spray delivery device.

[0073] In some embodiments, when used in any of the methods described herein, the effective amount of RSV in the second dose is approximately 5.4 log per dose. 10 Contains PFU. In some embodiments, when used in any of the methods described herein, the effective amount of RSV in the second dose is approximately 5.6 log per dose. 10 Contains PFU. In some embodiments, when used in any of the methods described herein, the effective amount of RSV in the second dose is approximately 6.2 log per dose. 10 Contains PFU. In some embodiments, when used in any of the methods described herein, the effective amount of RSV in the second dose is approximately 6.4 log per dose. 10 Contains PFU. In some embodiments, when used in any of the methods described herein, the effective amount of RSV in the second dose is approximately 7.0 log per dose. 10 Contains PFU. In certain embodiments, when used in any of the methods described herein, the effective amount of RSV is approximately 5.4 log 10PFU~7.0log 10 Contains PFU. In certain embodiments, when used in any of the methods described herein, the effective amount of RSV in the second dose is approximately 5.4 log 10 PFU~7.0log 10 Contains PFU. In certain embodiments, when used in any of the methods described herein, the effective amount of RSV in the second dose is approximately 5.6 log per dose. 10 PFU~6.2log 10 Contains PFU. In some embodiments, when used in any of the methods described herein, the effective amount of RSV in the second dose is approximately 5.4 log per dose. 10 Contains PFU. In some embodiments, when used in any of the methods described herein, the effective amount of RSV in the second dose is approximately 5.6 log per dose. 10 Contains PFU. In some embodiments, when used in any of the methods described herein, the effective amount of RSV in the second dose is approximately 6.2 log per dose. 10 Contains PFU. In some embodiments, when used in any of the methods described herein, the effective amount of RSV in the second dose is approximately 6.4 log per dose. 10 Contains PFU. In some embodiments, when used in any of the methods described herein, the effective amount of RSV in the second dose is approximately 7.0 log per dose. 10 Contains PFU. In certain embodiments, when used in any of the methods described herein, the effective amount of RSV in the second dose is approximately 5.2 log10 PFU to 7.0 log10 PFU per dose. In certain embodiments, when used in any of the methods described herein, the effective amount of RSV in the second dose is approximately 5.6 log10 PFU to 6.4 log10 PFU per dose. In certain embodiments, when used in any of the methods described herein, the effective amount of RSV in the second dose is approximately 5 log 10 PFU, 5.1log 10 PFU, 5.2log 10PFU, 5.3log 10 PFU, 5.4log 10 PFU, 5.5log 10 PFU, 5.6log 10 PFU, 5.7log 10 PFU, 5.8log 10 PFU, 5.9log 10 PFU, 6log 10 PFU, 6.1log 10 PFU, 6.2log 10 PFU, 6.3log 10 PFU, 6.4log 10 PFU, 6.5log 10 PFU, 6.6log 10 PFU, 6.7log 10 PFU, 6.8log 10 PFU, 6.9log 10 PFU, 7Log 10 PFU, 7.1log 10 PFU, 7.2log 10 PFU, 7.3log 10 PFU, 7.4log 10 PFU, 7.5log 10 PFU, 7.6log 10 PFU, 7.7log 10 PFU, 7.8log 10 PFU, 7.9log 10 PFU, 8log 10 PFU, 8.1log 10 PFU, 8.2log 10 PFU, 8.3log 10 PFU, 8.4log 10 PFU, 8.5log 10 PFU, 8.6log 10 PFU, 8.7log 10 PFU, 8.8log 10 PFU, 8.9log 10 PFU and / or 9log 10 Contains PFU. In some embodiments, when used in any of the methods described herein, the effective amount of RSV in the second dose is about 5 log per dose. 10 ~approximately 9 log 10Contains PFU. In some embodiments, the effective amount of RSV in the second dose is about 5 log per dose. 10 Approximately 5.4 log 10 Approximately 5.6 log 10 , approximately 6 log 10 Approximately 6.2 log 10 Approximately 6.4 log 10 Approximately 7 log 10 Approximately 8 log 10 , or approximately 9 log 10 Contains PFU. In some embodiments, the first and second doses of the RSV vaccine are the same. In some embodiments, the first and second doses of the RSV vaccine administered are different. In some embodiments, the effective amount of RSV in the first and second doses is approximately 5.4 log per dose. 10 Contains PFU. In some embodiments, the effective amount of RSV in the first and second doses is approximately 5.6 log per dose. 10 Contains PFU. In some embodiments, the effective amount of RSV in the first and second doses is approximately 6.2 log per dose. 10 Contains PFU. In some embodiments, the effective amount of RSV in the first and second doses is approximately 6.4 log per dose. 10 Contains PFU. In some embodiments, the effective amount of RSV in the first and second doses is approximately 7.0 log per dose. 10 Contains PFU. In some embodiments, the effective amount of RSV in the first and second doses is about 5 log per dose. 10 ~approximately 9 log 10 Contains PFU. In some embodiments, the effective amount of RSV in the first dose is approximately 5.4 log per dose. 10 The second dose, including PFU, is approximately 5.6 log per dose. 10 Contains PFU. In some embodiments, the effective amount of RSV in the first dose is approximately 5.4 log per dose. 10 The second dose, including PFU, is approximately 6.2 log per dose. 10 Contains PFU. In some embodiments, the effective amount of RSV in the first dose is approximately 5.4 log per dose.10 The second dose, including PFU, is approximately 6.4 log per dose. 10 Contains PFU. In some embodiments, the effective amount of RSV in the first dose is approximately 5.4 log per dose. 10 The second dose, including PFU, is approximately 6.4 log per dose. 10 Contains PFU. In some embodiments, the effective amount of RSV in the first dose is approximately 5.4 log per dose. 10 The second dose, including PFU, is approximately 7.0 log per dose. 10 Contains PFU. In some embodiments, the effective amount of RSV in the first dose is approximately 5.6 log per dose. 10 The second dose, including PFU, is approximately 5.2 log per dose. 10 Contains PFU. In some embodiments, the effective amount of RSV in the first dose is approximately 5.6 log per dose. 10 The second dose, including PFU, is approximately 6.2 log per dose. 10 Contains PFU. In some embodiments, the effective amount of RSV in the first dose is approximately 5.6 log per dose. 10 The second dose, including PFU, is approximately 6.4 log per dose. 10 Contains PFU. In some embodiments, the effective amount of RSV in the first dose is approximately 5.6 log per dose. 10 The second dose, including PFU, is approximately 7.0 log per dose. 10 Contains PFU. In some embodiments, the effective amount of RSV in the first dose is approximately 6.2 log per dose. 10 The second dose, including PFU, is approximately 5.4 log per dose. 10 Contains PFU. In some embodiments, the effective amount of RSV in the first dose is approximately 6.2 log per dose. 10 The second dose, including PFU, is approximately 5.6 log per dose. 10 Contains PFU. In some embodiments, the effective amount of RSV in the first dose is approximately 6.2 log per dose. 10 The second dose, including PFU, is approximately 6.4 log per dose. 10Contains PFU. In some embodiments, the effective amount of RSV in the first dose is approximately 6.2 log per dose. 10 The second dose, including PFU, is approximately 7.0 log per dose. 10 Contains PFU. In some embodiments, the effective amount of RSV in the first dose is approximately 6.4 log per dose. 10 The second dose, including PFU, is approximately 5.4 log per dose. 10 Contains PFU. In some embodiments, the effective amount of RSV in the first dose is approximately 6.4 log per dose. 10 The second dose, including PFU, is approximately 5.6 log per dose. 10 Contains PFU. In some embodiments, the effective amount of RSV in the first dose is approximately 6.4 log per dose. 10 The second dose, including PFU, is approximately 6.2 log per dose. 10 Contains PFU. In some embodiments, the effective amount of RSV in the first dose is approximately 6.4 log per dose. 10 The second dose, including PFU, is approximately 7.0 log per dose. 10 Contains PFU. In some embodiments, the effective amount of RSV in the first dose is approximately 7.0 log per dose. 10 The second dose, including PFU, is approximately 5.4 log per dose. 10 Contains PFU. In some embodiments, the effective amount of RSV in the first dose is approximately 7.0 log per dose. 10 The second dose, including PFU, is approximately 5.6 log per dose. 10 Contains PFU. In some embodiments, the effective amount of RSV in the first dose is approximately 7.0 log per dose. 10 The second dose, including PFU, is approximately 6.2 log per dose. 10 Contains PFU. In some embodiments, the effective amount of RSV in the first dose is approximately 7.0 log per dose. 10 The second dose, including PFU, is approximately 6.4 log per dose. 10 Contains PFU. In some embodiments, the effective amount of RSV in the first dose is about 5 log per dose. 10Approximately 5.4 log 10 Approximately 5.6 log 10 , approximately 6 log 10 Approximately 6.2 log 10 Approximately 6.4 log 10 Approximately 7 log 10 Approximately 8 log 10 Or approximately 9log 10 The second dose contains PFU, and the second dose is approximately 5 log per dose. 10 Approximately 5.2 log 10 Approximately 5.6 log 10 , approximately 6 log 10 ,about 6.2log 10 Approximately 6.4 log 10 Approximately 7 log 10 Approximately 8 log 10 , or approximately 9 log 10 Includes PFU.

[0074] In some embodiments, the subjects described herein may be administered single or multiple doses of attenuated live RSV vaccine. Multiple doses (e.g., two, three, four or more doses) may be used in primary and / or booster immunization schedules. Multiple doses are typically administered at least one week apart (e.g., about two, three, four, six, eight, twelve, or sixteen weeks). In some embodiments, the RSV vaccine is administered in a single dose. In some embodiments, a second dose of the RSV vaccine is administered one or more times at an optional interval of about two, three, four, six, eight, twelve, or sixteen weeks, or at any other appropriate interval. In some embodiments, the second dose of the RSV vaccine is administered about seven to nine weeks after the first dose. In some embodiments, the second dose is administered approximately 40–50, 45–55, 55–60, 52–60, or 60–65 days after the first dose. In some embodiments, the two doses are administered approximately 56 days (8 weeks) apart. In some embodiments, the two doses are administered at least 56 days apart. In some embodiments, one or more doses of the attenuated live RSV vaccine may be administered using an intranasal spray delivery device.

[0075] In some embodiments, administration of the RSV vaccine reduces the incidence of RSV confirmed by testing. In some embodiments, administration of the RSV vaccine reduces at least one symptom of the RSV infection in question, where the symptom is selected from upper and / or lower respiratory tract RSV infection, onset or development of otitis media or related respiratory conditions, progression from upper respiratory tract RSV infection to lower respiratory tract RSV infection, or progression to otitis media or related respiratory conditions. In some embodiments, administration of the RSV vaccine reduces at least one symptom of the RSV infection, where the symptom is selected from asthma, wheezing, or a combination thereof.

[0076] In some embodiments, a method is provided for conferring immunity to respiratory syncytial virus (RSV) infection to a subject, comprising administering a first dose of RSV vaccine using an intranasal spray delivery device, wherein the intranasal spray delivery device comprises a spray nozzle for spraying the RSV vaccine. In some embodiments, the spray plume from the spray nozzle may be directed in the nasal cavity towards the uppermost part of the nasal passages. In some embodiments, a method is provided for preventing or reducing the likelihood of RSV infection in a pediatric subject, or for preventing or reducing at least one symptom of RSV infection, comprising administering a certain dose of RSV vaccine using an intranasal spray delivery device, wherein the intranasal spray delivery device comprises a spray nozzle for spraying the RSV vaccine. In some embodiments, the intranasal spray delivery device comprises an outer cylinder operably connected to the spray nozzle and a plunger movable within the outer cylinder for advancing the RSV vaccine through the spray nozzle. In some embodiments, the intranasal spray delivery device further includes a dose divider for dividing the dose of RSV vaccine into two or more deliveries. In some embodiments, the dose divider can divide the dose of the RSV vaccine into approximately half the volume to be delivered to the subject. In some embodiments, the dose divider is used to deliver half the dose to each nostril of the subject.

[0077] In some embodiments, the intranasal spray delivery device has an average droplet diameter D of 10-120 μm. v50 In some embodiments, the intranasal spray delivery device has an average droplet diameter D of approximately 10-120 μm, approximately 20-120 μm, approximately 30-120 μm, approximately 40-120 μm, approximately 50-110 μm, approximately 60-110 μm, approximately 70-110 μm, or approximately 80-110 μm. v50 The device delivers the following. In some embodiments, the intranasal spray delivery device delivers an average droplet diameter Dv50 of at least 100 μm, at least 110 μm, or at least 120 μm. In some embodiments, the intranasal spray delivery device delivers an average droplet diameter Dv50 of at least 30 μm, at least 50 μm, at least 70 μm, at least 80 μm, or at least 110 μm. In some embodiments, the intranasal spray delivery device delivers an average shot weight of about 30 mg to about 200 mg, about 50 mg to about 175 mg, about 70 mg to about 160 mg, about 80 mg to about 150 mg, 95 mg to about 135 mg, about 100 mg to about 130 mg, about 100 mg to about 130 mg, or about 105 mg to about 130 mg. In some embodiments, the intranasal spray delivery device delivers average shot volumes of approximately 25 μL to 200 μL, 50 μL to 175 μL, 60 μL to 150 μL, 75 μL to 130 μL, 85 μL to 120 μL, 90 μL to 115 μL, or 95 μL to 115 μL.

[0078] In some embodiments, the use of an intranasal spray delivery device described herein is provided for administering a certain dose of an RSV vaccine to a target, wherein the RSV vaccine comprises an effective amount of attenuated live RSV. In some embodiments, this use comprises attenuated live RSV ΔNS2 / Δ1313 / I1314L.

[0079] In some embodiments, the use of an RSV vaccine is provided for the manufacture of a pharmaceutical product that prevents or reduces the likelihood of RSV virus infection in a subject, and this RSV vaccine contains an effective amount of attenuated live RSV. In some embodiments, this use includes RSV ΔNS2 / Δ1313 / I1314L.

[0080] III. RSV vaccine In some embodiments, the RSV vaccine may include a live attenuated vaccine. In one embodiment, the RSV vaccine described as “RSVΔNS2 / Δ1313 / I1314L vaccine” is a live attenuated vaccine (ΔNS2) based on the deletion of the gene encoding the RSV interferon / apoptotic antagonist NS2 protein. Deleting the NS2 gene can attenuate the virus and enhance its immunogenicity. The RSVΔNS2 / Δ1313 / I1314L vaccine also includes genetically stabilized attenuation mutations and temperature-sensitive mutations in the L protein (codon deletion Δ1313, and a missense mutation I1314L that prevents a deattenuation mutation that would normally occur at position 1314), and as a result, RSVΔNS2 / Δ1313 / I1314L is temperature-sensitive, with a virus replication cutoff temperature of 38°C to 39°C (100.4°F-102.2°F).

[0081] The RSVΔNS2 / Δ1313 / I1314L vaccine is a recombinant infectious respiratory syncytial virus containing a large polymerase protein (L), a phosphoprotein (P), a nucleocapsid protein (N), an M2-1 protein non-structural protein 1 (NS1), a glycoprotein (G), a fusion protein (F), a matrix protein (M), an M2-2 protein, and a small hydrophobic protein (SH). The genome or antigenome has a deletion of a codon encoding serine at position 1313 of the L protein, or the corresponding position, a mutation at amino acid sequence residue 1314 of the L protein, or the corresponding position, wherein the mutation at amino acid sequence residue 1314 of the L protein is an amino acid substitution from isoleucine to leucine, and leucine is a mutation encoded by a codon represented as CTG, and a deletion of the NS2 gene. The RSVΔNS2 / Δ1313 / I1314L vaccine and the method for producing this vaccine are described in International Publication No. 2013 / 154728 A1 (which is incorporated by reference in whole for all purposes).

[0082] IV. Intranasal Nebulization Delivery Device A. Equipment In some embodiments, an intranasal spray delivery device may be used for the delivery of the vaccine described herein. The intranasal spray delivery device may be any suitable device for atomizing the RSV attenuated live vaccine. In some embodiments, the delivery device has an average droplet diameter D of about 10 μm to 120 μm. v50 It may provide the following. In some embodiments, the delivery device is suitable for delivery to pediatric subjects. In certain embodiments, the delivery device is suitable for delivery to pediatric subjects aged 6 to 18 months. In various embodiments, the delivery device is suitable for delivery to pediatric subjects aged 6 months or more but less than 24 months. In some embodiments, the delivery device is suitable for delivery to pediatric subjects aged at least 6 months. In various embodiments, the delivery device may be configured to deliver two substantially equal doses, one dose to each nostril. In some embodiments, both doses are delivered sequentially or simultaneously.

[0083] As a non-limiting example, a suitable intranasal spray delivery device 10 is described. As shown in Figure 2, the intranasal spray delivery device 10 may include a barrel 4 for receiving the vaccine to be delivered to the subject. The delivery device 10 may also include a Luer lock 3 adapted to receive a vial access cannula 2 and / or atomizer 6. The delivery device may include a cap 1 for covering the vial access cannula 2. The delivery device 10 may also include a plunger 5 sized and shaped to fit just inside the barrel 4. The barrel 4 may also include a graduation line, as shown in Figure 4, to identify the volume inside the barrel 4 for delivering a certain amount of vaccine. As a non-limiting example, the graduation line may be a 0.05 mL graduation line, a 0.1 mL graduation line, a 0.2 mL graduation line, or other graduation lines, depending on the dose to be delivered and whether the administration is to be done through one nostril or both nostrils. In some embodiments, the barrel 4 may be a 1 mL syringe. In non-limiting examples, the syringe may be a 1 mL Luer-lock disposable plastic syringe, such as B. Braun Omnifix®-F. In some embodiments, the outer barrel 4 may be a smaller or larger volume syringe. The vial access cannula 2 may be used to withdraw the vaccine from the vial at the medical center for delivery to the subject. In some embodiments, the vial access cannula 2 may be a semi-blunt or sharp aspiration needle. In non-limiting examples, the semi-blunt aspiration needle may be 18G × 40 mm (B. Braun Sterican® MIX). Once the outer barrel 4 is filled with the appropriate vaccine dose, the vial access cannula 2 may be removed, and the atomizer 6 may be connected to the outer barrel 4 via the Luer lock 3. The atomizer 6 may be primed before the vaccine dose is administered intranasally. The atomizer 6 is roughly conical in shape, with a wide base that tapers towards the end so that the end can be inserted into the nostril and a spray plume can be released from the atomizer 6, as described below. In some embodiments, the outer cylinder 4 may be pre-filled with the vaccine dose to be delivered.

[0084] In some embodiments, the intranasal delivery device 10 may have a typical droplet diameter of about 10 μm to 120 μm and a system dead space of about 0.1 mL to 0.2 mL. In some embodiments, the system dead space may be about 0.15 mL. The atomizer 6 may have a tip diameter of about 3.5 mm to 5 mm to facilitate delivery into the nasal cavity. In some embodiments, the tip diameter may be about 4 mm to 4.5 mm, or about 4.3 mm. As a non-limiting example, the Teleflex MAD130 Nasal® device system or the Teleflex Vaxinator® (VAX300) device may be used for intranasal delivery of the vaccine to the subject. In some embodiments, the atomizer 6 may be an Aptar or LuerVax® device.

[0085] B. Dose divider In some embodiments, the intranasal spray delivery device 10 of Figure 2 may be provided with a dose divider 12 (see Figures 3 and 4). The dose divider 12 can be used to divide the vaccine dose supplied to the intranasal spray delivery device 10. In some embodiments, the dose divider 12 may be used to divide the vaccine dose into two substantially equal half doses (e.g., a first half and a second half), so that half doses are delivered separately to each nostril, or two half doses to the same nostril. Other dose divisions are also possible depending on the height of the dose divider. As shown in Figures 3 and 4, the dose divider 12 may include a first section 14 having a height corresponding to the partial dose to be delivered to the first nostril. The first section 14 may also include a notch 16 of a size and shape corresponding to the size and shape of the plunger 5. The dose divider 12 may also include a second portion 18 with two projections 20 that can be used to widen the opening 22 of the first portion 14 so that the notch 16 can be positioned relative to the plunger 5 of the delivery device 10. Releasing the two projections 20 closes the first portion 14 on the plunger 5, so that the volume of the first partial dose delivered to the first nostril can be controlled. The dose divider 12 can be removed from the plunger 5 for delivery of a second partial dose to the target second nostril. In non-limiting examples, the dose divider (such as the dose divider 12) can be used to deliver volumes of approximately 0.01 mL, 0.02 mL, 0.05 mL, 0.075 mL, 0.1 mL, 0.2 mL, 0.3 mL, 0.4 mL, 0.5 mL, 0.6 mL, 0.7 mL, 0.8 mL, 0.9 mL, or 1.0 mL per nostril. Other volumes may also be used. In some embodiments, the dose divider 12 can divide the dose into two nearly equal halves.

[0086] C. Dose delivery The vaccine is to be delivered intranasally to the subject using the delivery device 10. In some embodiments, the dose may be delivered in approximately half to each nostril, a larger volume to the first nostril and a smaller volume to the second nostril, or in two doses of the same or different volumes to the same nostril. Dose delivery is described herein as the delivery of approximately half a volume to each nostril, but is not limited thereto. The total dose to be delivered to the subject can be placed in the delivery device 10 by withdrawing the vaccine from a container (e.g., a vial; not shown) containing one or more doses of vaccine using the vial access cannula 2. Once the total dose is in the outer cylinder 4 of the delivery device 10, the vial access cannula 2 can be removed from the Luer lock 3, and the atomizer 6 can be coupled or connected to the Luer lock 3. Furthermore, the atomizer 6 can be primed, and the dose divider 12 can be connected to the plunger 5 as described above. By inserting the atomizer 6 into the first nostril and advancing the plunger 5 a first distance within the outer cylinder 4, a first half volume can be dispensed from the atomizer 6, atomizing the vaccine and forming a spray plume. The spray plume may contain a misty droplet size ranging from approximately 10 μm to approximately 120 μm. The tip region of the atomizer 6 may be substantially conical. The spray plume may generally enter the nasal cavity through the nasal valves, including the turbinate region (including the inferior, middle, and superior turbinate regions), and proceed towards the uppermost part of the nasal passage. By advancing the plunger 5 a first distance within the outer cylinder 4 until its end contacts the dose divider 12, and then stopping the advance, a first half volume can be delivered to the first nostril.

[0087] After the first half dose has been delivered to the first nostril, the dose divider 12 can be removed from the plunger 5. Next, the atomizer 6 can be inserted into the second nostril, and the second half dose can be delivered to the second nostril by advancing the plunger 5 a second distance within the outer cylinder 4. When the plunger 5 contacts the end of the outer cylinder 4, the second half dose may be delivered by advancing the second distance. [Examples]

[0088] The following examples are provided to illustrate specific embodiments of the disclosed, and these examples should not be construed as limiting the scope of the disclosure in any way.

[0089] Example 1. Safety, immunogenicity, infectivity, and dose-determining study of RSV attenuated live vaccine for clinical trials in infants and toddlers. executive summary Investigational drug Recombinant attenuated live respiratory syncytial virus (RSV) RSVΔNS2 / Δ1313 / I1314L (Sanofi) vaccine.

[0090] active substance Attenuated RSV (RSVΔNS2 / Δ1313 / I1314L(Sanofi)) with (i) a 523 nucleotide (nt) deletion in the NS2 gene (ΔNS2), (ii) an amino acid deletion in the L protein (Δ1313; deletion of S1313), and (iii) a genetically stabilizing mutation in the L gene (I1314L).

[0091] Research facilities This is a multicenter, multinational study involving approximately 30 institutions in the United States, 2 institutions in Canada, 6 institutions in Latin America (Argentina, Chile, and Honduras), and 2 institutions in South Africa.

[0092] Phase I / II trials A phase I / II, randomized, observer-blinded, placebo-controlled, multicenter dose-finding study was conducted to evaluate the safety, immunogenicity, infectivity, and vaccine virus shedding after one or two doses of attenuated live RSV ΔNS2 / Δ1313 / I1314L (Sanofi) vaccine administered via intranasal spray delivery devices to infants and toddlers aged 6 to 18 months (cohorts 1–4) in the United States, Canada, Latin America (Argentina, Chile, and Honduras), and South Africa. An exemplary study protocol is shown in Figure 1, where the dose may be any dose described in Example 1.

[0093] Vaccination: A total of 300 infants and toddlers aged 6–18 months were enrolled in one of four cohorts, and then randomized within each cohort to receive intranasal administration of their assigned investigational drug using an intranasal spray delivery device, as follows:

[0094] In a cohort of 1-40 infants and toddlers, the ratio of RSVΔNS2 / Δ1313 / I1314L(Sanofi)5.6log was 1:1. 10 They received a single dose of either PFU (low dose) or placebo (the same formulation buffer as the RSVΔNS2 / Δ1313 / I1314L (Sanofi) vaccine).

[0095] In a cohort of 2-40 infants and toddlers, the ratio of RSVΔNS2 / Δ1313 / I1314L(Sanofi)5.6log was 1:1. 10 The patient received two doses of either PFU (low dose) or placebo.

[0096] In a cohort of 3-40 infants and toddlers, the ratio of RSVΔNS2 / Δ1313 / I1314L(Sanofi)6.2log was 1:1. 10 The patient received a single dose of either PFU (high dose) or placebo.

[0097] In a cohort of 4-180 infants and toddlers, the ratio of RSVΔNS2 / Δ1313 / I1314L(Sanofi)5.6log was 1:1:1. 10 PFU (low dose), RSVΔNS2 / Δ1313 / I1314L (Sanofi)6.2log 10 The patient received two doses of either PFU (high dose) or placebo.

[0098] [Table 1]

[0099] [Table 2]

[0100] Table 3

[0101] Table 4

[0102] Table 5

[0103] Table 6

[0104] Table 7

[0105] Table 8

[0106] Table 9

[0107] Table 10

[0108] Table 11

[0109] Table 12

[0110] Table 13

[0111] [Table 14]

[0112] [Table 15]

[0113] List of Abbreviations Adverse events (AEs) AESI (Adverse Events of Particular Note) AR adverse reactions CDC (Centers for Disease Control and Prevention) Data Management in Clinical Research (CDM) CI confidence interval COVID-19 (Coronavirus Disease) CQA (Clinical Quality Management) CRA (Clinical Research Associate) CRB (Electronic) Case Report Form [All case reports for the subject] CRF (Electronic) Case Report Form D Number of days DAIDS (Division of AIDS) DC Daily Card eDC Electronic Daily Card EDC (Electronic Data Collection) System EENT Eye / Ear, Nose and Throat ELISA enzyme-linked immunosorbent assay ESDR Initial Safety Data Review FAS's largest analysis population FDA (Food and Drug Administration) FVFS First visit date of the first subject FVLS final subject's first visit date Gcc G (glycoprotein) central conservation region GCI Global Clinical Immunology GCP (Good Clinical Practice) - Standards for Conducting Clinical Trials of Pharmaceuticals GMT Geometric Mean Titer GMTR (Geometric Mean Potency Ratio) GPV Global Pharmacovigilance HIV (Human Immunodeficiency Virus) IATA (International Air Transport Association) ICF Informed Consent Form ICH (International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use) IDMC Independent Data Monitoring Committee IEC Independent Ethics Committee Ig immunoglobulin IME Important Medical Events IND (Investigational Drug) - Application to initiate a clinical trial for a new drug IRB (Institutional Review Board) IRT (Interactive Response Technology) Last visit date of the last LCLS subject LID (Laboratory of Infectious Diseases) LLOQ Lower limit of quantitation LLT lower word LRI lower respiratory tract disease MA Memory Aid MAAE: Adverse events that led to a visit to a medical institution. MAARI: Acute respiratory illness leading to medical consultation. MAD mucosal spray device MAALRI Acute lower respiratory tract disease requiring medical attention MedDRA International Medical Dictionary for Regulatory Activities mL (milliliter) MN Micro-neutralization nAb Neutralizing antibody NC negative control NIAID (National Institute of Allergy and Infectious Disease) NIH National Institutes of Health NS nasal swab NSAIDs (non-steroidal anti-inflammatory drugs) PFU plaque formation unit PC positive control PCR (polymerase chain reaction) PSB Product Safety Board POC (Point of Care) PPAS protocol conformance analysis target population PT basic term RCDC inverse cumulative distribution curve RSV (Respiratory Syncytial Virus) RSV (Recombinant Attenuated Live Respiratory Syncytial Virus) ΔNS2 / Δ1313 / I1314L ΔNS2 / Δ1313 / I1314L(NIH) or ΔNS2 / Δ1313 / I1314L(Sanofi) vaccine RSV-LRI RSV-related lower respiratory tract diseases RSV MAARI: Acute respiratory illness leading to visit to a medical institution related to RSV. RSV MAALRI: Acute lower respiratory tract disease leading to a visit to a medical institution related to RSV. Medical Officer in Charge of RMO RT-PCR (Reverse Transcriptase Polymerase Chain Reaction) QRT-PCR (Quantitative Real-Time Reverse Transcriptase Polymerase Chain Reaction) rRT-PCR (Real-time Reverse Transcriptase Polymerase Chain Reaction) SAE (Serious Adverse Event) SafAS Safety Analysis Target Population SMT Safety Management Team SOC major classification by organ TBD undecided TMF Clinical Trial Master File ULOQ Upper limit of quantification URI Upper Respiratory Tract Diseases US United States VAC (Vaccine Adjudication Committee) VTM Virus Transport Medium WHO (World Health Organization) wt wild type

[0114] detail: Theoretical basis of this research Prior to the RSVΔNS2 / Δ1313 / I1314L vaccine provided herein, three RSV vaccine viruses with NS2 gene deletions (rA2cpΔNS2, rA2cp248 / 404ΔNS2, and rA2cp530 / 1009ΔNS2) had been evaluated in clinical trials (Wright et al., 2006, J. Infect Dis., 193(4):573-81). The rA2cpΔNS2 candidate was over-attenuated for adults but under-attenuated for use in young children, while both rA2cp248 / 404ΔNS2 and rA2cp530 / 1009ΔNS2 were over-attenuated and immunogenic in seronegative children. Based on these results, RSVΔNS2 / Δ1313 / I1314L (NIH) was developed. In a recent Phase Ia study sponsored by the National Institutes of Health (NIH) in RSV seronegative children aged 6–24 months (n=20), (Karron et al., 2020, J Infect Dis.;222(1):82-91), 10 6At PFU doses, RSV ΔNS2 / Δ1313 / I1314L (NIH) was safe, exhibited good infectivity (100% of vaccinated subjects were infected), and was immunogenic (neutralizing antibody titers increased more than fourfold in 80% of subjects), priming a strong prior response to wild-type (wt) RSV infection in post-epidemic surveillance.

[0115] Research purpose Main purpose Regardless of baseline serological status, in all infants and toddlers, the safety profile of each dose of RSVΔNS2 / Δ1313 / I1314L (Sanofi) should be assessed after each administration, regardless of whether the drug is administered using an intranasal spray delivery device.

[0116] In subjects uninfected with RSV, characterize the RSV A serum neutralizing antibody response to the investigational drug in each vaccine group: after vaccination 1 (D56) for cohorts 1, 2, 3, and 4, and after vaccination 2 (D84) for cohorts 2 and 4.

[0117] Secondary purpose For cohorts 1, 2, 3, and 4, the amount of vaccine virus shed by each participant, measured by quantitative reverse transcriptase polymerase chain reaction (RT-PCR), should be quantified according to baseline serological status on D7, and for cohorts 2 and 4, on D63.

[0118] For cohorts 1, 2, 3, and 4, the proportion of vaccinated infants and toddlers infected with the vaccine virus in each vaccine group should be determined according to baseline serological status after vaccination 1 (D56), and for cohorts 2 and 4, after vaccination 2 (D84). (Infection is defined as detection of the vaccine by polymerase chain reaction (PCR) in nasal swab samples and / or a four-fold or greater increase in RSV A serum neutralizing antibody titer or RSV serum anti-F IgG antibody titer).

[0119] In subjects with a history of RSV infection, for cohorts 1, 2, 3, and 4, after vaccination 1 (D56), and for cohorts 2 and 4, after vaccination 2 (D84), characterize the RSV A serum neutralizing antibody response to the investigational drug in each vaccine group.

[0120] For cohorts 1, 2, 3, and 4, after vaccination 1 (D56), and for cohorts 2 and 4, after vaccination 2 (D84), characterize the RSV serum anti-F IgG antibody response to the investigational drug in each vaccine group by baseline serological status.

[0121] After the RSV surveillance epidemic period or at least 5 months after the last vaccine administration, characterize the RSV serum antibody response (RSV A neutralization and anti-RSV F IgG) to the investigational drug in each vaccine group by baseline serological status.

[0122] Exploratory objectives Exploratory safety objectives For each dose of RSV, determine the safety profile after each administration by baseline serological status for each administration.

[0123] Exploratory immunogenicity objectives: · For cohorts 1, 2, 3, and 4, after vaccination 1 (D56), and for cohorts 2 and 4, after vaccination 2 (D84), characterize the RSV A serum neutralizing antibody response to the investigational drug converted to IU / mL values in each vaccine group by baseline serological status. · After the RSV epidemic period or at least 5 months after the last vaccine administration, characterize the RSV A serum neutralizing antibody response to the investigational drug converted to IU / mL values by baseline serological status. · For cohorts 1, 2, 3, and 4, after vaccination 1 (D56), and for cohorts 2 and 4, after vaccination 2 (D84), characterize the RSV B serum neutralizing antibody response to the investigational drug in each vaccine group by serum antibody status. · For cohorts 1, 2, 3, and 4, after vaccination 1 (D56), and for cohorts 2 and 4, after vaccination 2 (D84), characterize the RSV B serum neutralizing antibody responses to the clinical trial drug converted to IU / mL values by serum antibody status in each vaccine group. · After the RSV epidemic period or at least 5 months after the last vaccine dose, characterize the RSV B serum neutralizing antibody responses to the clinical trial drug in each vaccine group by serum antibody status. · After the RSV epidemic period or at least 5 months after the last vaccine dose, characterize the RSV B serum neutralizing antibody responses to the clinical trial drug converted to IU / mL values by serum antibody status. · For cohorts 1, 2, 3, and 4, after vaccination 1 (D56), and for cohorts 2 and 4, after vaccination 2 (D84), characterize the RSV A and RSV B serum anti-protein G central conserved region (Gcc) IgG antibody responses to the clinical trial drug in each vaccine group by baseline serological status. · After the RSV epidemic period or at least 5 months after the last vaccine dose, characterize the RSV A and RSV B serum anti-Gcc IgG antibody responses to the clinical trial drug in each vaccine group by serum antibody status. · For cohorts 1, 2, 3, and 4, after vaccination 1 (D56), and for cohorts 2 and 4, after vaccination 2 (D84), characterize the RSV serum anti-F IgA antibody responses by baseline serological status. · After the RSV epidemic period or at least 5 months after the last vaccine dose, characterize the RSV serum anti-F IgA antibody responses by baseline serological status.

[0124] Exploratory efficacy objectives To clarify the frequency and severity of RSV-related acute respiratory illness (RSV MAARI) and RSV-related acute lower respiratory tract illness (RSV MAALRI) that led to visits to medical facilities in all infants and toddlers in each vaccine group during the RSV epidemic period or at least 5 months after the final dose of the vaccine.

[0125] Key safety evaluation items: Regardless of baseline serological status, in all infants and toddlers, • In each case, the occurrence of systemic adverse events (AEs) was reported spontaneously within 30 minutes of vaccination. • For each vaccine, the occurrence of administration site reactions and systemic reactions (i.e., those listed in advance for the target DC / eDC and CRB) based on requested, involuntary reports within 28 days after each vaccination (i.e., during the acute phase). • In any case of vaccination, the occurrence of an adverse event (AE) reported spontaneously (reported voluntarily) within 28 days of the respective vaccination. • Any AESI (Anaesthesia-mediated Stress Syndrome) occurring within 28 days of vaccination for any type of vaccine. • Any MAAE (Mean Emergency Affected) occurring within 28 days of vaccination for any type of vaccine. • The occurrence of any type of SAE throughout this study. Other safety evaluation items will be recorded or created as described in the statistical analysis plan. Depending on the item, these may include nature (Medical Dictionary for Regulatory Activity (MedDRA) basic terminology), time of occurrence, duration, number of days, intensity, relationship with vaccine, treatment performed, whether the AE led to early termination of the study, severity, or outcome.

[0126] Key immunogenicity endpoints: For cohorts 1, 2, 3, and 4, RSV A serum neutralizing antibody titers were obtained up to D56 for RSV-uninfected subjects; for cohorts 2 and 4, RSV A serum neutralizing antibody titers were obtained up to D84.

[0127] For the sponsor's Phase I / II trial, data will be analyzed according to baseline serological status. Baseline serological status will be retrospectively determined from serum samples collected at baseline (V01). Participants will be classified as having a history of RSV infection or not based on the presence or absence of detectable RSV serum anti-F IgA antibodies. This biomarker was chosen because it is produced only in response to RSV infection and does not cross the placenta between mother and child.

[0128] Clinical trial implementation plan Description of the overall research design and plan Research design This is a Phase I / II, randomized, observer-blinded, placebo-controlled, multicenter, dose-finding study evaluating the safety, immunogenicity, infectivity, and vaccine virus shedding after one or two doses of attenuated live RSV ΔNS2 / Δ1313 / I1314L (Sanofi) vaccine administered via an intranasal spray delivery device to infants and toddlers aged 6 to 18 months (cohorts 1–4) in the United States, Canada, Latin America (Argentina, Chile, and Honduras), and South Africa.

[0129] Vaccination: A total of 300 infants and toddlers aged 6–18 months were enrolled or will be enrolled in one of four cohorts, and subsequently, within each cohort, were randomized or will be randomized to receive intranasal administration of their assigned investigational drug using an intranasal spray delivery device as follows: In a cohort of 1-40 infants and toddlers, a single dose of RSVΔNS2 / Δ1313 / I1314L(Sanofi) in a 1:1 ratio was administered to 5.6log. 10 Have you received, or will receive, PFU (low dose) or placebo (the same formulation buffer as the RSVΔNS2 / Δ1313 / I1314L (Sanofi) vaccine)? In a cohort of 2-40 infants and toddlers, RSVΔNS2 / Δ1313 / I1314L(Sanofi) was administered twice in a 1:1 ratio, resulting in a 5.6 log 10 Have you received or will receive PFU (low dose) or placebo? In a cohort of 3-40 infants and toddlers, a single dose of RSVΔNS2 / Δ1313 / I1314L(Sanofi) in a 1:1 ratio was administered to 6.2log. 10 Have you received or will receive PFU (high dose) or placebo? In a cohort of 4-180 infants and toddlers, RSV ΔNS2 / Δ1313 / I1314L(Sanofi) 5.6log was administered twice in a 1:1:1 ratio. 10 PFU (low dose), RSVΔNS2 / Δ1313 / I1314L (Sanofi)6.2log 10 They received either PFU (high dose) or a placebo.

[0130] Cohort 1 (Northern Hemisphere): 1:1 randomization, placebo-controlled, one dose of RSVΔNS2 / Δ1313 / I1314L(Sanofi) (5.6 log) administered on day 0 (D0) 10 The vaccine was administered as a single dose (0.2 mL total per dose) with n=20 participants per vaccine group. Registration began at approximately 15 sites in the United States. Vaccination of registered participants was completed at least 5 days before the start of the RSV season (the average RSV season in the Northern Hemisphere is 5 months, from November 1 to March 31). Cohort 1 did not reach its target of n=40 participants, and therefore no further enrollment was attempted in subsequent cohorts.

[0131] Cohort 2 (Southern Hemisphere): 1:1 randomization, placebo-controlled, one dose of RSVΔNS2 / Δ1313 / I1314L (Sanofi) at D0 and D56 (5.6 log 10The vaccine consisted of two doses (0.2 mL total per dose) of PFU, with n=20 participants per vaccine group. Enrollment began as early as November / December 2020 at approximately four sites in Latin America (Argentina and Chile). The first and second doses of the vaccine (D0 and D56, respectively) for enrolled participants were completed at least 5 days before the start of the RSV epidemic (the average 5-month RSV epidemic in the Southern Hemisphere runs from May 1 to September 30). If the recruitment of Cohort 1 did not reach the target of n=40 participants, no further enrollment was attempted in subsequent cohorts.

[0132] Cohort 3 (Northern Hemisphere): 1:1 randomization, placebo-controlled, D0 received one dose of RSVΔNS2 / Δ1313 / I1314L (Sanofi) (6.2 log 10 The vaccine consisted of a single dose (0.2 mL total per dose) of PFU, with n=20 participants per vaccine group. Enrollment began in April 2021 at approximately 30 sites in the United States. Vaccine administration to enrolled participants was completed by May 31, 2021. The recruitment for Cohort 3 did not reach the target of n=40, and no further enrollment of participants receiving a single dose or more was attempted for Cohort 4.

[0133] Cohort 4 (Northern and Southern Hemispheres): 1:1:1 randomized, placebo-controlled, two doses of RSVΔNS2 / Δ1313 / I1314L (Sanofi) were administered to D0 and D56 (5.6 log 10 PFU or 6.2log 10 The vaccine was administered in two doses (0.2 mL per dose in total), with n=60 for each vaccine group. Registration began as early as June 2021 at approximately 30 facilities in the United States, as early as May 2022 at approximately 2 facilities in Canada, as early as November 2021 at approximately 2 facilities in Chile, as early as April 2022 at approximately 2 facilities in Honduras, and as early as June 2022 at approximately 2 facilities in South Africa.

[0134] The first and second vaccine administrations for the enrolled subjects were completed at any time during the year, including the winter RSV epidemic season, regardless of whether the normal RSV epidemic seasonality had recovered after the disruption caused by the non-pharmaceutical interventions for COVID-19.

[0135] Blood sampling: All subjects screened for inclusion in cohorts 1, 2, 3, and 4 provided a blood sample for baseline RSV serological antibody testing at the time of enrollment (clinic visit 01).

[0136] All subjects in each vaccine group of cohorts 1, 2, 3, and 4 provided a blood sample for measuring post-vaccination serum antibody titers against RSV at the time of D56 clinic visit (before vaccination 2 for cohorts 2 and 4). All subjects in each vaccine group of cohorts 2 and 4 provided a blood sample for measuring serum antibodies against RSV after vaccination 2 at the time of D84 clinic visit (28 days after vaccination 2). All subjects in cohorts 1, 2, 3, and 4 provided a blood sample for measuring post-epidemic RSV antibody titers during the one-month period after the end of the RSV epidemic season or at least 5 months after the last vaccine administration, to determine whether a more than 4-fold increase in RSV antibody titers occurred during the RSV epidemic season, which indicates infection with wild-type RSV not detected by surveillance.

[0137] Nasal swab samples: For cohorts 1, 2, 3, and 4 at D7; and for cohorts 2 and 4 at D63, nasal swab samples were collected from all enrolled subjects for the following purposes: · For quantifying vaccine virus shedding in cohorts 1, 2, 3, and 4 at D7, and in cohorts 2 and 4 at D63. · Using the same nasal swab specimens, subjects were tested for illness and respiratory pathogens at the same time point (D7 for cohorts 1, 2, 3, and 4, and D63 for cohorts 2 and 4). Nasal swab specimens for the detection of RSV and respiratory pathogens were collected from subjects at the time of hospital visit due to illness, 48 ​​hours later, and at any other time point specified in the protocol of this study, including surveillance leading to visits to medical institutions during the RSV epidemic.

[0138] Collection of safety data: The acute phase of the first vaccine dose begins on day 0 after vaccination and ends at midnight on day 28. The acute phase of the second vaccine dose begins on day 56 after vaccination and ends at midnight on day 84. Any adverse reactions, AEs, AESIs, MAAEs, or SAEs that begin during the acute phase (i.e., within 28 days after vaccination) but are diagnosed by a healthcare professional more than 28 days later are still considered to have occurred during the acute phase.

[0139] For subjects who received one dose, the acute post-operative period begins at 0:01 AM on D29 and ends at 0:00 AM on D56. For subjects who received two doses, the first acute post-operative period begins at 0:01 AM on D29 and ends at 0:00 AM on D56, except when the second dose is exactly on D56, in which case it ends immediately before the second dose is administered. For subjects who received two doses, the second acute post-operative period begins at 0:01 AM on D85 and ends at 0:00 AM on D112.

[0140] All subjects were observed for 30 minutes after each vaccine administration, and any spontaneously reported systemic adverse events (AEs) occurring during that time were recorded in the case report form (CRB) as immediate, spontaneously reported systemic AEs.

[0141] For all subjects, we tracked involuntary, request-based reports of administration site and systemic reactions, spontaneously reported adverse events, adverse events of particular interest (AESIs), and adverse events requiring medical consultation (MAAEs) within 28 days after each vaccination. For serious adverse events (SAEs), we tracked them from vaccination until the end of study participation.

[0142] Parents / guardians / legal representatives of the subjects recorded information on daily cards (DCs) / electronic daily cards (eDCs), obtaining requested involuntary responses, spontaneously reported AEs, AESIs, and MAAEs from D0 to D28 for cohorts 1, 2, 3, and 4, and from D56 to D84 for cohorts 2 and 4. Parents / guardians / legal representatives notified the research site of any responses, AEs, and any symptoms suggestive of respiratory disease. The research site followed up with telephone interviews. eDCs also allowed for daily safety monitoring of study participants. In specific cases where eDCs could not be used, paper daily cards were used for daily safety monitoring. All requested involuntary responses were graded by the sponsor on an intensity scale, except for runny nose / rhinorrhea and nasal congestion or nasal blockage / nasal congestion, which were graded using the Division of AIDS (DAIDS) rating scale. Particularly noteworthy adverse events were graded using the DAIDS rating scale; however, wheezing was graded according to the Brighton Collaboration standards.

[0143] Based on previous clinical experience at the National Institutes of Health (NIH) using RSV attenuated live vaccine candidates and the sponsor's safety guidelines and standard practices for collecting, analyzing, and reporting safety data, the following predefined, requested, and involuntary reports were made during the acute phase of each vaccine administration: injection site reactions including runny nose and nasal congestion or nasal blockage / feeling of nasal congestion, and systemic reactions including fever, vomiting, abnormal crying, drowsiness, loss of appetite, and irritability.

[0144] During the acute phase of this study, the following AESIs were assessed: acute otitis media, upper respiratory tract disease (URI) including pharyngitis and cough without lower respiratory tract disease (LRI), lower respiratory tract disease (LRI) with strider syndrome, rales, tachypnea, acute wheezing, pneumonia, and laryngotracheobronchitis. As with all vaccines, immediate hypersensitivity reactions, including urticaria, anaphylaxis, or other immunoglobulin (Ig) E-mediated reactions, are possible. MAAEs were collected during the acute phase for all vaccinations using the same process as other AEs. SAEs were recorded throughout the subjects' participation in this study. The subjects' parents / guardians / legal representatives were required to immediately notify the facility of any possible SAEs at any time during the study. In addition, the subjects' parents / guardians / legal representatives recorded information on SAEs in their DC / eDC from D0 to D56 visits (Cohorts 1 and 3) and from D0 to D84 visits (Cohorts 2 and 4). The parents / guardians / decision-makers of the subjects received a Memory Aid (MA) and recorded the SAE from the D56 visit until the end of the study (Cohorts 1 and 3) and from the D84 visit until the end of the study (Cohorts 2 and 4). The completed DC / eDC or MA was reviewed with the parent / guardian / decision-maker of the subject at each visit.

[0145] Justification of the design of this study For this Phase I / II trial, data will be analyzed according to serological status. Baseline serological status will be retrospectively determined from serum samples collected at baseline. Participants will be classified as having a history of RSV infection or not based on the presence or absence of detectable serum RSV anti-F IgA antibodies. This biomarker was chosen because it is produced only in response to RSV infection and is not transplacentally transmitted from mother to child.

[0146] Evaluation of post-vaccination immunogenicity at day 56 for cohorts 1, 2, 3, and 4, and at day 84 for cohorts 2 and 4: To date, all studies with attenuated live RSV candidate vaccines have used day 56 as the point to assess the serum antibody response after single-dose vaccination. This point is used for two reasons: 1) because this is a primary response (rather than a memory response), the serum antibody response may not have reached its maximum level by day 28, and 2) maximum replication of these highly attenuated vaccine viruses typically does not occur until day 7, which can also delay the induction of an immune response. In subjects receiving two doses of vaccine, it is no longer likely to be a primary response, but rather a memory response, and the serum antibody response is most likely to reach its maximum by day 28 after the second dose.

[0147] RSV surveillance during the RSV epidemic or post-vaccination period for Cohort 4: Based on historical data on RSV seasonality in the United States, Canada, Chile, Honduras, and South Africa, RSV-related illness surveillance was primarily conducted during the NH (November 1 to March 31) and SH (May 1 to September 30) RSV epidemic seasons, respectively, adjusted to local facility-specific RSV seasonality. Due to the global disruption of RSV epidemic patterns, it is unclear when normal seasonal infections will resume, although some suggest a rebound in the NH during the winter of 2021-2022. Because the RSV epidemic season is unpredictable due to the impact of non-pharmacological interventions for COVID-19, study enrollment and vaccination were continued regardless of RSV activity. Study participants enrolled before the normal winter RSV epidemic season in each region were followed up until the month following the end of the normal epidemic season (i.e., April for NH and October for SH). Study participants enrolled during typical RSV outbreaks (i.e., November to March for NH and May to September for SH) were followed up for at least five months after the final dose of vaccine. During the RSV outbreak or post-vaccination RSV surveillance, participants were monitored for respiratory illnesses leading to symptomatic medical visits. It should be noted that this surveillance may overlap with the acute and post-acute phases. In such cases, the necessary assessments were performed for each relevant study phase.

[0148] 5.6log 10 and 6.2log 10 Evaluation of two vaccine doses for PFU: In a previous Phase Ia study conducted by the NIH, 10 6 PFU dose of RSV ΔNS2 / Δ1313 / I1314L (NIH) vaccine is 10 5 It showed better infectivity and serum neutralizing antibody response rates than PFU doses, and higher doses (10 6No evidence of excessive airway disease associated with receiving PFUs was demonstrated. However, in these studies, the vaccine was administered intranasally as a nasal spray in a volume of 0.5 mL (approximately 0.25 mL per nostril) using a sterile needleless 1 mL oral syringe. In this study, the vaccine was administered as a fine nasal mist in a total volume of 0.2 mL (approximately 0.1 mL per nostril) using an intranasal atomizer, the MAD Nasal 130 device, so the 10% when administered by an intranasal atomizer 5 PFU and 10 6 The safety of both doses of PFU needs to be re-evaluated. For both doses, the use of an intranasal atomizer may improve overall vaccine delivery and increase replication. Furthermore, atomizer use is beneficial for low doses (10 5 The infectivity of PFU may also improve. 10 5 PFU and 10 6 The PFU dose was the minimum dose to be exposed using the MAD Nasal 130 device. The target was at least 5.6 log. 10 PFU and 6.2log 10 The levels were as high as PFU, and therefore these doses were most likely due to manufacturing requirements / variations.

[0149] Evaluation of the two-dose vaccine regimen: Several previously published studies have evaluated two or three doses of attenuated RSV or parainfluenza virus type 3 (PIV3) candidate vaccines. Generally, there were high levels of limitations with the second dose, and the serological immune response was limited. The main effect was vaccine infectivity in individuals that did not respond to the first dose. Two doses of RSVΔNS2 / Δ1313 / I1314L(Sanofi) may improve infectivity at either dose.

[0150] Selection of vaccine dose based on safety, infectivity, viral shedding, and immunogenicity in infants and toddlers, regardless of baseline RSV serological status:

[0151] This includes an open-label interim analysis for dose selection of the RSVΔNS2 / Δ1313 / I1314L(Sanofi) vaccine for subjects from Cohorts 1, 2, and 3 and at least 90 subjects enrolled in Cohort 4. This interim analysis was performed when subjects provided safety data up to D84 and D84 immunogenicity results became available. RSV serologically negative infants and toddlers are most likely to be RSV-uninfected and exhibit sufficient vaccine viral infectivity, shedding, and immunogenicity (from serum neutralizing antibody titers); however, vaccine doses were selected based on a benefit:risk assessment using data on the inventors' target population for this vaccine (i.e., all infants and toddlers regardless of serological status). The selected doses will be used in future research.

[0152] Placebo group: To establish background respiratory and febrile illness rates in infants and toddlers, each cohort included a placebo recipient.

[0153] Clinical Hypothesis: Both doses of the attenuated live RSV ΔNS2 / Δ1313 / I1314L (Sanofi) vaccine are assumed to be safe and immunogenic in infants and toddlers. However, both doses may be associated with adverse events that become apparent only when analyzed in a larger population than the number of participants enrolled in the Laboratory of Infectious Disease (LID) / National Institute of Allergy and Infectious Disease (NIAID) / NIH Phase Ia studies, where 10–40 vaccinated individuals were identified per study. In addition, the rate, extent, and persistence of antibody responses, as well as the degree of memory (past) antibody responses observed after naturally occurring RSV infections, may differ depending on the dose. The intranasal atomizer device used in this study may also affect the safety and immunogenicity of the vaccine. Future dose selection will be based on a descriptive comparison of the safety, infectivity, and immunogenicity of one or two doses of either dose category.

[0154] Safety plan:

[0155] [Table 16]

[0156] [Table 17]

[0157] Visit Procedure In-person consultation For cohorts 1, 2, 3, and 4, visit 01 (day 0) Table 4 shows the timelines for registration completion (visit 01), vaccination, and RSV surveillance for each hemisphere.

[0158] [Table 18]

[0159] Visit 01 (Day 0): Enrollment, randomization, and vaccination procedures for cohorts 1, 2, 3, and 4 (all subjects). 1) Provide the parent / guardian / legal representative of the subject with information about this study, obtain their written informed consent, and give them a signed copy. 2) Collect demographic data (date of birth, sex, race, and ethnicity). 3) Confirm the inclusion and exclusion criteria regarding eligibility. 4) Take an oral medical history of the subject, including any past and current medications, any signs and symptoms, and any developmental delays. 5) Review any past medical records, including immunology records, to ensure that the subject does not meet exclusion criteria 2, 3, and 21. 6) Before randomization, a full physical examination will be performed, including body temperature, heart rate, respiratory rate, weight, height, and assessment of HEENT [head, eyes, ears, nose, and throat], lungs, heart, and abdomen, as well as musculoskeletal examination, age-appropriate neurological examination, and skin examination. 7) Conduct point-of-care diagnostic testing (POC) for COVID-19. 8) Inquire with the IRT regarding the target number, randomization, and dose number based on age subgroups. 9) Take an initial blood sample and examine the baseline RSV serum antibody status, i.e., the serum RSV-nAb titer. 10) Administer the appropriate investigational drug in accordance with the instructions provided for intranasal administration of the research vaccine using the MAD Nasal 130 device. 11) Observe the subject for 30 minutes, and if any adverse reactions occur, record them in the original document. 12) Distribute or download the Daily Card (DC1) / eDC and thermometer to the parent / guardian / legal representative, and encourage them to read the instructions for use and to remember to fill in the pages for days 0-7 of the DC1 / eDC. The parent / guardian / legal representative will record the child's temperature and signs of illness (requested involuntary reporting responses and spontaneous reporting AEs, including AESI, MAAE, and SAE) in the DC1 / eDC. 13) Parents / guardians / decision-makers should wait for daily phone calls from the research facility nurse after this immunotherapy visit 01 to confirm what has been filled out on DC1 / eDC each day; and should be reminded to complete the remaining entries on DC1 / eDC and bring it with them on the designated visit 02 date. 14) Encourage the parent / guardian / decision-maker to notify the facility if SAE or any other illness occurs. After assessment, facility staff will, if necessary, schedule the facility's notification and subsequent visit within the prescribed time frame. 15) Complete a relevant case report form (CRF) for this visit.

[0160] Visit 02: Visit procedure 7 days after vaccination 1 for cohorts 1, 2, 3, and 4 (all subjects) 1) Review the patient's medical history, including past and current medications, since their last visit. 2) Perform focused clinical tests including body temperature, pulse rate, respiratory rate, eye, ear, nose, and throat (EENT), respiratory system, cardiac system, and lymphatic system. 3) Collect a nasal swab sample for viral quantification of vaccine virus shedding. If the subject meets the criteria for presenting to the hospital on day 7 due to the onset of illness, the same nasal swab specimen may also be used to test for respiratory pathogens. 4) Review the responses from involuntary reports based on requests, as well as voluntary reports of AE, AESI, MAAE, and SAE, with the parent / guardian / decision-maker in question using the completed DC1 / eDC. Instruct them to complete DC2. 5) If a SAE occurs, follow the reporting instructions. Encourage staff to remember to notify the facility if an SAE occurs. 6) Complete any relevant CRFs regarding this visit. 7) Encourage the parent / guardian / representative to remember the next appointment.

[0161] Visit 03: Visit procedure 56 days + 7 days after vaccination for cohorts 1 and 3 1) Review the patient's medical history, including past and current medications, since their last visit. Check for any contraindications. 2) Perform focused clinical tests including body temperature, pulse rate, respiratory rate, EENT, respiratory system, cardiac system, and lymphatic system. 3) Collect a blood sample for serum antibodies against RSV. 4) Collect the SAEs on the completed DC1 and DC2 / eDC and verify them with the parent / guardian / decision-maker in question. Distribute the MAs. 5) If a SAE occurs, follow the instructions given there regarding reporting it. Encourage staff to remember to notify the facility if an SAE occurs. 6) Complete any relevant CRFs regarding this visit. 7) Encourage the parent / guardian / representative to remember the next appointment.

[0162] Visit 03: Visit procedure 56 days + 7 days after vaccination for cohorts 2 and 4 1) Take an oral medical history of the subject, including any medications and immunotherapy they have taken in the past or are currently taking. 2) Check for contraindications before receiving the second dose of the vaccine. 3) Before vaccination, a focused clinical examination will be conducted, including body temperature, pulse rate, respiratory rate, EENT, respiratory system, cardiac system, and lymphatic system. 4) Conduct COVID-19 POC diagnostic tests. 5) Collect information on concomitant medications / vaccinations that should be reported. 6) Inquire with the IRT regarding the dosage. 7) Collect a blood sample for serum antibodies against RSV. 8) Administer the appropriate investigational drug in accordance with the instructions provided for intranasal administration of the research vaccine using the MAD Nasal 130 device. 9) Observe the subject for 30 minutes, and if any adverse reactions occur, record them in the original document. 10) Collect responses from involuntary reports based on requests, as well as voluntary reports including AESI, MAAE, and SAE, using completed DC1 and DC2 / eDC forms, and review them with the subject's parent / guardian / decision-maker. 11) Distribute or download the Daily Card (DC3) / eDC and thermometer to the parent / guardian / legal representative, have them review the instructions for use, and ensure they complete pages 0-7 of the DC3 / eDC. The parent / guardian / legal representative will record the child's temperature and signs of illness (including involuntary responses based on requests, and spontaneous AEs, including AESI, MAAE, and SAE) in the DC3 / eDC. 12) After this visit 04, the parent / guardian / decision-maker should wait for a daily phone call from the research facility nurse to confirm what was filled out on DC3 / eDC each day, and should be reminded to complete the DC3 entries and bring it with them on the date and time specified at visit 05. 13) Encourage the parent / guardian / decision-maker to notify the facility if SAE or any other illness occurs. After assessment, facility staff will, if necessary, schedule the facility's notification and subsequent visit within the prescribed time frame. 14) Complete any relevant CRFs regarding this visit.

[0163] For all cohorts, visits were made during the post-RSV epidemic period or at least 5 months after the final dose of the vaccine (visit 04 for cohorts 1 and 3, or visit 06 for cohorts 2 and 4). 1) Collect a blood sample for serum antibodies against RSV. 2) Confirm the MA regarding SAE with the parent / guardian / decision-maker concerned. 3) If a SAE occurs, follow the instructions given there regarding reporting it. Encourage staff to remember to notify the facility if an SAE occurs. 4) Record the relevant CRFs and study completion CRFs for this visit.

[0164] Visit 04: Visit procedure for cohorts 2 and 4 on D63+7 (7 days after vaccination 2) following vaccination 1. 1) Review the patient's medical history, including past and current medications, since their last visit. 2) Perform focused clinical tests including body temperature, pulse rate, respiratory rate, EENT, respiratory system, cardiac system, and lymphatic system. 3) Collect nasal swab samples for quantifying vaccine virus shedding. If the subject meets the criteria for presenting to the hospital with the onset of illness, the same nasal swab specimen may also be used to test for respiratory pathogens. 4) Review the responses from involuntary reports based on requests, as well as voluntary reports of AE, AESI, MAAE, and SAE, together with the parent / guardian / decision-maker in question using the completed DC3 / eDC. 5) If a SAE occurs, follow the instructions provided there regarding reporting it. Encourage staff to remember to notify the facility if an SAE occurs. 6) Complete any relevant CRFs regarding this visit.

[0165] Visit 05: Visit procedure for cohorts 2 and 4 on D84+8 (28 days + 8 days after vaccination 2) following vaccination 1. 1) Review the patient's medical history, including past and current medications and immunotherapy treatments, since their last visit. 2) Perform focused clinical tests including body temperature, pulse rate, respiratory rate, EENT, respiratory system, cardiac system, and lymphatic system. 3) Collect a blood sample for serum antibodies against RSV. 4) With the Collect and completed DC3 / eDC, confirm the responses from involuntary reports based on requests, as well as voluntary reports of AE, AESI, MAAE, and SAE, together with the parent / guardian / decision-maker in question. Distribute MA. 5) If a SAE occurs, follow the instructions given there regarding reporting it. Encourage staff to remember to notify the facility if an SAE occurs. 6) Complete any relevant CRFs regarding this visit.

[0166] Patient visit 99: Patient came to the hospital upon onset of illness. Patient visits due to illness can be conducted remotely, as a home visit, or as an in-person visit, at the discretion of the principal investigator. The requirements for a patient visit and the type of visit were initially assessed via video call. Video calls were used to initially assess the clinical condition of the study subjects and, in particular, whether mild (grade 1) illnesses could be managed remotely. This phased management of patient visits due to illness is necessary in the current global COVID-19 pandemic to limit the number of contacts between study subjects and research facility staff to only those that are absolutely necessary.

[0167] The time frame for a post-notification visit to the facility for the onset of illness, if deemed necessary by the principal investigator, depends on the grading of fever and respiratory symptoms and the phase of the study. If the onset visit occurs on the same day as a routine study visit for which a nasal swab specimen is to be collected, the same nasal swab specimen may be used for respiratory pathogen testing. A second nasal swab must be collected 48 hours later. If the onset visit occurs on the same day as a routine study visit for which a nasal swab specimen is not to be collected, a nasal swab specimen is required for respiratory pathogen testing. A second nasal swab must be collected 48 hours later.

[0168] If a disease / safety event occurs, the study subject must be managed in accordance with the standard of care at the facility / local area, including the performance of clinical tests necessary for the diagnosis and / or management of the study subject. After the onset of the disease and the patient's arrival at the hospital, healthcare professionals must continue to follow the subject until the condition is resolved.

[0169] Patients may visit the hospital at any time during this study. The time frame for patient visits due to illness is summarized in Table 5.

[0170] [Table 19]

[0171] The procedure for coming to the hospital after the onset of illness is as follows: 1) Take an oral medical history of the subject, including any medications and immunotherapy they have taken in the past or are currently taking. 2) Determine whether the patient can be managed remotely, or whether a home visit or in-person visit is necessary. 3) When making a home visit or coming to the clinic, focus clinical tests will be performed, including body temperature, pulse rate, respiratory rate, EENT, respiratory system, cardiac system, and lymphatic system. 4) Collect AEs, AESIs, MAAEs, and SAEs from requested and voluntary reports using completed DC / eDCs or memory aids, and verify them with the parent / guardian / decision-maker of the subject. 5) If a SAE occurs, follow the instructions given there regarding reporting it. In the case of an SAE, be sure to notify the facility if the illness began within 28 days of vaccination. 6) Collect nasal swab samples for RSV virus detection and quantification, and for real-time reverse transcriptase polymerase chain reaction (rRT-PCR) for respiratory pathogens. 7) COVID-19 testing will be performed as needed, in accordance with the opinion of the principal investigator and the CDC COVID testing algorithm (see cdc.gov / coronavirus / 2019-ncov / lab / resources / Antigen_Testing_Algorithm_2020-12-14_v03_NO_DRAFT_SPW_508.pdf for details on the CDC COVID testing algorithm). 8) Complete any relevant CRFs regarding this visit. 9) Schedule follow-up appointments as needed, including visits for 48-hour follow-up to collect nasal swabs. 10) If a disease / safety event occurs, the subject must be managed in accordance with the standard of care at the facility / local area, including the performance of clinical tests necessary for the diagnosis and / or management of the study subject.

[0172] Follow-up for individuals who experienced adverse reactions (AEs) resulting from involuntary reporting based on requests or discontinuation of research / vaccination:

[0173] Unless the subject or their parent / guardian / decision-maker refuses further contact, each subject who experiences an AE (whether serious or not) during the study must be followed up until the condition resolves, stabilizes, or becomes chronic (even after the subject's participation in the study has ended) if any of the following apply: 1. According to the principal investigator, the adverse event (AE) is thought to be related to the administered product. 2. The study or vaccination program was discontinued as a result of the adverse event (AE).

[0174] Non-in-person telephone consultation Acute care telephone consultation to confirm DC up to D29+1 (Cohorts 1, 2, 3, and 4) and D84+8 (Cohorts 2 and 4) Note: If any of the acute non-in-hospital visits fall on a weekend or holiday, the telephone consultation may be conducted on the next business day. All telephone consultations by the parent / guardian / decision-maker must be conducted by a qualified person, such as a physician or a qualified research nurse. 1) Based on the information entered in the DC, check for responses from involuntary reports based on requests, and for AEs, AESIs, MAAEs, and SAEs from spontaneous reports. After evaluation, if necessary, facility staff will schedule the patient's visit to the hospital within an appropriate time window from the facility's notification. 2) If necessary, record relevant information about the subject's health status, including any changes in medication and immunotherapy, on the telephone consultation form and CRF. After evaluation, if necessary, facility staff will schedule the patient's visit within the prescribed time frame from the facility's notification to the onset of illness. 3) If a SAE occurs, follow the instructions given there regarding reporting it. Also, be sure to notify the facility if an SAE occurs. 4) Encourage the parent / guardian / representative to remember to do the following: • Fill in the remaining pages of your daily card / electronic daily card and bring it with you to your next appointment. • If a SAE occurs, notify the facility.

[0175] Telephone consultation on day 42 + 1 day (Cohorts 1, 2, 3, and 4) 1) If necessary, record relevant information about the subject's health status, including any changes in medication and immunotherapy, on the telephone consultation form and CRF. After evaluation, if necessary, facility staff will schedule the patient's visit within the prescribed time frame from the facility's notification to the onset of illness. 2) If a SAE occurs, follow the instructions given there regarding reporting it. Also, be sure to notify the facility if an SAE occurs. 3) Encourage the parent / guardian / representative to remember to do the following: • Fill in the remaining pages of your daily card / electronic daily card and bring it with you to your next appointment. • If a SAE occurs, notify the facility.

[0176] Telephone consultations during the RSV epidemic or post-vaccination RSV surveillance period. During the RSV season (November 1 to March 31 in the Northern Hemisphere, and May 1 to September 30 in the Southern Hemisphere) or during post-vaccination RSV surveillance (at least 5 months after the final dose of vaccine), telephone consultations should be conducted every two weeks with a parent / guardian / legal representative. 1) Record relevant information about the subject's health status, including any changes in medication or immunotherapy, in the telephone consultation form. 2) For illnesses that lead to a visit to a medical institution of the following types, namely fever, URI, LRI, or otitis media, schedule a telephone consultation followed by a visit to the hospital within the guidelines and prescribed time frame. If the illness overlaps with the acute or post-acute phase, the time frame specified for the relevant acute or post-acute phase must be used. 3) If a subject experiences a serious adverse event (SAE) and receives medical attention from a physician other than the clinical trial participant or from another hospital (at any point during the study), a schedule will be made for the subject to visit the facility upon discharge to collect nasal swab samples for RSV virus detection and quantification, as well as for rRT-PCR for respiratory pathogens. 4) If a SAE occurs, follow the instructions given there regarding reporting it. Encourage staff to remember to notify the facility if an SAE occurs.

[0177] Early Safety Data Review The safety of the investigational drug was continuously monitored by the sponsor. To enable a cautious, stepwise approach to vaccine administration, an Early Safety Data Review (ESDR) was conducted between scheduled SMT meetings. Cohort 1 - ESDR / SMT at Day 7 after vaccination - ESDR / SMT at D28 after vaccination - ESDR / SMT in D56 after vaccination Cohort 2 - ESDR / SMT at Day 7 after vaccination - ESDR / SMT at D28 after vaccination - ESDR / SMT in D84 after vaccination Cohort 3 - ESDR / SMT at Day 7 after vaccination - ESDR / SMT at D28 after vaccination - ESDR / SMT in D56 after vaccination • Cohort 4 - ESDR / SMT at Day 7 after vaccination - ESDR / SMT at D28 after vaccination - ESDR / SMT in D84 after vaccination

[0178] The collected safety data was entered into the CRB and compiled by the sponsor in a blinded manner for each ESDR. The ESDRs were conducted by the sponsor during SMT meetings. Enrollment was not suspended during the SMT review.

[0179] It is understood that all reviews are based on preliminary data that has not undergone validation and database locking. Current routine safety signal monitoring processes, other than those designated as early interim safety analyses in the protocol, will continue without modification.

[0180] If, at any other point in this study, a predetermined alarm threshold for a safety event is reached, this trial will be temporarily suspended to open an emergency SMT, regardless of the current study period.

[0181] During the safety evaluation, a Bayesian method based on the posterior distribution was used to determine the difference between each RSV formulation and placebo for the following safety endpoints: • Any grade 3 lower respiratory tract disease, such as wheezing, pneumonia, persistent tachypnea, or laryngotracheobronchitis. • Grade 3 overheating

[0182] The probability that the difference in the rate of events occurring between a single RSV formulation and placebo is greater than a predetermined margin (δ) can be calculated based on the posterior distribution using the non-informative prior distribution β(1,1) and binomial data observations:

number

[0183] If this probability is high (e.g., ≥80%), it may be recommended to withdraw the formulation. Therefore, this can be helpful in safety assessment decision-making by SMT and / or IDMC (if applicable), and can also be applied at the end of this study.

[0184] If the SMT's review of the data fails to identify potential safety signals, SMT monitoring will be initiated as specified in the SMT Declaration. When safety signals are identified, the SMT will investigate the events, complete a safety analysis and / or assessment report, and determine the safety signals and any further actions and / or recommendations, including: • Extend or temporarily suspend the trial and submit it to the Vaccine Adjudication Committee (VAC) for further consideration. • Conduct research and prepare a report. • We recommend continuing the exam.

[0185] During the investigation, the team may consult with non-clinical safety experts and research team members regarding whether there may be a mechanism underlying the event and, if necessary, a review of toxicity data or other internal expert opinions.

[0186] If there are disagreements within the team, the core team will seek advice from the VAC on their respective job management immediately after the SMT meeting. In particular, in cases where the signal escalation of the PSB review is problematic, the head of the Vaccine Pharmacovigilance Global Business Unit (PV GBU) or the head of Vaccines GBU Clinical & Sciences may also be sought for advice.

[0187] After the SMT core team agrees that there are safety signals that could potentially affect the safety of the subject, the conduct of the study (temporary suspension, extension of suspension, or termination), or the design (requiring changes), the SMT PM will inform the head of the Vaccine PV GBU who will verify the validity of the signals, and will immediately contact the head of the Vaccine GBU's Clinical and Scientific Division and the chair of the PSB to make a decision on whether or not to hold the PSB.

[0188] Based on the findings and recommendations from the PSB, the SMT may implement one of the following functional responses related to the conduct and supervision of the research, including: Continue with this exam. • Extend the suspension to conduct further evaluations, for example, an ad-hoc IDMC. • Change the test design, or The exam will be canceled.

[0189] An ad-hoc IDMC, ideally comprising at least two pediatric respiratory virus vaccine specialists, will review open-label study data at the request of the SMT. The ad-hoc IDMC will review relevant safety information and available data, including the extent of vaccine virus shedding, at the request of the SMT. If an ad-hoc IDMC meeting is necessary, the ad-hoc IDMC will review the safety data available at that time and determine whether the adverse events can be attributed to etiologies, causes, or diagnoses unrelated to the study vaccine, and whether one or more adverse events are related to vaccine virus shedding at the time the events occurred (even if others are identified). If the ad-hoc IDMC determines that there is no established causal relationship between the adverse events and the study vaccine, the study may continue without modification. Based on the IDMC's assessment, the sponsor SMT will determine whether there is a causal relationship between the adverse events and the study vaccine, and the SMT will then... Should the internal signal detection process (SOP#RDWIN-000390) be performed? Should validated signals for PSB be gradually increased as needed? Should we continue with this exam? Should the test design (including input of PSB and temporary IDMC) be changed, or Should the test (involving PSB and temporary IDMC input) be canceled? This will determine the outcome.

[0190] As part of the early safety review, the following safety parameters will be determined: • Immediate response • Respiratory and systemic reactions reported involuntary based on requests. • Spontaneous reports, i.e., AEs reported as related by the principal investigator. SAE, MAAE, and AESI

[0191] Registration was not temporarily suspended during the review process. The following data was examined: 1) Regardless of causal relationship, was there a death? 2) Were there any vaccine-related SAEs? 3) Were there any cases of Grade 3 fever reported in more than two subjects? 4) Were there any adverse events other than fever that were involuntarily reported based on requests for Grade 3 or higher? 5) During the acute phase (i.e., within 28 days after vaccination), was lower respiratory tract disease of grade 2 or higher on the DAIDS rating scale observed in more than one subject (excluding wheezing according to the Brighton Collaboration severity rating scale)? 6) Was an AESI of grade 3 or higher on the DAIDS rating scale observed in the subject during the acute phase (i.e., within 28 days after vaccination), including lower respiratory tract diseases? (However, wheezing on the Brighton Collaboration severity rating scale is excluded.) 7) Were there more than one case of spontaneously reported Grade 3 adverse event (AE) during the acute phase (i.e., within 28 days after vaccination)? 8) Any other pattern of study-related clinical laboratory values ​​or clinical symptoms other than fever that the principal investigator deems sufficiently unsafe.

[0192] If any of the above criteria are met, a decision will be made regarding whether enrollment in this study can be reopened.

[0193] As determined by SMT, blinding of cases may be deblinded as needed.

[0194] Registration and maintenance of research groups Application Procedure Prior to the commencement of this study, the principal investigator and / or researcher determined the recruitment strategy to be used at their site for this study (e.g., advertising, databases, direct mail, or word-of-mouth referrals). The physicians contacted a pool of potential and appropriate parents / guardians / decision-makers using relevant methods and invited them to participate in this study. The site ensured that all materials used for participant recruitment (e.g., information booklets, letters, brochures, posters, other advertisements, etc.) were submitted to the sponsor before being submitted to the IRB for approval.

[0195] In addition, parents / guardians / decision-makers who brought their children to the research facility for regular medical appointments were asked to enroll their children in this study if they were eligible. Participants were also recruited from the general population.

[0196] Informed Consent Procedure Informed consent is the process by which a person's guardian or appropriate legal representative confirms their willingness to participate in a particular research study. Informed consent must be obtained before any research procedure is carried out. This process is documented using an ICF (International Classification of Functioning, Disability and Health) with a written signature and date.

[0197] According to GCP, before signing and datening the consent form, the guardian / representative of the subject must inform the appropriate research personnel about all aspects of the research relevant to their decision to participate, and must have sufficient time and opportunity to ask questions.

[0198] If the subject's guardian / legal decision-maker is unable to read or sign the ICF, the consent form must be signed and dated by an impartial witness independent of the principal investigator. The witness signing and dated the consent form ensures that the information contained in the consent form and any other written information has been accurately explained to and understood by the subject or their guardian / legal decision-maker.

[0199] The actual ICF used at each site may vary depending on local regulations and IEC / IRB requirements. However, all versions must include the standard information found in the sample ICF provided by the sponsor. Any changes to the ICF must be approved by the sponsor and the IEC / IRB before the format is used.

[0200] When new information became available that could relate to the guardian / decision-maker's intention to continue participating in the study, it was communicated to the person in question in a timely manner. Such information was provided through the revised ICF or the supplements to the original ICF.

[0201] The informed consent form was provided in two copies, an original and a duplicate, or a photographic copy of the signed consent form was made. The original was kept by the principal investigator, and the copy was kept by the subject's guardian / legal decision-maker.

[0202] The consent process was documented in the original source material.

[0203] The rationale for including subjects who are not capable of giving consent: The rationale for conducting this study in a pediatric population is included above.

[0204] Screening Criteria Aside from inclusion and exclusion criteria, there are no screening criteria. The principal investigator must confirm the inclusion and exclusion criteria at the time of enrollment (visit 01).

[0205] Inclusion criteria: To be eligible for study registration at visit 01, participants must meet all of the following criteria: 1. D0 is for babies aged 6-18 months. (6-18 months means from the 6th month after birth until the day before the 19th month after birth). 2. The informed consent form was signed and dated by one or more parents / guardians / or other representatives (and, where required by local regulations, an independent witness). 3. The subject and their parent / guardian / legal representative must be able to accompany them to all scheduled hospital visits and follow all examination procedures.

[0206] Exclusion criteria: Individuals who meet any of the following criteria must be excluded from exam registration: 1. At the time of study enrollment (or within 6 weeks prior to the first trial vaccination), you are participating in, or are scheduled to participate in, another clinical trial investigating a vaccine, drug, medical device, or medical procedure. 2. You have received one of the following vaccines before registering: • Any influenza vaccine administered within the previous 7 days, or • Any inactivated vaccine administered within the previous 14 days, or • A live attenuated rotavirus vaccine administered within the past 14 days, or • Any live vaccine other than rotavirus vaccine administered within the previous 28 days, • Another clinical trial vaccine or clinical trial drug within the previous 28 days. 3. You have previously received an approved or clinical trial RSV vaccine, or have previously received or are scheduled to receive any anti-RSV product (such as ribavirin, RSV immunoglobulin [IG], or RSV monoclonal antibody). 4. You received immunoglobulin, blood, or blood-derived products in the six months prior to registration. 5. Known or suspected congenital or acquired immunodeficiency; or immunosuppressive therapy such as anticancer chemotherapy or radiotherapy within the past six months; or long-term systemic corticosteroid therapy (prednisone or equivalent for more than two consecutive weeks within the past three months). 6. Cases of suspected or confirmed COVID-19. 7. A known systemic hypersensitivity to any of the vaccine components, or a history of a life-threatening reaction to the vaccine used in this study or a vaccine containing any of the same substance. 8. Any kind of chronic illness. Chronic diseases, though not limited to them, may include heart disorders, lung diseases (including any history of reactive airway disease, treatment with bronchodilators, or medically diagnosed wheezing), renal disorders, autoimmune disorders, diabetes, psychomotor disorders, and known congenital or hereditary disorders. 9. Any medical history of wheezing. 10. Any acute febrile, respiratory, or gastrointestinal illness within the past 24 hours that is sufficiently severe to interfere with successful vaccination on the day of vaccination, as determined by the principal investigator. Those expected to be included in this study should not be enrolled until their condition has resolved or the fever has subsided. 11. You received any of the following medications within 3 days prior to registering for the study: • Systemic antibacterial agents, antiviral agents, antifungal agents, antiparasitic agents, or antituberculosis agents, whether for therapeutic or preventive purposes, • Intranasal drugs, or Other prescription drugs, excluding permitted concomitant medications (prescription or non-prescription), including nutritional supplements, gastroesophageal reflux disease medications, eye drops, and topical medications, including (but not limited to) skin (topical) steroids, topical antibiotics, and topical antifungals. 12. The patient received salicylate (aspirin) or a salicylate-containing preparation within 28 days prior to registration. 13. The patient is under emergency treatment or is hospitalized involuntarily and deprived of their freedom. 14. Identified as the biological or adopted child of the principal investigator or an employee directly involved in the proposed research. 15. Any past anaphylactic reaction. 16. Any past vaccine-related adverse reaction of grade 3 or higher. Note: If grade classification is not possible, determine whether the reaction was considered severe or life-threatening; if so, it will be excluded. 17. On the registration date (or within the six weeks prior to the first clinical trial vaccination), the applicant is a member of a household that has or will have an infant under six months of age for up to 28 days. 18. A member of a household that has enrolled in or plans to enroll in this study in the same year, and whose enrollment date does not coincide with that of the one or more participants residing in that household (i.e., all eligible children belonging to the same household must be enrolled on the same day). 19. It is not limited, • People infected with HIV • People who have received chemotherapy within 12 months prior to registration • People receiving immunosuppressants • People who have survived solid organ transplants or bone marrow transplants This includes members of households with immunocompromised individuals. 20. The child attends a daycare facility and shares a daycare room with an infant under 6 months of age, and the parent / guardian / decision-maker has neither the ability nor the willingness to temporarily suspend the child's attendance at daycare for 28 days after vaccination. 21. The following scheduled doses after planned vaccination: • Any influenza vaccine administered within 7 days of vaccination, • Inactivated vaccine or attenuated live rotavirus vaccine administered within 14 days of vaccination, • Any live vaccine other than rotavirus within 28 days after vaccination, • Another clinical trial vaccine or clinical trial drug within 56 days of vaccination. 22. Born before 34 weeks of gestation. 23. Born before 37 weeks of gestation and under 1 year old at the time of registration. 24. There is currently a suspected or documented developmental disorder, delay, or other developmental problem. 25. The child has previously received any form of oxygen therapy at home or in a hospital, except for temporary oxygen supplementation for transient tachypnea of ​​the newborn.

[0207] Medical history Prior to enrollment, eligibility was determined based on both past and ongoing pre-existing conditions and diseases. All such conditions were documented in the source materials. Important (clinically relevant) medical history (reported as a diagnosis) was collected in the CRB, including conditions / diseases that the subject was or had been under physician's supervision of, or that were likely to recur during the course of the study or lead to SAEs or frequent outpatient visits. The important medical history section of the CRB includes a central list of organ systems and disorders that can be used to facilitate comprehensive reporting, as well as sections for reporting specific conditions and diseases.

[0208] For each pathological condition, the collected data was limited to the following: • Diagnosis (this is preferable to reporting signs and symptoms) • Presence or absence of the medical condition at the time of registration • It is strongly discouraged to report signs and symptoms instead of making a diagnosis.

[0209] The collected information was not coded, and the date, drug, and organ system were not recorded. The purpose of limiting the data was to assist in the interpretation of safety data collected in subsequent studies.

[0210] Contraindications for subsequent vaccinations temporary contraindications If any of the following conditions are observed in a subject on day 0 (Cohorts 1, 2, 3, and 4) or day 56 (Cohorts 2 and 4), the principal investigator shall postpone further vaccination until the condition is resolved. The postponement must still be within the vaccination timeframe, i.e., within 5 days of randomization on day 0 (Cohorts 1, 2, 3, and 4) and within 7 days of day 56 (Cohorts 2 and 4).

[0211] In the judgment of the principal investigator, any acute febrile illness (rectal temperature ≥ 38.0°C [≥ 100.4°F]), acute otitis media, upper and lower respiratory signs or symptoms (including, but not limited to, rhinorrhea, cough, and pharyngitis), or nasal congestion that is sufficiently severe to interfere with the successful absorption of the investigational drug within the past 24 hours.

[0212] Before receiving any research vaccine or before scheduled administration after any research vaccine, receive one of the following: • Any influenza vaccine administered within the previous 7 days, or • Any inactivated vaccine or a live attenuated rotavirus vaccine administered within the past 14 days, • Any live vaccine other than rotavirus vaccine administered within the previous 28 days, • Another clinical trial vaccine or clinical trial drug within the previous 28 days.

[0213] All eligible subjects belonging to the same household who are registered on the same day must receive the clinical trial drug on the same day; therefore, if one child is found to have the disease described above, the administration of the drug must be postponed for both children.

[0214] Definitive contraindications If any of the following conditions were observed in a participant, the principal investigator discontinued vaccination: • Anaphylaxis or any other serious allergic reaction to the previous dose of the vaccine. • Any adverse event (AE) greater than Grade 2, any grade of latent adverse event (LRI), or a sustained adverse event (SAE) determined by the principal investigator to be related to the previous dose of the vaccine. • Diagnosis of COVID-19

[0215] For subjects with critical contraindications, follow-up regarding safety and immunogenicity assessments was continued, where applicable, according to the study's regulations.

[0216] For example, in cases where there was a local or national immunization program using a pandemic vaccine, such as for influenza, participants who received the pandemic vaccine at any point during this study were excluded from the study.

[0217] Withdrawal conditions Parents / guardians / decision-makers were informed that they had the right to withdraw their children from the study at any time. All participants who received the clinical trial drug were encouraged to remain in study follow-up for the duration of the study, even if they refused to have their samples collected.

[0218] The subjects are selected from the research, • Members may withdraw from the program upon request, either verbally or in writing, from their parent / guardian / representative (i.e., withdrawal / absence of consent). • At the discretion of the Principal Investigator or the sponsor, a participant may withdraw from the trial without the permission of a parent / guardian / legal representative (i.e., due to non-compliance with the protocol / withdrawal) due to safety concerns arising from significant protocol non-compliance (based on the Principal Investigator's judgment).

[0219] The reasons for withdrawal or omission must be clearly documented in the source documents and the CRB.

[0220] The principal investigator must determine whether the voluntary withdrawal is due to safety concerns (and if so, the reason for discontinuation must be noted as an "adverse event") or for another reason.

[0221] We decided to replace those who withdrew.

[0222] For any participant who withdrew from or terminated the study before the completion of scheduled follow-up, the researcher documented the reasons for withdrawal or termination in detail and made every effort to complete the following final assessment: 1) Take an oral medical history of the subject, including any medications and immunotherapy they have taken in the past or are currently taking. 2) If possible, collect a blood sample for serum antibodies against RSV. 3) Nasal swab samples may be collected, at the discretion of the principal investigator, for the purpose of quantifying vaccine virus shedding (in the acute phase) and for point-of-care testing of other respiratory pathogens, including COVID-19. 4) Complete the relevant sections of the CRF.

[0223] Procedure for cases that cannot be traced If a subject failed to attend a follow-up examination, while fully respecting their rights, documented efforts were made to locate them, recall them, or at least determine their health status (i.e., documented telephone calls and registered mail). These efforts were documented in the original sources.

[0224] Classification of subjects whose research was discontinued For all subjects whose studies were discontinued before completion, the most significant reason for early termination was the examination of CRBs. The reasons are listed below in order from largest to smallest:

[0225] [Table 20]

[0226] Cancellation follow-up The facility completed all scheduled safety follow-ups and contacted all participants whose studies were terminated early due to adverse events (AEs) or protocol deviations.

[0227] In cases where the reason for early termination was that the case could not be tracked, or where the subject withdrew their informed consent and explicitly stated that they did not want to be contacted again, this was documented in the source documents, and the facility did not attempt to obtain any further safety information.

[0228] If the subject's status at the end of this study was "withdrawal by the subject or parent / guardian / legal representative," the facility attempted to contact the subject regarding follow-up visits during the RSV epidemic; however, this was not done if the subject explicitly stated that they did not want to be contacted again, and this was documented in the source material.

[0229] Follow-up of subjects with COVID-19 in this study If a participant developed COVID-19 during this study, they were followed up for as long as possible in accordance with the guidelines of the national / regional / local health authorities. All attempts were made to monitor the safety of the study participants and collect key samples while adhering to the guidelines of the national / regional / local health authorities.

[0230] Safety-related emergency calls If, at the discretion of the principal investigator, an emergency requiring medical intervention is observed in a subject, the principal investigator may contact the sponsor's Research Management Organization (RMO) for advice on how to address any research-related medical questions or issues. If the RMO is unable to respond, the principal investigator may contact the call center—which is available 24 hours a day, 7 days a week—and, as necessary, the call center will forward all safety-related emergency calls to the appropriate primary or backup sponsor contact.

[0231] This process does not replace the requirement to report SAEs. Principal investigators are still required to follow the protocol's procedures for reporting SAEs to the Global Drug Safety Monitoring (GPV) unit.

[0232] In the event of an emergency lockout, the principal investigator must follow the lockout procedure.

[0233] Changes to research and protocols Any modifications to this study plan and protocol must be discussed with and approved by the sponsor. If an agreement is reached regarding the need for modifications, the sponsor will document this in writing and replace the old version with the revised protocol. All substantial modifications (e.g., modifications affecting the conduct of the study or the safety of the subjects) require approval from the IEC / IRB, which must also be forwarded to the regulatory authority.

[0234] Administrative modifications to a protocol that alter some administrative, logistical, or other aspect of the study but do not affect its scientific quality or the safety of the subjects are not required. The IEC / IRB must only be notified and no formal approval is necessary.

[0235] The principal investigator is responsible for ensuring that any changes to an approved study during the period for which IEC / IRB approval has already been granted are not initiated without review and approval by the IEC / IRB, except for changes that eliminate a clear and immediate risk to the subjects.

[0236] Interruption of research This study may be terminated if new data on the investigational drug becomes available from this study or any other study; or for administrative reasons; or at the recommendation of the sponsor, principal investigator, IEC / IRB, or the regulatory authority in the country where the study is being conducted.

[0237] If the study is terminated or temporarily suspended, the sponsor shall promptly notify the principal investigator, the IEC / IRB, the regulatory authorities, and any one or more contract research organizations used in the study of the reasons for the termination or suspension, as stipulated by the applicable regulatory requirements. The principal investigator shall promptly notify the subject's parent / guardian / decision-maker and ensure appropriate therapy and / or follow-up for the subject.

[0238] The administered preparation Identity of one or more investigational drugs The identities of the investigational drugs for cohorts 1-4 are described in the following sections.

[0239] Identity of clinical trial drug 1 Respiratory syncytial virus (RSV) RSVΔNS2 / Δ1313 / I1314L (Sanofi) vaccine 5.6log 10 PFU / 0.2 mL, virus suspension.

[0240] composition Each 0.2 mL dose of RSVΔNS2 / Δ1313 / I1314L (Sanofi) vaccine contains the following components:

[0241] (i) a deletion in the 523-nucleotide NS2 gene, (ii) an amino acid deletion in the L protein (Δ1313; S1313 deletion), and (iii) a genetically stabilizing mutation in the L gene (I1314L) in attenuated live RSV, 5.6log 10 Approximately 0.1 mL of PFU is delivered to each nostril as a mist of droplets (particle size range 10-120 μm) using an intranasal atomizer device.

[0242] Preparation and administration For the administration of the experimental RSVΔNS2 / Δ1313 / I1314L(Sanofi) vaccine in this Phase I / II clinical trial, a commercially available intranasal mucosal spray (MAD) device was used. The selected device, the MAD130 system, is equipped with a spray nozzle (MAD300 atomizer), a 1 ml plastic syringe, and a plastic vial access cannula. For this Phase I / II clinical trial, the experimental RSVΔNS2 / Δ1313 / I1314L(Sanofi) vaccine prepared by the sponsor was filled into vials and stored. At the clinical trial site, the specified volume of experimental RSVΔNS2 / Δ1313 / I1314L(Sanofi) vaccine was withdrawn from the vials into a syringe, the device / nozzle was attached to the syringe head and primed, and the dose was administered intranasally by delivering approximately half of the vaccine into each nostril using the MAD130 device.

[0243] Before administration, all clinical trial drugs must be visually inspected for cracks, broken seals, incorrect labeling, and external particulate matter and / or discoloration whenever possible on the solution and container. If any of these conditions are present, the vaccine should not be administered. An alternative dose should be used, and the event should be reported to the sponsor.

[0244] Safety was ensured by observing subjects for 30 minutes after each vaccination, and any reactions during this time were documented in the CRB. In the event of anaphylactic, vasovagal, or other immediate-type allergic reactions, appropriate medical devices and emergency medications, including epinephrine (1:1000), were available at the facility.

[0245] Dosage selection and timing The subjects of Cohort 1 had RSVΔNS2 / Δ1313 / I1314L(Sanofi)5.6log on day 0. 10 I received one dose of the PFU vaccine.

[0246] The subjects in cohorts 2 and 4 received two doses, specifically on day 0, RSVΔNS2 / Δ1313 / I1314L(Sanofi)5.6log. 10 The patient received one dose of the PFU vaccine and a subsequent dose on day 56.

[0247] Vaccination device The commercially available Teleflex intranasal mucosal spray (MAD) device approved in the United States was a vaccine device. The selected device, the MAD130 system, included a spray nozzle (MAD300 atomizer), a 1 ml plastic syringe, and a plastic vial access cannula. For this Phase I / II clinical trial, the sponsor prepared experimental RSVΔNS2 / Δ1313 / I1314L(Sanofi) vaccine or control formulation, which was filled into vials and stored. At the clinical trial site, the specified volume of experimental RSVΔNS2 / Δ1313 / I1314L(Sanofi) vaccine or control formulation was withdrawn from the vial into a syringe, the device / nozzle was attached to the syringe head and primed, and the dose was administered intranasally by dispensing approximately half of the dose into each nostril using the MAD130 device.

[0248] The mechanism of action is as follows: When pressure is manually applied to the syringe, the plunger pushes the liquid formulation out of the spray nozzle, atomizing the drug formulation into a spray. The conical stopper is engineered to direct the spray plume more evenly through the nasal cavity, through the nasal valves, and up the nasal passages.

[0249] Teleflex MAD Nasal(TM) Nasal Mucosal Spray Device Manufacturing Information: Made from radiation-stable medical-grade polycarbonate material, it complies with the requirements of the United States Pharmacopeia Class VI and ISO 10993. Manufactured in an ISO Class 7 cleanroom environment. The manufacturing process complies with FDA Title 21 Section 820, ISO 13485, and EU MDD. Non-pyrogenic and latex-free. The Teleflex MAD Nasal™ intranasal mucosal spray device is ISO-594 compliant and can be used with any ISO-594 compliant Luer lock syringe.

[0250] Manufacturer's specifications: The MAD130 intranasal mucosal spray device has the following manufacturer specifications, as documented in the product insert: Typical droplet size: 30-100 μm • System dead space: 0.15 mL ·Tip diameter: 4.3mm

[0251] Identity of Clinical Trial Drug 2 Respiratory syncytial virus (RSV) RSVΔNS2 / Δ1313 / I1314L (Sanofi) vaccine 6.2log 10 PFU / 0.2 mL, virus suspension.

[0252] composition Each 0.2 mL dose of RSVΔNS2 / Δ1313 / I1314L (Sanofi) vaccine contains the following components: (i) a deletion in the 523-nucleotide NS2 gene, (ii) an amino acid deletion in the L protein (Δ1313; deletion of S1313), and (iii) a genetically stabilizing mutation in the L gene (I1314L) in attenuated live RSV, 6.2log 10 Approximately 0.1 mL of PFU will be delivered to each nostril as a mist of droplets (particle size range 10-120 μm) using an intranasal atomizer device.

[0253] Preparation and administration The preparation and administration procedures for the control formulation are the same as those described for the clinical trial drug.

[0254] Dosage selection and timing The subjects of Cohort 3 had RSVΔNS2 / Δ1313 / I1314L(Sanofi)6.2log on day 0. 10 I received one dose of the PFU vaccine.

[0255] The subjects in Cohort 4 received two doses, specifically on day 0, RSVΔNS2 / Δ1313 / I1314L(Sanofi)6.2log. 10 I received one dose of the PFU vaccine, followed by another dose on day 56.

[0256] Vaccination device Vaccine vaccination devices are described herein.

[0257] Identity of one or more control formulations placebo composition The same formulation buffer as the RSVΔNS2 / Δ1313 / I1314L (Sanofi) vaccine will be delivered, approximately 0.1 mL per nostril.

[0258] Preparation and administration The preparation and administration procedures for the control formulation are the same as those described herein for the clinical trial agent.

[0259] Dosage selection and timing Participants in Cohorts 1 and 3 received a single dose of placebo on day 0.

[0260] Participants in cohorts 2 and 4 received two doses: one placebo dose on day 0 and a subsequent dose on day 56.

[0261] Vaccination device Vaccine vaccination devices are described herein.

[0262] Pharmaceutical logistics Labeling and packaging Clinical trial formulations and placebo formulations in single-dose vials were supplied with clinical trial labeling and packaging in accordance with national regulations. Each single dose of clinical trial or placebo formulation was identified by a unique number on the main labeling surface and the outer box labeling surface. The box labeling also included a removable label for facility attachment to source documents.

[0263] Clinical trial formulations and placebo formulations will be blinded at the box level.

[0264] Shipping, storage, and inventory management of pharmaceutical products. Shipment of pharmaceutical products The clinical trial administrator or designated person contacted the principal investigator or designated person to determine the delivery date and time of the drug.

[0265] Each vaccine shipment included a temperature monitoring device to ensure the maintenance of the cold chain during transit. Upon delivery of the formulation to the facility, the receiving officer followed instructions, including checking whether the cold chain had been maintained during shipment (i.e., checking the temperature recorder). If a breach of the cold chain was suspected, the officer immediately isolated the formulation, notified the sponsor representative, and requested permission from the sponsor to use the formulation.

[0266] Storage of the preparation The principal investigator either had personal responsibility for managing the drug formulation or designated a staff member to assume that responsibility.

[0267] At the facility, the preparation must be stored in a secure location with restricted access. The vaccine was stored in a freezer below -60°C (below -76°F) under light shielding. The temperature of the vaccine must be constantly monitored and documented while it is in the research facility. In the event of an accidental break in the cold chain, the vaccine must not be administered, must be isolated, and the principal investigator or an authorized designated person must contact the sponsor representative for further instructions.

[0268] Pharmaceutical product inventory management The facility's pharmaceutical management staff managed the delivery records of the formulations to the research facility, the inventory of the formulations at the facility, the one or more doses assigned to each subject, and the disposal or return of unused doses to the clinical trial sponsor. Because the vaccine and placebo looked different, one or more unblinded coordinators verified the receipt and disbursement of the formulations and also weighed and distributed the vaccines.

[0269] The necessary information on the product label was entered into the source document and the CRB. Where applicable, the information was also entered into the relevant vaccination card.

[0270] The clinical trial sponsor's monitoring staff cross-referenced the research facility's drug dispensing records with the records of administered doses from communications from the CRB and IRT (if applicable) to verify the information.

[0271] If a shortage of the formulation under investigation was anticipated or likely to occur, the principal investigator or an authorized designated person was notified as soon as possible, and arrangements were made for the shipment of additional doses.

[0272] Alternative dosage If an alternative dosage is needed (for example, if the syringe is damaged or particulate matter is found in the syringe), facility staff must have contacted the IRT to receive a new dosage allocation.

[0273] Disposal of unused pharmaceutical products Unused or wasted formulations were returned to the clinical trial sponsor. The receipt and disbursement of formulations were tracked throughout the entire study period.

[0274] Recall of pharmaceutical products If the clinical trial sponsor decided to initiate the recall process, one or more principal investigators informed the sponsor of what needed to be done.

[0275] Blinding and unlocking procedures This study was conducted using an observer-blinded method: The principal investigators and researchers conducting the safety evaluation, as well as the subjects, were unaware of which vaccine was administered. Only researchers who prepared and administered the vaccine, and who were not involved in the safety evaluation, knew which vaccine was administered.

[0276] The parents / guardians / decision-makers who collected safety data, the veterinary and research personnel responsible for the study, and the laboratory staff who analyzed the blood samples did not know which formulation was administered. The vaccinated individuals were responsible for the preparation and administration of the formulation and were not authorized to collect any safety data. In addition, the vaccinated individuals or authorized designated persons ensured that the randomization documents were stored in a secure location accessible only to them.

[0277] In the event of an adverse event (AE), the code may be unlocked only if identifying the vaccine received could affect the treatment of the individual. Code unlocking must be limited to the individual or group of individuals in whom the AE is observed.

[0278] Blinding can be lifted by the principal investigator or their authorized representative through the IRT system. Once the site has responded to the emergency, the principal investigator or their authorized representative must notify the sponsor RMO whether the code in question has been unlocked. All attempts to contact the sponsor prior to lifting the blinding should be documented in the source documents, and the code unlocking CRF should be completed.

[0279] A code unlocking request is also If a SAE occurs as described in International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH) E2A, the GPV department may report it to the health authorities through an internal system. In this case, the code will only be unlocked for the one or more subjects involved. The information obtained from unlocking (i.e., the vaccine or group allocation of the subjects) will not be communicated to the principal investigator or the immediate team involved in the study, nor will it be communicated to the GPV representative. If necessary, the safety assessment may be carried out by an ad-hoc IDMC to facilitate the process.

[0280] The IEC / IRB must be notified of any code decryption. All documents related to the event must be retained in the facility's research records and the sponsor's files. Intentional or unintentional code decryption must be reported, documented, and explained, and the name of the person who requested it must be provided to the sponsor.

[0281] An open-label interim analysis for dose selection of the RSVΔNS2 / Δ1313 / I1314L(Sanofi) vaccine was planned for subjects from cohorts 1, 2, and 3, and at least 90 subjects enrolled in cohort 4. This interim analysis was conducted when subjects provided safety data up to time D84 and immunogenicity results for D84 became available. This open-label interim analysis required deblinding of data; blinding at the subject and investigator levels was maintained by implementing special procedures.

[0282] Tests performed within the scope of the sponsor's laboratory and its contracted laboratories were blinded for the allocation of study treatment groups. One or more codes relating the information on the sample vials to the allocation of study treatment groups were held by the clinical department and were not available to staff of the sponsor or contracted laboratories.

[0283] Randomization and allocation procedure Upon arrival at the hospital, an IRT (Initial Treatment Response) is performed to assign a target number, and patients are then allocated to vaccine groups based on their dosage.

[0284] At the time of visit 01, subjects who met the inclusion / exclusion criteria and signed the ICF, along with their parents / guardians / decision-makers, were randomly assigned to one of the vaccine groups according to the cohort: • RSVΔNS2 / Δ1313 / I1314L(Sanofi) 5.6log for the ratio of cohorts 1 and 2:1:1 10 PFU (RSV low dose) or placebo • RSVΔNS2 / Δ1313 / I1314L(Sanofi) 6.2log for a 3:1:1 cohort ratio 10 PFU (high dose of RSV) or placebo • RSVΔNS2 / Δ1313 / I1314L (Sanofi) 6.2log for a cohort ratio of 4:1:1:1 10 PFU (RSV high dose) or RSVΔNS2 / Δ1313 / I1314L (Sanofi) 6.2 log 10 PFU (RSV low dose) or placebo

[0285] At the time of arrival at the hospital, randomization was stratified by cohort and age subgroup (under 12 months old / 12 months old and over).

[0286] Facility staff connected to the IRT, entered identification and safety information, and responded to IRT prompts to confirm the minimum amount of data. The IRT then provided dose allocations, which were confirmed by facility staff. If a participant was not eligible to participate in the study, the information was simply recorded in the participant recruitment log.

[0287] The target number assigned by the IRT consisted of a 12-digit string (3-digit country identifier, 4-digit research facility identifier, and 5-digit target identifier). For example, target 840000100005 is the 5th target registered with facility number 1 in the United States (840 is the US country code).

[0288] Adherence to treatment The following measures ensured that the administered vaccine dose adhered to the planned dose, and that any non-compliance was documented so that it could be considered in data analysis: • All vaccinations were administered by qualified researchers. The facility's pharmaceutical management staff managed records of the delivery of pharmaceuticals to the research facility, the inventory of pharmaceuticals at the facility, the one or more doses assigned to each subject, and the disposal of unused or wasted doses.

[0289] Concomitant medications and other therapies At the time of registration, the source document must record any medications and other therapies currently being used (e.g., blood products), as well as any new medications prescribed for new medical conditions / exceptions during participation in the study.

[0290] Documentation to the CRB regarding concomitant medications being used was limited to the specific classification of one or more targeted medications that began on the date of the initial vaccination. This may include targeted medications that were started before the date of vaccination.

[0291] From the date of each vaccination until the end of the follow-up period, based on both requested and spontaneous reporting, the drugs subject to reporting were collected by the CRB.

[0292] Reportable drugs include those that affect, or may affect, the integrity of safety information collected after any vaccination and / or the immune response to the vaccine. There are three standard classifications for reportable drugs: Drugs that may affect or could affect safety assessments (e.g., antipyretics, analgesics, and non-steroidal anti-inflammatory drugs [NSAIDs], steroids / corticosteroids). • Drugs that affect or may affect the immune response (e.g., other vaccines, blood products, antibiotics that may interfere with bioassays used by the GCI division, steroids / corticosteroids, immunosuppressants, immunomodulatory drugs with immunosuppressive properties, antiproliferative drugs such as DNA synthesis inhibitors) This is defined. Drugs that affect, or may affect, both safety and immune response (e.g., steroids / corticosteroids)

[0293] The information reported to the CRB for each reported drug is: ·Trade name • Reason for prescription: Prevention / Not prevention. Record one or more medications prescribed for AE prevention in the "Action Taken" section of the AE collection form. • Start and end dates ·Reason for treatment It was limited to that.

[0294] Dosage and route of administration, homeopathic drugs, topical and inhaled corticosteroids, and topical, ocular, and ear treatments were not recorded. Topical analgesics were not applied to the vaccination site; however, if they were inadvertently applied to the vaccination site, in this specific case, they were recorded as a Category 1 drug.

[0295] Drugs administered in response to an adverse event (AE) were recorded only in the "Action Taken" section of the AE CRF. Unless one or more of the administered drugs belonged to one of the pre-listed categories, details were not recorded in the concomitant drug CRF.

[0296] The drugs were coded.

[0297] Prohibited combination drugs The following uses are prohibited: • During the acute phase (28 days after administration of the clinical trial drug), prophylactic antipyretics, decongestants, or antihistamines—note that the use of these drugs to treat symptoms is permitted. • Clinical trial drugs or vaccines other than the clinical trial drug administered within 56 days of the administration of the clinical trial drug.

[0298] Preventive concomitant medications Due to the potential for confounding effects on immunogenicity, the following treatments should be avoided after administration of the investigational drug, unless clinically indicated: • Systemic corticosteroids or other immunomodulators administered at doses exceeding 2 mg / kg or equivalent to 20 mg of prednisone daily for more than 14 days. • Immunoglobulin and / or any blood product.

[0299] After administration of the investigational drug, the following should be avoided, except in cases where it is indicated during a pandemic: • An approved inactivated vaccine or attenuated live rotavirus vaccine administered within 14 days of the administration of the clinical trial drug. • Approved live viral vaccines other than rotavirus vaccine within 28 days of administration of the clinical trial drug

[0300] Sample management Blood samples for antibody response assessment were collected at visits 01, 03, and 04 for subjects in cohorts 1 and 3 who received one dose, and at visits 01, 03, 05, and 06 for subjects in cohorts 2 and 4 who received two doses. For details on the sample collection schedule, please refer to the research procedure table in this specification.

[0301] Nasal swab samples for RSV confirmation were collected at visit 02 (day 7) for subjects in cohorts 1 and 3 who received one dose, and at visit 04 (day 63) for subjects in cohorts 2 and 4 who received two doses. Nasal swab specimens for detecting RSV and respiratory pathogens were collected from subjects at the time of their first hospital visit.

[0302] All sample collection in the United States complied with the Centers for Disease Control and Prevention (CDC) recommendations, "Interim Infection Prevention and Control Recommendations for Patients with Suspected or Confirmed Coronavirus Disease 2019 (COVID-19) in Healthcare Settings." Sample collection at facilities outside the United States complied with local regulatory guidelines regarding COVID-19.

[0303] For detailed information on the sample collection schedule, please refer to the research procedure table in this specification.

[0304] Sample collection During the aforementioned hospital visit, up to 5 mL of blood was collected in a tube provided or recommended by the clinical trial sponsor.

[0305] During the aforementioned hospital visits, nasal swab samples were collected and transferred to tubes provided or recommended by the clinical trial sponsor. The staff collecting the samples employed sufficient infection prevention and control measures.

[0306] Immediately before blood collection or nasal swab collection, the staff member performing this procedure confirmed the subject's identification information, the assigned subject number, and the sample collection stage indicated on the pre-printed label and the label attached to the tube.

[0307] Sample preparation serum sample Here is an overview of the procedure.

[0308] After blood collection, the tube should be placed vertically and left undisturbed for a minimum of 1 hour and a maximum of 24 hours to allow the blood to coagulate. The sample can be stored at room temperature for a maximum of 2 hours; if stored for longer than 2 hours, the sample must be refrigerated at a temperature of +2°C to +8°C (+35.6°F to +46.4°F) after the coagulation time at room temperature and centrifuged within a maximum of 24 hours.

[0309] Next, the sample is centrifuged and the serum is transferred to an appropriate number of aliquot tubes. These tubes are pre-labeled with adhesive labels indicating the study code, subject number, and sample collection stage or number of visits.

[0310] The sample identification list should specify the subject number, the date of sample collection, the number of aliquots obtained, the date of preparation, and the subject's consent for future use of the sample, and should be recorded in the source document. A margin should be provided on this list for annotations regarding the quality of the sample.

[0311] Nasal swab sample An outline of the procedure is provided herein.

[0312] The subject's identification number, any other necessary information, the sample collection date, and the preparation date were clearly documented.

[0313] Sample storage and shipping serum sample During storage, serum tubes should be kept in a freezer set and maintained at a temperature of -20°C (-4°F) or below. Temperature was monitored throughout the study and documented in an appropriate format. If the temperature rose above -10°C (14°F) for any period of time, the clinical logistics coordinator was notified.

[0314] Shipments to laboratories were carried out only after appropriate monitoring and in accordance with the instructions of the clinical logistics coordinator. Serum was shipped frozen in packaging containers provided by the carrier, kept frozen using dry ice. Temperature monitoring was also performed in this case. Shipments must comply with the United Nations (UN) Class 6.2 standard and the International Air Transport Association (IATA) 602 packaging instructions.

[0315] The samples were sent to Sample, Reagent, & Animal Services within R&D Global Operations at the clinical trial sponsor.

[0316] Nasal swab sample The nasal swab samples were placed in packaging containers provided by the shipping company, kept frozen using dry ice, and shipped frozen.

[0317] Use of stored biological samples for future research Any unused serum and nasal swab samples were safely stored at the sponsor's facility for at least 25 years after the completion of the study. These samples are retained for long-term storage to help respond to regulatory inquiries regarding product approval and to potentially reconfirm the validity of the study results. In addition, these samples will also be used in assay development activities for RSV or other respiratory pathogens.

[0318] Other biological samples collected to qualify subjects for inclusion in the study or to monitor their health are intended for immediate use. If these samples are not used, they are destroyed no later than the end of the study or after the time required by local law.

[0319] In addition, parents / guardians / legal representatives were asked if they could instruct the ICF whether they would authorize the future use of any unused stored serum samples for other tests. If permission was denied, the sample was not used for any tests unless directly related to this study. If consent was given, permission was granted free of charge. The anonymity of the samples was ensured. The purpose of any possible future research is currently unknown and may not be related to this particular study. Knowledge of vaccines or infectious diseases may improve, existing tests for determining vaccines may improve, or new tests may be developed. Human genetic testing will never be performed on these samples without specific, individual informed consent.

[0320] Clinical trial supplies The clinical trial sponsor supplied the research facility with protocols, ICF, CRB, SAE reporting forms, daily cards, memory aids, and other research documents, as well as the following research materials, namely all research vaccines including vaccine administration devices, blood collection tubes, cryotubes, cryotube storage boxes, cryotube labels, temperature recorders, shipping containers, and digital thermometers.

[0321] The means of performing electronic data capture (EDC) were defined by the sponsor. If a computer was provided by the sponsor, it was collected at the end of the study.

[0322] The principal investigator supplied all vaccine supplies, venotomy equipment, and centrifugation equipment, including biohazard and / or safety supplies. These included needles and syringes, laboratory gloves, lab coats, sharp object waste containers, and absorbent paper towels. The facility ensured that all biohazard waste was autoclaved and disposed of according to local practices. The principal investigator also supplied adequate space for storing the formulations and blood samples in a temperature-controlled refrigerator, and adequate space for serum aliquots in a temperature-controlled freezer.

[0323] If additional supplies were needed, the researchers contacted the clinical trial sponsor and instructed them on the required quantities.

[0324] Evaluation items and evaluation method Primary evaluation criteria and evaluation method safety Safety definition The following definitions are quoted from the ICH E2A guideline, "Clinical Safety Data Management: Definitions and Standards for Expedited Reporting."

[0325] Adverse events (AEs): An adverse event (AE) is any undesirable medical event that occurs in a patient or research subject receiving a drug, but is not necessarily causally related to the treatment in question. Therefore, an AE can be any undesirable, unintended sign (including, for example, abnormal laboratory findings), symptom, or disease that is temporally related to the use of that drug, regardless of whether it is thought to be related to the drug or not.

[0326] Therefore, AE is, • New diseases • Worsening of existing medical conditions • The effectiveness of vaccination, including the control drug. • The above combinations It is possible.

[0327] All adverse events (AEs) include both serious and non-serious AEs.

[0328] Surgical procedures are not AEs; surgical procedures are procedures performed to treat medical conditions. An AE (if it occurs during the study period) is the medical condition that leads to the procedure being performed.

[0329] Pre-existing medical conditions should not be reported as AEs. However, if a pre-existing medical condition worsens in frequency or severity after the study intervention, or if there is a change in its clinical severity according to the principal investigator, that change should be reported as an AE (exacerbation). This also applies equally to recurrent episodes of pre-existing conditions (e.g., asthma) if they increase in frequency or severity after vaccination.

[0330] Serious adverse events (SAEs): Critical and severe are not synonymous. The term severe is often used to describe the intensity of a particular event as corresponding to Grade 3. This is not the same as critical, which is based on a subject / event outcome or usually the treatment criteria associated with the event that threaten the life or function of the subject. Critical, not severity, serves as a guideline when defining regulatory reporting obligations.

[0331] SAEs can be administered at any dose. • Causes death • Threatening life • Requires hospitalization or extension of existing hospitalization • Leads to persistent or significant disability / incapacity • Congenital anomaly / birth defect • It is an important medical event (IME). It is one of those troublesome medical events.

[0332] The term "life-threatening" refers to an event in which there was a risk of death for the subject at the time of the event; this does not refer to an event that, hypothetically, would have caused death if it had been more severe.

[0333] Except for planned hospitalizations or outpatient treatments that did not involve hospitalization prior to enrollment in the study, all medical events leading to hospitalization were documented and reported as SAEs.

[0334] "Persistent or significant disability / incapacity" means a substantial breakdown in a person's ability to perform normal daily living functions.

[0335] Medical and scientific judgment should be exercised in determining whether rapid reporting is appropriate in other situations, such as IMEs that do not immediately threaten life or lead to death or hospitalization, but may endanger the subject's health or require intervention to prevent one of the other outcomes defined above. These IMEs should also generally be considered serious. Examples of such events include allergic bronchospasm requiring emergency room or home intensive care, hematopoietic dysfunction or seizures not requiring hospitalization, onset of drug dependence or abuse, new-onset diabetes, or autoimmune disease.

[0336] Adverse reactions: Any harmful, unintended reaction to a drug in any given dose must be considered an adverse reaction (AR). (The term "reaction to a drug" means that there is at least a reasonable possibility of a causal relationship between the drug and the adverse event (AE).)

[0337] The following additional definitions may be used by the clinical trial sponsor:

[0338] Immediate-type events / responses: Immediate events are recorded to capture medically relevant, spontaneously reported systemic adverse events (including those related to the administered drug) that occur within the first 30 minutes after vaccination.

[0339] Responses from involuntary reports based on requests: Involuntary, request-based reactions are "expected" adverse reactions (signs or symptoms) observed and reported under the conditions (nature and occurrence) specified in the protocol and CRB (e.g., fever and runny nose occurring between Day 0 and Day 28 after vaccination).

[0340] By definition, responses resulting from involuntary reporting based on requests should be considered to be related to the administered drug.

[0341] For vaccines administered intranasally, involuntary reports based on requests may be either injection-site reactions or systemic reactions.

[0342] AE / AR based on spontaneous reporting: Spontaneous reported AEs are observed AEs that do not meet the conditions specified in the CRB regarding the diagnostic and / or occurrence window after vaccination. For example, if a fever between D0 and D28 is a requested, involuntary reported response (i.e., as specified in the protocol and CRB), then a fever beginning on D28 is a requested, involuntary reported response, while a fever beginning on D29 after vaccination is a spontaneously reported AE. Spontaneous reported AEs include both serious (SAEs) and non-serious spontaneously reported AEs.

[0343] AEs (MAAEs) that led to seeking medical attention: MAAEs are new onsets or exacerbations of conditions that prompt a subject or their parent / guardian / decision-maker to seek unscheduled physician consultation at a clinic or emergency department. Consultations conducted by telephone or email were considered clinic visits for the purpose of collecting MAAEs. This definition excludes pre-scheduled clinic visits for routine checkups, as well as pediatric health checkups or follow-up visits for chronic conditions that occurred before enrollment in the study. AEs discovered during scheduled routine visits (e.g., upper respiratory tract infections, otitis media) were collected as MAAEs.

[0344] Injection site reaction: The administration site reaction is an AR (arthria) at the administration site and its surrounding area, i.e., the nasal mucosa. This reaction is considered to be related to the administered drug.

[0345] Systemic AEs: Systemic AEs are any AEs that are not injection or administration site reactions. These include systemic symptoms such as headache and fever, as well as localized or localized symptoms unrelated to the vaccination or administration site (e.g., localized conjunctivitis that does not occur at the administration site).

[0346] Particularly noteworthy adverse events (AESIs): Adverse events of particular interest are those specific to the investigational product or program under ongoing monitoring, and prompt communication by the principal investigator to the sponsor is a scientific and medical concern. Such events may warrant further investigation to characterize and understand them. Depending on the nature of the event, prompt communication by the sponsor of this study to other parties (e.g., regulatory authorities) may also be appropriate. AESIs include both serious (SAEs) and non-serious spontaneously reported AEs.

[0347] The following definitions describe different stages of safety follow-up after vaccine administration:

[0348] Acute phase: The acute phase begins with the vaccine administration on day 0 and ends at midnight on day 28 (day 28) after the vaccine administration. The acute phase of the second vaccine administration begins on day 56 after vaccination and ends at midnight on day 84.

[0349] During the acute phase of this study, research medical personnel were available 24 hours a day by telephone to answer questions from parents / guardians / legal representatives regarding any illnesses that may occur during this period. Researchers contacted parents / guardians / legal representatives daily for the first seven days after each vaccine administration, and then three times a week from day 7 to day 28 after each vaccine administration. This 28-day acute phase of safety follow-up coincided with the shedding period of attenuated live RSV virus in RSV seronegative infants and toddlers. If a parent / guardian / legal representative reported a SAE, a safety event meeting the criteria for temporary suspension or termination of the study as described herein, or symptoms suggestive of respiratory illness, they were to schedule an onset visit as described herein. During the acute phase, the eDC enabled daily safety monitoring of study participants and was programmed to send alerts to parents / guardians / legal representatives and the research facility if symptoms suggestive of respiratory illness were present.

[0350] Acute phase and subsequent phase: For subjects who received one dose, the acute post-operative period begins at 0:01 AM on D29 and ends at 0:00 AM on D56. For subjects who received two doses, the first acute post-operative period begins at 0:01 AM on D29 and ends at 0:00 AM on D56, except when the second dose is exactly on D56, in which case it ends immediately before the second dose is administered. For subjects who received two doses, the second acute post-operative period begins at 0:01 AM on D85 and ends at 0:00 AM on D112.

[0351] During the acute and follow-up phases of this study, parents / guardians / decision-makers were instructed to monitor their children for any symptoms suggestive of serious adverse events and to contact researchers if any were observed. If a parent / guardian / decision-maker reported a SAE or safety event that met the criteria for temporary suspension or termination of this study as described herein, a schedule for hospital visits for the onset of the illness must be arranged.

[0352] Safety evaluation items The primary endpoints for safety assessment are as follows (in all infants and toddlers, regardless of baseline serological status): • In each case, the occurrence of systemic adverse events (AEs) was reported spontaneously within 30 minutes of vaccination. • For each vaccine, the occurrence of administration site reactions and systemic reactions (i.e., those listed in advance for the target DC / eDC and CRB) based on requested, involuntary reports within 28 days after each vaccination (i.e., during the acute phase). • In all cases of vaccination, there is no risk of spontaneous reporting (reported by the individual) of any adverse event (AE) within 28 days of vaccination (i.e., during the acute phase). • Any AESI (Anaesthesia-mediated Stress Syndrome) occurring within 28 days of vaccination for any type of vaccine. • Any MAAE (Mean Emergency Affected) occurring within 28 days of vaccination for any type of vaccine. • Occurrence of any type of SAE throughout the entire study period. Other safety evaluation items were recorded or prepared as described in the statistical analysis plan. Depending on the item, these may include nature (Medical Dictionary for Regulatory Activity (MedDRA) basic terminology), time of occurrence, duration, number of days, intensity, relationship with vaccine, treatment performed, whether the AE led to early termination of this study, severity, or outcome.

[0353] Safety evaluation method At each vaccination, in-person, or remote visit, the principal investigator or their authorized representative either conducted a focused physical examination (in-person consultation) or interviewed the parent / guardian / decision-maker regarding any involuntary and spontaneously reported reactions and adverse events (AEs) recorded on the daily card / electronic daily card, as well as any other AEs that may have occurred since the previous visit. All relevant data were transcribed into the clinical record book (CRB) in accordance with instructions provided by the sponsor.

[0354] This study monitors the safety, infectivity, replication, and immunogenicity of both doses of RSVΔNS2 / Δ1313 / I1314L (Sanofi), paying attention to vaccine virus infectivity and replication (i.e., participant viral shedding rate and vaccine virus titer in nasal swabs) 7 days after vaccination 1 and 2, which are the easiest measures to quantify regarding vaccine virus attenuation levels.

[0355] Observation period immediately after vaccination Safety was ensured by observing subjects for 30 minutes after each vaccination. Post-vaccination observations must be documented in the source material. Any adverse events (AEs) occurring during this period were noted in the source material and recorded in the CRB as follows: • Spontaneous systemic adverse events (AEs) were recorded in the CRB as immediate AEs (marked "present" to indicate presence or absence, and details were collected). • Involuntary and spontaneous reports of administration site reactions, as well as involuntary reports of systemic reactions, were recorded in the CRB starting from the vaccination date, in the same manner as voluntary reactions. • The SAE was recorded in the CRB and reported to the sponsor like any other SAE.

[0356] Reactiongenicity (reactions based on involuntary reports requested from day 0 to day 28 after each vaccination) After each vaccination, the parent / guardian / legal representative of the subject was provided with a DC / eDC and a digital thermometer, and instructions were given on how to use them. The subject recorded the following items on a daily card / electronic daily card on the day of vaccination and for the following 28 days (i.e., from day 0 to day 28) until resolved: • Daily body temperature and the route used to measure it • Daily measurements and intensity grades of administration site reactions (e.g., runny nose) and systemic reactions (e.g., fever) based on involuntary reporting at the request of any reason. • Treatments performed for each event (e.g., drug therapy)

[0357] One or more actions taken by a parent / guardian / decision-maker to treat and / or manage a response resulting from an involuntary report based on some request are classified in the CRB using the following list (all applicable items must be checked): ·none • Drug therapy • Visiting a healthcare provider ·hospitalization • Discontinuation of research-based vaccine administration

[0358] The parents / guardians / decision-makers in the study received telephone calls daily for the first seven days after vaccination, and then three times a week after their D07 visit, to remind them to be sure to record all safety information on their daily card / electronic daily card.

[0359] If a phone call was to be made on a weekend or holiday, the call had to be made on the next business day. If the call was not made on the designated day, the researcher continued calling until contact was made. All attempts to make a phone call and their results were documented in the source material.

[0360] Tables 6 and 7 present the administration site reactions listed in advance on the daily card and CRB, respectively, along with their intensity scales.

[0361] [Table 21]

[0362] [Table 22]

[0363] [Table 23]

[0364] Important notes for accurate body temperature determination: Parents / guardians / representatives measured body temperature once a day, preferably at the same time each day. The optimal time for measurement was the evening, when body temperature is highest. Body temperature was also measured at times when a fever appeared. The observed daily body temperature and measurement route were recorded on a daily card, and the highest temperature was recorded on a CRB by the facility. The preferred route for this study was rectal. Body temperature before vaccination was also systematically collected in the source data by the principal investigator. Ear thermometers should not be used.

[0365] Spontaneous reported adverse events In addition to recording responses based on requested, involuntary reports, parents / guardians / decision-makers were instructed to record any other medical events that may occur during the 28-day period following each vaccination. A section for this purpose was provided on the daily card.

[0366] Information regarding SAEs was collected and assessed throughout this study, from registration to the final hospital visit. Any SAEs occurring at any point during the study were reported by the principal investigator to the CRB in accordance with the instructions provided by the sponsor; this included checking the “Serious” box on the AE CRF and completing the appropriate safety supplement CRF. All information regarding SAEs was reported either as part of the initial report or in follow-up reports if relevant information (e.g., outcomes, medical history, laboratory results, copies of admission reports, and oral autopsy questionnaires, if used) became available later. If a subject experienced a febrile convulsion (a neurological event involving fever and seizures), the event was assessed and considered an SAE in accordance with the “Guideline for definition and collection of cases of febrile convulsion.”

[0367] For each spontaneously reported adverse event (AE), regardless of whether it was severe or not, the following information was recorded: • Start and end dates (end dates for all relevant AEs were obtained from proactively requested involuntary reporting. For other events, the principal investigator provided the end date when it became available. AEs for which an end date could not be obtained during the course of the study were considered ongoing at the end of the study). • Intensity of the event: a. Fever temperatures were collected and analyzed based on corresponding scales used for involuntary, request-based reporting responses. b. All other spontaneously reported AEs were classified according to the following intensity scale: i. Grade 1: An adverse event of a type that is usually transient and may require only minimal treatment or therapeutic intervention. This event generally does not interfere with normal daily activities. ii. Grade 2: Adverse events of a type that are usually mitigated by additional therapeutic interventions. These events interfere with normal daily activities and cause discomfort, but do not pose a serious or permanent risk of harm to the study participant. iii. Grade 3: An adverse event of a type that interrupts normal daily activities, has a significant impact on the clinical condition, or may require intensive therapeutic intervention. • Whether the adverse event (AE) was related to the investigational drug (regarding spontaneously reported systemic AEs) The principal investigator determined that there was either "no relationship" or "a relationship" between the adverse event (AE) and the investigational drug, as described herein. • Treatments performed for each adverse event (e.g., drug therapy) One or more actions taken by a parent / guardian / decision-maker to treat and / or manage any spontaneously reported adverse event (AE) were classified in the CRB using the following list (all applicable items must be checked): ·none • Drug therapy • Visiting a healthcare provider ·hospitalization • Discontinuation of research-based vaccine administration • Whether AE was AESI, MAAE, and / or SAE.

[0368] For each SAE, the principal investigator documented all applicable severity criteria (relationship to outcome, time, and study procedure). • Was the research discontinued due to adverse events (AEs)?

[0369] Adverse events that led to a visit to a medical institution Any MAAEs (Medical Emergency Events) that occurred within the first 28 days after vaccination (D0-D28 for all subjects in cohorts 1, 2, 3, and 4, and D56-D84 for subjects in cohorts 2 and 4) were collected using the same process as for other AEs. Acute respiratory illness (MAARI) and acute lower respiratory tract illness (MAALRI) events that led to medical consultation and occurred within this time frame and outside of the RSV surveillance epidemic period were classified as MAAEs.

[0370] Particularly noteworthy adverse events (AESIs) Any AESIs that occurred within the first 28 days after vaccination (D0-D28 for all subjects in cohorts 1, 2, 3, and 4, and D56-D84 for subjects in cohorts 2 and 4) were collected using the same process as for other AEs.

[0371] All particularly noteworthy adverse events in this study may be graded according to the Division of AIDS (DAIDS) severity grading system for adult and pediatric adverse events, except for acute wheezing, which may be graded according to the Brighton Collaboration wheezing severity grading system. The following particularly noteworthy adverse events were derived from previous NIH research experience with similar candidates and were assessed in this study: ·Acute otitis media ·URI • Pharyngitis • Cough without LRI ·LRI Strider • Ra sound ·Tachypnea • Acute wheezing ·pneumonia • Laryngeal tracheobronchitis

[0372] Acute otitis media: Loss of tympanic membrane landmarks, accompanied by redness and loss of mobility. May or may not be accompanied by fever or other respiratory symptoms. Confirmed by tympanometry, if possible. This diagnosis must be made by a medical professional.

[0373] Pharyngitis: Pharyngeal redness with exudate or pharyngeal redness with tender, swollen lymph nodes. Note: This may also be associated with sore throat, or dysphagia or difficulty swallowing. This diagnosis must be made by a healthcare professional.

[0374] Cough without LRI: The child experiences three or more episodes of coughing, or awakens from sleep due to coughing, during an observation period of 15 minutes for two or more consecutive days. The coughing must not be accompanied by a lower respiratory tract disease. This diagnosis must be made by a medical professional. Note: This does not apply to coughing related to eating or choking.

[0375] Strider: A rough, mid-range inspiratory sound often accompanied by croup-like cough and hoarseness, associated with obstruction of the laryngeal region or extrathoracic trachea. This diagnosis must be made by a medical professional.

[0376] R sound: Abnormal lung sounds heard with a stethoscope. Ralphs can be sibilant (wheezing), dry (resonant), or wet (with a strong crackling sound), depending on the volume and density of fluid circulating in the airways. They must persist for at least 20 minutes and require assessment and diagnosis by a medical professional, and confirmation by another medical professional if possible.

[0377] Tachypnea: An increase in respiratory rate to over 40 breaths per minute in infants aged 6-12 months, and toddlers aged 1-3 years who are just learning to walk, to over 30 breaths per minute. This diagnosis must be made by a medical professional.

[0378] Acute wheezing: According to the Brighton Collaboration case definition, acute wheezing is defined as having the following level of diagnostic certainty: • The onset occurs suddenly and without warning, leading to a significant change in the subject's previously stable condition, and • Breath sounds that can be heard by auscultation, and • It can be heard during exhalation, and the sound is mainly exhaled, but in severe cases, there may be inspiratory components different from the strider. A clinical sign defined by, The following criteria define the level of certainty in the diagnosis: Level 1 Based on the digital stethoscope recording compared to the reference audio file, it is classified as wheezing, or • The wheezing must be classified as such by two specially trained healthcare providers, such as a respiratory physician or someone who has received formal auscultation training based on standard wheezing training tools. Level 2a (One specially trained healthcare provider) • The wheezing is classified by a specially trained healthcare provider, such as a respiratory physician or someone who has received formal auscultation training based on standard wheezing training tools, and • There is an immediate response to bronchodilator therapy, i.e., no wheezing after treatment, or improvement in wheezing severity as documented by the healthcare provider. Level 2b (2 healthcare providers) • The patient was classified as having wheezing by two untrained healthcare providers, i.e., neither of whom were respiratory physicians nor had received formal auscultation training based on standard wheezing training tools, and • There is an immediate response to bronchodilator therapy, i.e., there is no wheezing after treatment, or the wheezing severity documented by the healthcare provider has improved, or • The infant has been diagnosed with acute bronchiolitis. Level 3 (existing diagnosis) • Classified as wheezing by a single healthcare provider or caregiver (e.g., parent / guardian / decision-maker) who has not received special training, and • There is an existing medical diagnosis that the patient has a respiratory illness in which wheezing is the primary symptom. These are clinical signs characterized by [the following].

[0379] The complete Brighton Collaboration case definition is provided here, but diagnostic certainty level 3 is not required for this study, and children with a pre-existing diagnosis of wheezing will not be enrolled in this study.

[0380] pneumonia: Ralphs and intermittent rales lasting more than 20 minutes originate in the lower respiratory tract, are usually accompanied by tachypnea, and do not disappear with coughing. This can be confirmed by the presence of fused shadows on X-ray. Clinical evaluation and diagnosis must be performed by a healthcare professional and, if possible, confirmed by another healthcare professional.

[0381] Laryngeal tracheobronchitis (croup): Coughing, hoarseness, and inspiratory stridor that persist for more than 20 minutes should be assessed and diagnosed by a healthcare professional and, if possible, confirmed by another healthcare professional.

[0382] Table 8 presents the DAIDS severity scale for AESI excluding wheezing, with grades 1-4.

[0383] [Table 24]

[0384] All deaths related to AESI shall be classified as Grade 5.

[0385] Table 9 presents the Brighton Collaboration severity grading system for wheezing.

[0386] [Table 25]

[0387] Determining causality The principal investigator assessed the causal relationship between each spontaneous systemic adverse event (AE) and the administered product as either no relationship or a relationship, based on the following definitions: • No correlation - The AE is clearly / almost certainly caused by another etiology, such as an underlying disease, therapeutic intervention, or combination therapy; or the delay between vaccination and the onset of the AE is not consistent with a causal relationship; or the AE began before the first vaccination. • Related - This means there is a "reasonable possibility" that the adverse event (AE) was caused by the administered drug, i.e., there is evidence or arguments suggesting a causal relationship.

[0388] Note: By convention, all adverse events (AEs) reported at the administration site (whether requested, involuntary, or spontaneous) and all requested, involuntary systemic AEs are considered to be related to the administered drug and are therefore referred to as reactions, and no opinion from the principal investigator regarding the relevance is required.

[0389] Adverse events that persisted at the end of this study and were likely related to the formulation, regardless of their severity, were followed up by the principal investigator until they completely disappeared or the patient's condition stabilized. The principal investigator informed the sponsor of the date on which the event finally disappeared or when "chronicity" was established.

[0390] infectious power There is no primary purpose regarding infectivity.

[0391] immunogenicity Definition of immunogenicity RSV serological status For this Phase I / II trial, serum IgA detection was selected as a biomarker for RSV infection in infants and toddlers. The serological status of IgA, i.e., RSV-uninfected and RSV-infected, was defined as serum anti-RSV A IgA antibody being undetectable or detectable, respectively.

[0392] Serological status assessment of RSV IgA The RSV IgA ELISA used to determine the serological status will be performed by the clinical trial sponsor or by a contract laboratory authorized by the sponsor.

[0393] The methods used to measure the serological status of IgA are summarized below.

[0394] Explanation of RSV IgA measurement method IgA antibodies against the RSV F antigen are measured using an anti-RSV F IgA ELISA. The RSV F protein antigen is coated onto the surface of a microtiter plate. The plate is blocked, and any unadsorbed coated antigen is washed from the wells. Serially diluted human serum samples (test sample, reference, and quality control) are incubated in the wells. Anti-RSV F protein-specific antibodies in the serum samples bind to the immobilized RSV F protein antigen. Unbound antibodies are washed from the wells, and horseradish peroxidase (HRP) conjugate goat anti-human IgA enzyme conjugate is added. This conjugate binds to the antigen-antibody complex. Excess conjugate is washed away, and a colorimetric substrate is added. The bound enzyme catalyzes a hydrolysis reaction, thereby causing color development. The intensity of the color development is proportional to the amount of antigen-specific IgA antibody bound to the well. The results are read using a spectrophotometer.

[0395] The concentration of IgA antibody against RSV F antigen is calculated using six 2x series dilutions, and the values ​​are converted to ELISA units (EU) / mL.

[0396] Immunogenicity evaluation items The primary endpoint for evaluating immunogenicity is: • For RSV-uninfected subjects, the RSV A serum neutralizing antibody titers are measured up to D56 for cohorts 1, 2, 3, and 4, and up to D84 for cohorts 2 and 4.

[0397] Subjects with a history of RSV infection and those who have not been infected with RSV are defined herein.

[0398] Immunogenicity determination method By evaluating the immunogenicity of the vaccine candidate, RSV A serum neutralizing antibody titers were measured (by microneutralization assay).

[0399] RSV neutralizing antibody determination The RSV microneutralization (MN) assay was performed by the clinical trial sponsor or by a contract laboratory authorized by the clinical trial sponsor.

[0400] The MN method to be used is summarized below. Development and qualification of this method have been completed; this method will be validated before the Phase III clinical trial.

[0401] Explanation of the RSV MN method RSV neutralizing antibodies were measured using the MN assay. A 2-fold series dilution of serum (pre-heat-inactivated) under test was mixed with a constant concentration of RSV-A2 strain (ATCC VR-1540). This mixture was inoculated into the wells of a 96-well microplate with tolerant HEp-2 cells (ATCC CCL-23) and incubated for 2 days. The decrease in viral infectivity (amount of viral antigen produced) due to neutralization by antibodies present in the serum sample was detected by enzyme-linked immunosorbent assay (ELISA). After washing and fixation, the amount of RSV antigen produced in the cells was detected by continuous incubation with RSV-specific mAb, horseradish peroxidase anti-mouse IgG conjugate, and chromogenic substrate. The resulting optical density was measured using a microplate reader. A decrease in RSV infectivity compared to the virus control well corresponds to a positive neutralization reaction, indicating the presence of neutralizing antibodies in the serum sample.

[0402] Secondary evaluation items and evaluation methods safety Safety definition The definition of safety is presented above.

[0403] Safety evaluation items Secondary evaluation items for safety assessment are: • For cohorts 1, 2, 3, and 4, vaccine virus shedding titers as measured by RT-PCR were measured on D7, and for cohorts 2 and 4, on D63. That is the case.

[0404] Safety evaluation method The shedding of attenuated RSV vaccine strains in human nasal swab samples was evaluated using an RSV quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) assay, which can specifically detect and quantify the RSV ΔNS2 / Δ1313 / I1314L(Sanofi) vaccine strain in human nasal swab samples. Based on evaluations of precision (intra-assay and intermediate precision), dilution accuracy, linearity, and specificity, the RSV ΔNS2 / Δ1313 / I1314L(Sanofi) qRT-PCR assay is suitable for clinical testing of human nasal swab samples to support the development of RSV vaccine candidates.

[0405] RSVΔNS2 / Δ1313 / I1314L (Sanofi) RT-qPCR method The RSVΔNS2 / Δ1313 / I1314L(Sanofi)RT-qPCR method was performed by the clinical trial sponsor or by a contracted testing laboratory authorized by the clinical trial sponsor.

[0406] Viral shedding was measured from nasal swab samples using the RSVΔNS2 / Δ1313 / I1314L(Sanofi)RT-qPCR assay. Development and qualification of this method are complete; it will be validated prior to Phase III clinical trials.

[0407] Explanation of the RSVΔNS2 / Δ1313 / I1314L (Sanofi) RT-qPCR method To quantify viral shedding in infants vaccinated with the RSVΔNS2 / Δ1313 / I1314L(Sanofi), we developed a qRT-PCR assay that can specifically detect and quantify RSVΔNS2 / Δ1313 / I1314L(Sanofi) in nasal swab samples.

[0408] The RSVΔNS2 / Δ1313 / I1314L(Sanofi)qRT-PCR assay was designed using the Light Cycler Probe system from Sigma. This system includes two hybridization probes designed to bind to the target 1–5 nucleotides apart. Probe 1 (donor) is labeled with a donor reporter at its 3' end. Probe 2 (acceptor) is labeled with an acceptor reporter at its 5' end. During the pre-annealing step, the PCR primers and LightCycler probes hybridize to their specific target regions, bringing the probes into proximal contact. Once this occurs, the donor dye is excited by the LightCycler, and energy is transferred from the donor to the acceptor dye. The luminescence of the acceptor reporter is detected by the Light Cycler at 640 nm.

[0409] If the probes bind but are not in close proximity, no signal is generated. The Light Cycler probe for the RSVΔNS2 / Δ1313 / I1314L(Sanofi) qRT-PCR assay targets the deletion site of the NS2 gene in RSVΔNS2 / Δ1313 / I1314L(Sanofi). Probe 1 binds before the deletion, and probe 2 binds across the deletion site. Although the primers and probes can also bind to wild-type RSV A due to their high sequence similarity, the NS2 gene is over 500 nucleotides long, so it is thought that binding will not occur if the two probes are in close enough proximity to generate a signal, making this method highly specific.

[0410] Collecting nasal swab samples from infants is a challenging task, and it is impossible to visually assess the quality of the samples. Therefore, the RNase P assay, based on the one developed by the CDC, is used in conjunction with the RSVΔNS2 / Δ1313 / I1314L(Sanofi)qRT-PCR assay to evaluate the quality of the samples.

[0411] RNase P is a human housekeeping gene. Using the RNase P assay helps to reduce the impact of false negatives caused by inadequate sample collection or handling. Amplification in the RNase P assay indicates the presence of human cells in the sample. An RNase P Cpof ≤ 37 indicates that the sample was properly collected and that sample integrity was maintained. The RNase P test should only be performed when qRT-PCR (for detecting and quantifying the RSVΔNS2 / Δ1313 / I1314L (Sanofi) vaccine strain) yields a negative result.

[0412] infectious power Infectivity evaluation items Secondary endpoints for evaluating infectivity are: • Infection with the vaccine virus in a vaccinated individual. Infection is defined as detection of the vaccine virus by RT-PCR in a nasal swab, and / or a four-fold or greater increase in the RSV A serum neutralizing antibody titer or the RSV serum anti-F IgG antibody titer.

[0413] Infectivity determination method The method for determining infectivity is described above.

[0414] immunogenicity Immunogenicity evaluation items The secondary endpoints for evaluating immunogenicity are as follows: • RSV serum neutralizing antibody titers up to D56 for cohorts 1, 2, 3, and 4 of subjects with a history of RSV infection, and up to D84 for cohorts 2 and 4. • RSV serum anti-F IgG antibody titers up to D56 for cohorts 1, 2, 3, and 4, and up to D84 for cohorts 2 and 4. • RSV A serum neutralization and serum anti-RSV F IgG antibody titers after the RSV epidemic or at least 5 months after the final dose of the vaccine.

[0415] Immunogenicity determination method The subjects with a history of RSV infection and those who have not been infected with RSV are defined above.

[0416] The immunogenicity of the vaccine candidate was evaluated, and the level of RSV F protein-binding antibody was measured (by ELISA).

[0417] RSV anti-F IgG ELISA Anti-RSV F IgG ELISA testing was performed by the clinical trial sponsor or by a contracted testing laboratory authorized by the clinical trial sponsor.

[0418] The ELISA method used is summarized below.

[0419] Description of the RSV anti-F IgG ELISA method Antibodies against the RSV F antigen were measured using anti-RSV F IgG ELISA. In short, the RSV F antigen (derived from strain RSV A2) was coated onto a microtiter plate, and the RSV F antigen was conjugated by adding a 2-fold serial dilution of a human serum sample and incubating it. Next, an HRP-conjugated anti-human IgG detection antibody was added, followed by a colorimetric substrate. The concentration of the antibody against the IgG RSV F antigen was calculated as a relative value (international units / mL) using six serial dilutions relative to a qualified internal reference material calibrated against the WHO international standard (the first international standard for antiserum against respiratory syncytial virus).

[0420] Data Management SAE Management During the study, SAE data (AEs, deaths, and those reported in the Supplemental Safety Information CRF) were integrated into the sponsor-managed GPV database after double-checking upon receipt of their respective forms. A case identification number was assigned to each case. Each case was assessed by the case management platform or its authorized representative before reporting to relevant authorities as necessary. The assessment of relevant cases was carried out in cooperation with the Global Safety Officer and the RMO. Follow-up information for the documented cases was entered into the GPV database, and a new record was created for each case.

[0421] Information from the GPV database cases was cross-referenced with information in the clinical database.

[0422] Management of clinical and laboratory data All clinical and laboratory data, as defined by the data reported to the Clinical Research Board (CRB), were handled by the sponsor's Clinical Data Management (CDM) platform or an authorized representative.

[0423] During the study, clinical data reported to the CRB were integrated into the clinical database under the responsibility of the sponsor's CDM platform. Systematic quality control, including on-site data monitoring and computerized logical and / or consistency checks, was applied to detect errors or omissions. In addition, sponsor staff conducted several data reviews throughout the study. Any questions regarding the reported clinical data were submitted to the principal investigator using the EDC system for resolution. This process ensured database integrity by implementing and monitoring individual passwords at each stage, maintaining appropriate database access.

[0424] Immunogenicity data verification was performed at the laboratory level, following the procedures of each laboratory. Information from the laboratories was checked for consistency before integration into the clinical data warehouse.

[0425] After integrating all corrections across the entire dataset and completing the reconciliation of SAE information available from the CDM and GPV departments, the database was made public for statistical analysis.

[0426] Data Review Prior to locking the database, a blind review of the data was conducted through a data management-led data review process.

[0427] Determination of statistical methods and sample size Statistical methods for the primary objective The statistical methodology was based on the use of two-sided 95% confidence intervals (CIs).

[0428] The 95% confidence interval (CI) of the point estimates was calculated using the exact binomial distribution (Clopper-Pearson method) for the proportions.

[0429] For immunogenicity data, use the logarithm of titer / titer ratio. 10 Assuming the transformation follows a normal distribution, we first use the usual normal distribution calculation to log 10 The mean and 95% confidence interval (CI) were calculated for (potency / potency ratio). Next, an inverse logarithmic transformation was applied to the calculation results to obtain the geometric mean potency (GMT), geometric mean potency ratio (GMTR), and their 95% CIs.

[0430] safety Adverse reactions (ARs) reported involuntary based on requests, AEs (including SAEs), MAAEs, and AESIs reported spontaneously were summarized. Key parameters are listed with their 95% confidence intervals. At least the following parameters were presented for all subjects, regardless of baseline serological status, after each vaccination, and by vaccine group: • Systemic adverse events (AEs) occurring within 30 minutes of administration, as reported spontaneously (immediate AEs as reported spontaneously) • Incidence, time to onset, intensity, number of days since onset, treatment performed, and whether the reaction led to early termination of this study were recorded for each dose, including involuntary, requested administration site reactions and involuntary, requested systemic reactions, all within 28 days after each dose. When two or more intensity levels were reported, the highest intensity was used. • Organ-specific major classification (SOC) and basic term (PT), relationship, intensity, time to onset, duration, and whether the AE led to early termination of this study, all spontaneously reported AEs occurred within 28 days after each administration. • SOC and PT, severity criteria, time to onset, outcomes, relationships, and all SAEs that occurred throughout the study, other than whether SAEs led to early termination throughout the study. • For SOC and PT, and related vaccinations, all MAAEs and AESIs reported within 28 days of each vaccination

[0431] Using a Bayesian method based on the posterior distribution, the differences between each RSV formulation and placebo for the following safety endpoints were determined: • Any grade 3 lower respiratory tract disease, e.g., wheezing, pneumonia, persistent tachypnea, laryngotracheobronchitis • Grade 3 overheating

[0432] immunogenicity For each vaccine group in RSV-uninfected subjects, point estimates and their 95% confidence intervals (CIs) for the following parameters are presented for RSV A neutralizing antibody titers up to D56 for cohorts 1, 2, 3, and 4, and up to D84 for cohorts 2 and 4: ·GMT • GMTR based on baseline antibody titer • Antibody response rate is defined as the percentage of subjects whose RSV A serum neutralizing antibody titer increased by four times or more compared to the baseline value. • Presented the inverse cumulative distribution curve (RCDC). Pairwise comparisons between vaccine groups may be performed as exploratory analyses to compare antibody response rates or GMT for descriptive purposes.

[0433] The 95% confidence interval (CI) for the difference in proportions between the two groups was calculated using Wilson's score method without continuity correction. The CI for the ratio of GMTs between the two groups was calculated using the logarithmic scale between the two groups with normal approximation. 10 It was calculated from the difference in the average values ​​of the converted titers.

[0434] Statistical methods for secondary purposes statistical methods safety For each vaccine group, point estimates and their 95% confidence intervals (CIs) for the following parameters are presented according to baseline serological status 7 days after each vaccination (D7 for cohorts 1, 2, 3, and 4, and D63 for cohorts 2 and 4): • GMT of vaccine virus shedding measured by RT-PCR

[0435] infectious power For each vaccine group, point estimates and their 95% confidence intervals (CIs) for the following parameters are presented according to baseline serological status: Cohorts 1, 2, 3, and 4 after vaccination 1 (D56), and Cohorts 2 and 4 after vaccination 2 (D84): • The proportion of vaccinated individuals infected with the vaccine virus. Infection is defined as detection of the vaccine in a nasal swab by polymerase chain reaction (PCR), and / or a four-fold or greater increase in the RSV A serum neutralizing antibody titer or the RSV serum anti-F IgG antibody titer.

[0436] immunogenicity For the following evaluation items, point estimates of GMT and GMTR, along with their 95% confidence intervals (CIs), are presented for each vaccine group: • For subjects with a history of RSV infection, RSV A serum neutralizing antibody titers up to D56 for cohorts 1, 2, 3, and 4, and up to D84 for cohorts 2 and 4. • RSV serum anti-F IgG antibody titers up to D56 for cohorts 1, 2, 3, and 4, and up to D84 for cohorts 2 and 4, categorized by baseline serological status. • RSV A serum neutralization and anti-RSV F IgG antibody titers, categorized by baseline serological status, after the RSV epidemic or at least 5 months after the final vaccination dose.

[0437] Where applicable, the antibody response was also presented.

[0438] Target population for analysis The largest group of people analyzed The largest analysis population (FAS) is defined as a subgroup of randomized subjects who received at least one dose of the study vaccine. Data from any subject infected with wt RSV confirmed by testing will be excluded from immunogenicity and viral shedding analyses from the date of wt RSV infection onward.

[0439] Safety analysis target population The Safety Analysis Population (SafAS) was defined as subjects who had received at least one dose of the study vaccine. All subjects underwent safety analyses according to the vaccine actually received after each dose, and according to the vaccine received at the time of the first dose after any subsequent vaccination.

[0440] Safety data recorded for vaccines administered outside of the protocol design were excluded from the analysis (and listed separately).

[0441] Target population for protocol fit analysis The protocol-fitted analysis population (PPAS) is a subpopulation of the FAS. Two specific PPAS populations were defined: PPAS1 after one dose (for subjects in cohorts 1, 2, 3, and 4) and PPAS2 after two doses (for subjects in cohorts 2 and 4).

[0442] Subjects exhibiting at least one of the following relevant protocol deviations were excluded from PPAS: • Baseline serum sample was not collected at the time of hospital visit (01 / D0). • A subject with a temporary contraindication did not receive vaccine 1 within an appropriate time window from randomization. • The subject did not meet all of the inclusion criteria specified in the protocol, or met at least one of the exclusion criteria specified in the protocol. • The subject did not receive the vaccine / did not complete the vaccination schedule. • The subjects received a vaccine other than the one they were randomly assigned to. • The vaccine preparation and / or administration were not carried out in accordance with the protocol. • Subjects who received a therapy prohibited by the protocol prior to the post-vaccination serum sample; Subjects with a confirmed diagnosis of wild-type (wt) RSV prior to the post-vaccination serum sample. • Subjects whose blinding was performed urgently by the principal investigator.

[0443] Only PPAS1 was excluded from the list of subjects exhibiting at least one of the following relevant protocol deviations: • Serum sample taken after vaccination was not collected at 03:00 upon arrival at the hospital. • Serum samples taken after vaccination were not collected within the appropriate time window at the time of hospital visit (03).

[0444] Subjects exhibiting at least one of the following relevant protocol deviations were excluded from PPAS2 (for subjects in cohorts 2 and 4): • The subject did not receive vaccine 2 within the appropriate time window at the time of arrival at the hospital (03). • Serum samples were not collected at 05:00 AM after vaccination. • Serum samples taken two days after vaccination were not collected within the appropriate time window at 05:00 upon arrival at the hospital.

[0445] In addition to the reasons listed above, subjects were also excluded from PPAS if their baseline serum sample or post-vaccination serum sample did not yield valid test results (i.e., the RSV A serum neutralizing antibody titer result was missing).

[0446] Note: For PPAS1 (after one dose), the time points to consider are D0 (visit 01) for vaccination and D56 (visit 03) for post-vaccination serum sample. For PPAS2 (after two doses), the time points to consider are both D0 (visit 01) and D56 (visit 03) for vaccination, and D84 (visit 05) for post-vaccination serum sample.

[0447] One or more other populations to be analyzed Randomized subjects A randomized population is a group of people to whom the vaccine group has been assigned.

[0448] The population used for analysis Safety analyses were performed using SafAS. The subjects were analyzed according to the vaccine actually received after each vaccination, and according to the vaccine received as the first dose after any optional vaccination.

[0449] Immunogenicity analysis was performed on the largest analysis population, and key immunogenicity parameters were analyzed on the protocol-fitted analysis population. In FAS, subjects were analyzed according to the vaccine group to which they were randomized. In PPAS, subjects were analyzed according to the vaccine they actually received.

[0450] Handling of missing data and outliers safety No data was supplemented. Nevertheless, at the time of statistical analysis, missing data relationships were assumed to exist. No outlier search was performed. In all target lists, partial and missing data were clearly indicated as missing.

[0451] immunogenicity Missing data was not imputed. No outlier checks or searches were performed.

[0452] For the calculation of GMT and ratios for subjects with nAb titers exceeding the threshold, pre-vaccination or post-vaccination values ​​reported as below the lower limit of quantification (LLOQ) were converted to half the LLOQ value.

[0453] For GMTR calculations, pre-vaccination values ​​reported as less than LLOQ were converted to LLOQ, and post-vaccination values ​​reported as less than LLOQ were converted to half of LLOQ if only the numerator or denominator was less than LLOQ. If both the numerator and denominator were less than LLOQ, both were converted in the same way so that the individual titer ratios equaled 1.

[0454] All values ​​reported to exceed the upper limit of quantitative analysis (ULOQ) were converted to ULOQ.

[0455] Effectiveness Missing data was not imputed. No outlier checks or searches were performed.

[0456] Intermediate / Preliminary Analysis This analysis was performed using a stepwise method.

[0457] Several blinded early safety data reviews were conducted on safety data collected from subjects in each cohort at specific point in time.

[0458] The following describes an open-label interim analysis of subjects from Cohorts 1, 2, and 3, and at least 90 subjects enrolled in Cohort 4. This interim analysis includes subjects who have provided safety data up to D84 and for whom D84 immunogenicity results are available. Special processes were implemented to maintain blinding at the subject and investigator levels.

[0459] An open-label early analysis will be planned for participants from all cohorts (Cohorts 1, 2, 3, and 4). This early analysis will be conducted when all participants have provided safety data up to D84 and the D84 immunogenicity results are available. This early analysis will require deblinding of data; a special process will be implemented to maintain blinding at the participant and investigator levels. Based on the results of this analysis, dosages for future studies will be determined.

[0460] The final open-label statistical analysis will address the objectives for all subjects (cohorts 1, 2, 3, and 4), including post-epidemic data.

[0461] Since the hypothesis is not being tested, statistical adjustment is unnecessary.

[0462] Determination of sample size and calculation of power Since this study does not involve any statistical hypotheses, sample size calculations were not performed.

[0463] We planned to sequentially enroll a total of 300 subjects into one of four cohorts: • Cohort 1 (single dose): 40 subjects, i.e., 20 subjects per vaccine group (low-dose RSV or placebo) • Cohort 2 (two doses): 40 subjects, i.e., 20 subjects per vaccine group (low-dose RSV or placebo) • Cohort 3 (single dose): 40 subjects, i.e., 20 subjects per vaccine group (high dose of RSV or placebo) • Cohort 4 (two doses): 180 subjects, i.e., 60 subjects per vaccine group (high dose of RSV, low dose of RSV, or placebo). The actual number of subjects to be registered in each cohort will be discussed in the following interim results.

[0464] This study does not include statistically powerful hypotheses or sample size calculations, but a sample size of 100 subjects in the low-dose RSV group (20 from cohort 1, 20 from cohort 2, and 60 from cohort 4) provides a 95% probability of observing an event with a true incidence of 3%. A sample size of 80 subjects in the high-dose RSV group (20 from cohort 3 and 60 from cohort 4) provides a 95% probability of observing an event with a true incidence of 3.75%.

[0465] This study planned to enroll a total of 300 subjects. This would include 120 subjects in the placebo group, 100 subjects in the low-dose RSV group, and 80 subjects in the high-dose RSV group. Table 10 below presents the number of subjects by serological status, total, and RSV group, based on the fact that the proportion of people with a history of RSV infection varied from 5% to 35% (derived from LID / NIH screening data), and provides a comprehensive overview of the ratio of RSV-uninfected subjects to subjects with a history of RSV infection enrolled in this study.

[0466] [Table 26]

[0467] Example 2: Interim results of the VAD00001 study In the VAD00001 study, approximately 155 participants (infants and toddlers) received the investigational drug at any dose or administration regimen; however, complete deblinding was not performed, so the final number of participants who received the investigational drug is unknown. The VAD00001 interim results showed that the vaccine candidate was well-tolerated and demonstrated high infectivity, genetic stability, and a robust immune response.

[0468] An ongoing Phase I / II trial (VAD00001) is being conducted in the United States and South America (Chile and Honduras). This trial is testing two dose levels (5.6 log) of the RSVΔNS2 / Δ1313 / I1314L (Sanofi) vaccine. 10 PFU and 6.2log 10 The safety, immunogenicity, and infectivity of PFUs are being assessed in a continuous cohort study, and this assessment will continue.

[0469] This study was conducted to ensure a safe, stepwise approach to reaching the dose in Cohort 4. Cohort 4 had doses of 5.6 and 6.2 log per dose. 10 By designing for both PFU, 1) as suggested by data from the NIH trial, 6.2 log per dose in Phase III. 10 PFU (5.6 log per dose) 10 1) To confirm its applicability as an alternative to PFU, and 2) to clinically justify future dose range boundaries of the non-freezing liquid formulation toward final commercialization by exploring the safety, infectivity, and immunogenicity outcomes of two doses under trial.

[0470] Study participants aged 6-18 months were assigned to the following interventions, and this assignment will continue: Cohort 1 (planned sample size 40, registered sample size 36): 5.6 log for single dose. 10 PFU RSVΔNS2 / Δ1313 / I1314L (Sanofi) or placebo Cohort 2 (40 planned participants, 21 enrolled): 5.6 log of 2 doses10 PFU RSVΔNS2 / Δ1313 / I1314L (Sanofi) or placebo, every 2 months Cohort 3 (planned sample size 40, registered sample size 22): 6.2 log for a single dose. 10 PFU RSVΔNS2 / Δ1313 / I1314L (Sanofi) or placebo Cohort 4 (180 planned participants, 180 enrolled participants): 5.6 log for two doses. 10 PFU RSVΔNS2 / Δ1313 / I1314L (Sanofi), 6.2log 10 PFU RSVΔNS2 / Δ1313 / I1314L (Sanofi) or placebo, every 2 months Baseline RSV serological status: R+ / R- (See below for the definition used in this study).

[0471] Blood samples from cohorts 1 and 3 were collected before and 56 days after administration of the study vaccine. Blood samples from cohorts 2 and 4 were collected before each administration and 28 days after the second dose. All participants in cohorts 1, 2, 3, and 4 were required to provide blood samples within one month following the end of the RSV epidemic, or at least five months after the final vaccine administration, to measure post-epidemic RSV antibody titers, determine whether a quadrupling or greater increase in RSV antibody titers occurred during the RSV epidemic, indicating infection with wild-type RSV undetected by surveillance, and explore residual antibody titers for one post-epidemic period.

[0472] For all participants, nasal swab samples were collected 7 days after the first vaccine dose for cohorts 1, 2, 3, and 4; and 7 days after the second vaccine dose for cohorts 2 and 4; and collection will continue. Samples are tested for vaccine shedding in cases of respiratory pathogen illness; and testing will continue. All study participants provided nasal swabs when illness was reported and 48 hours later; and this provision will continue.

[0473] Safety follow-up included emergency surveillance 30 minutes after vaccination, involuntary reporting of adverse reactions based on requests, collection of spontaneously reported AEs, MAAEs, and AESIs for 28 days after each vaccination, and SAEs throughout the entire study (up to 12 months).

[0474] As planned in the protocol, an open-label interim analysis for dose selection of the RSVΔNS2 / Δ1313 / I1314L (Sanofi) vaccine was conducted for participants from cohorts 1, 2, and 3 and the first 91 participants enrolled in cohort 4. This interim analysis was conducted after participants had provided safety data up to 28 days after the second vaccine dose and immunogenicity results were available at that time, and will continue. Dose selection for future development (i.e., 6.2 log 10 PFU (Intermediate Target Value for Future Effectiveness) was based on a descriptive comparison of the safety, infectivity, and immunogenicity of either dose in all participants up to 28 days after the second vaccine dose. It was determined whether the two doses in the trial should be included in the future effective range. The results of the interim analysis are summarized below.

[0475] Infants with detectable serum IgA against RSV F at baseline were considered to have a history of RSV infection, while infants without detectable serum IgA against RSV F at baseline were considered RSV-uninfected. This method allows for a more discriminative assay, enabling the differentiation of participants with a history of RSV infection from RSV-uninfected participants who possess transplacentally transferred serum antibodies. The rationale for clearly defining uninfected and RSV-infected participants in a Phase I / II trial is to thoroughly assess the safety of the attenuated live vaccine (LAV) in the uninfected population, given that past RSV infection may influence the infectivity of subsequent RSV infections, including LAV. Assuming the IgA test is a more discriminative assay, the results based on the determination of participants' baseline serological status using this serum IgA assay for RSV F are as follows: R-; RSV-uninfected: Participants with titer < limit of detection [LOD] Participants with R+; a history of RSV infection: titer ≥ LOD Other details undecided

[0476] The interim results presented below include 167 participants assessed for safety (50.3% female, mean age 11.0 ± 3.86 months, 5.4% Black / African American, 38.3% Hispanic / Latino), and 139 participants assessed for infectivity and immunogenicity, for whom IgA serological status data was available. Three participants out of the 170 recruited at the time of this interim analysis were not included because they had not received the study intervention. Participants with a history of RSV respiratory illness prior to the evaluation time were excluded from the immunogenicity analysis at the corresponding time point.

[0477] Conclusions regarding safety, immunogenicity, and infectivity safety The safety profile of each dose of RSVΔNS2 / Δ1313 / I1314L (Sanofi) vaccine was assessed in all infants and toddlers, regardless of baseline serological status, after each administration. Post-vaccination symptoms were comparable between groups and across cohorts. In this medium-sized participant group at the time of the interim analysis, a higher proportion of participants in the high-dose group were observed for involuntary, requested-based administration site reactions after vaccination, while AESIs (Antimicrobial Stem Infections) after any vaccination tended to be more frequent in the low-dose group.

[0478] During the study, two unrelated SAEs were reported outside the acute phase: one grade 3 (left hand cellulite) in the low-dose group and one grade 2 (RSV-MAARI) in the placebo group. Two AESIs each in the low-dose group (nasopharyngitis), high-dose group (croup and strider in the same participant), and placebo group (nasopharyngitis and cough) after vaccination were classified as related by the principal investigator. All VAD00001 study participants were followed up during one RSV epidemic period prior to the start of the Phase III program, and this will continue. Swab data collected at illness visits are still expected and will be provided in later analyses. Given the effect of the Covid-19 pandemic on the RSV cycle during study participation in Cohorts 1, 2, and 3, laboratory-confirmed illnesses in these cohorts are likely to be lower than in Cohort 4. The inventors do not anticipate disease exacerbation by this candidate due to its attenuated nature and the data available to date. However, the inventors will note any available data regarding RSV disease after vaccination as it becomes available.

[0479] The overall safety profile was similar between RSV-uninfected participants and those with a history of infection.

[0480] As of November 30, 2022, there have been no reports of deaths during the study.

[0481] Overall, the safety data indicate an acceptable safety profile for this candidate at both dose levels (see Tables 11 and 12: Summary of post-vaccination safety – Safety analysis population).

[0482] immunogenicity Approximately 70 percent (70%) of vaccinated individuals achieved a fourfold increase in neutralizing antibody titer after the second dose in both the low-dose and high-dose groups, compared to 61% and 47% after the first dose in RSV-uninfected participants in the low-dose and high-dose groups, respectively. This increase in the proportion of participants achieving a fourfold response after the second dose supports the use of a second dose in this population. The fact that 70% achieved this quadruple increase after the second dose is consistent with the expected clinical efficacy target of 70% for this candidate. After one or two doses of vaccination, 75% achieved a fourfold increase in serum neutralizing antibody titer. The proportion of RSV-infected participants who similarly achieved a fourfold response after vaccination (36% and 22% in the low-dose and high-dose groups, respectively) suggests that this subgroup may also benefit. It should be noted that this is from a moderately sized participant sample at this point in the interim analysis (n=20 out of 97 vaccinated individuals).

[0483] In summary, these data strongly support the use of the RSVΔNS2 / Δ1313 / I1314L(Sanofi) vaccine within the study-effective range for this candidate, including doses of 5.6 and 6.2 log PFU / dose. (See Tables 13 and 14).

[0484] Vaccine virus shedding and infectivity After each vaccine administration, vaccine infectivity was assessed by considering the increase in neutralizing antibody titers or serum IgG multipliers, as well as the shedding of vaccine virus. High vaccine infectivity (over 80% and 70% after the first and second doses, respectively, in RSV-uninfected individuals) supports the idea that this is a promising vaccine candidate associated with good vaccine infectivity. When considering infectivity after any vaccine administration, over 90% of participants had evidence of infection. Relatively high infectivity was observed in a small cohort of participants with a history of RSV infection (80% and 33.3% after the first dose and 60% and 50% after the second dose in low-dose and high-dose recipients), suggesting potential in this group. In addition, in RSV-uninfected participants, the proportion of vaccine-induced viral shedding decreased significantly after the second vaccination compared to the first vaccination (over 70%) (roughly 20%), as previously demonstrated with other effective attenuated live mucosal virus vaccines. Here, the subsequent "challenge" in the form of the second vaccine dose is characterized by a significant decrease in vaccine-induced viral shedding. Notably, the available shedding data for this cohort consisted of data from a single time point after each vaccination (7 days after vaccination). This coincides with the peak time of viral shedding demonstrated in other RSV attenuated live virus (LAV) vaccine trials, although some shedding individuals may have been missed. Due to this limitation of available shedding data, the results obtained are particularly promising. (See Tables 15 and 16).

[0485] Overall conclusion The interim analysis results showed promising safety, immunogenicity, and infectivity profiles for the RSVΔNS2 / Δ1313 / I1314L(Sanofi) candidate.

[0486] No safety concerns were identified after one or two doses of the clinical trial-grade RSVΔNS2 / Δ1313 / I1314L(Sanofi) vaccine at any dose level, or based on baseline serological status.

[0487] Conclusions regarding immunogenicity based on vaccine viral shedding and baseline IgA serological status indicate that significant vaccine administration was demonstrated at both dose levels, with 70% of RSV-uninfected participants achieving a four-fold serum neutralizing antibody response after a second dose at both dose levels.

[0488] These results are 5.6log 10 PFU / dose and 6.2log 10 This confirms the efficacy range of this candidate, including the PFU / dose ratio, and supports its future development. An early analysis will be conducted after all participants have completed the 28-day post-vaccination milestone, once all results have been deblinded.

[0489] [Table 27]

[0490] [Table 28]

[0491] [Table 29]

[0492] [Table 30]

[0493] [Table 31]

[0494] [Table 32]

[0495] [Table 33]

[0496] Table 34

[0497] Table 35

[0498] Table 36

[0499] Table 37

[0500] Table 38

[0501] Table 39

[0502] Table 40

[0503] Table 41

[0504] Table 42

[0505] Table 43

[0506] Table 44

[0507] Table 45

[0508] Table 46

[0509] Table 47

[0510] Table 48

[0511] Table 49

[0512] Table 50

[0513] Table 51

[0514] Table 52

[0515] Table 53

[0516] Table 54

[0517] Table 55

[0518] Table 56

[0519] Table 57

[0520] Table 58

[0521] Table 59

[0522] Table 60

[0523] Table 61

[0524] Table 62

[0525] Table 63

[0526] Table 64

[0527] [Table 65]

[0528] [Table 66]

[0529] [Table 67]

[0530] [Table 68]

[0531] Example 3: Study on the immunogenicity and safety of three different dose concentrations of respiratory syncytial virus vaccine in infants and toddlers. Protocol name: A parallel-group, phase III, randomized, observer-blinded, placebo-controlled, multicenter, multinational, multigroup study to demonstrate the non-inferiority of low-dose immune response compared to standard dose and to evaluate the safety of respiratory syncytial virus vaccine in infants and toddlers.

[0532] Theoretical basis: To complement the stability studies of the RSVΔNS2 / Δ1313 / I1314L (Sanofi) vaccine in the context of vaccine effectiveness, this study will investigate immunogenicity and safety at three vaccine dose concentrations (i.e., low dose [LD: target 5.4 log10 PFU / dose], standard dose [SD: target 6.4 log10 PFU / dose], and high dose [HD: target 7.0 log10 PFU / dose]). Therefore, the objective of this study is to evaluate whether LD is non-inferior to SD when determined by RSV A and RSV B serum neutralizing antibodies 28 days (day 85) after the second vaccination. The goal is to demonstrate that LD will produce a non-inferior immune response to SD. In addition, this study aims to investigate the safety of the vaccine in infants and toddlers born at full term (i.e., 37 weeks or more of gestation) and prematurely (i.e., 28-36 weeks of gestation).

[0533] [Table 69]

[0534] [Table 70]

[0535] [Table 71]

[0536] [Table 72]

[0537] [Table 73]

[0538] [Table 74]

[0539] Inclusion Criteria / Exclusion Criteria Inclusion Criteria Participants are eligible to participate in this study only if they meet all of the following criteria:

[0540] age Age at enrollment: between 6 months and under 22 months old 1 1 "6 months to under 22 months old" means from the 6-month birthday to the day before the 22-month birthday. The second dose of the vaccine must be administered before the research participant reaches 24 months of age.

[0541] Participant types and disease characteristics Participants who are deemed healthy based on a medical evaluation including their medical history.

[0542] For Cohort 1 and Cohort 2 (provided that the safety profile of the RSVΔNS2 / Δ1313 / I1314L (Sanofi) vaccine in Cohort 1 is satisfactory): Participants born between 28 and 36 weeks of gestation who are medically stable as determined by the principal investigator based on the following definition: "Medically stable" means a premature infant who does not require significant medical support or ongoing management for a debilitating disease and who has demonstrated a sustained recovery clinical course by the time of receiving the first dose of the research intervention.

[0543] Regarding Cohort 2: Participants born at full term (37 weeks or more of pregnancy)

[0544] Informed consent I01. The informed consent form is signed and dated by one or more parents or other LARs (and by an independent witness as required by local regulations).

[0545] Other components Participants and one or more parents / LARs are able to accompany them to all scheduled visits and follow all research procedures.

[0546] Exclusion criteria Participants are ineligible for this study if they meet any of the following criteria:

[0547] medical condition E01. Known or suspected congenital or acquired immunodeficiency; or received immunosuppressive therapy such as anticancer chemotherapy or radiotherapy within the past 6 months; or long-term systemic corticosteroid therapy (prednisone or equivalent for more than 2 consecutive weeks within the past 3 months) E02. Known systemic hypersensitivity to any of the research intervention drug components, or a history of life-threatening reactions to the research intervention drug used in the study or any formulation containing the same substance. 2 2 The ingredients of the research intervention drug will be listed elsewhere. E03. Chronic diseases that, according to the principal investigator, may hinder the conduct or completion of the study. 3 3 Chronic diseases include, but are not limited to, heart disorders, lung diseases (including a history of any reactive airway disease or treatment with bronchodilators or inhaled corticosteroids), atopic dermatitis, renal disorders, autoimmune disorders, diabetes, psychomotor disorders, and known congenital or hereditary disorders. E04. Medical history of diagnosed wheezing 4 . 4 Children with a history of recurrent wheezing will be excluded. Children with a single episode of wheezing in the past may be included if the episode did not involve hospitalization or if there is no family history of wheezing. E05. Any acute febrile illness within the past 48 hours that is severe enough to interfere with successful vaccination on the day of vaccination, as determined by the principal investigator. Prospective participants should not be enrolled in this study until their condition has resolved or the febrile event has subsided. E06. Cases of probable or confirmed ongoing viral respiratory infections (including COVID-19, influenza, rhinovirus, etc.) at the time of registration. Prospective participants should not be enrolled in this study until their respiratory infection has resolved. E07. Not limited to, • People infected with human immunodeficiency virus (HIV) • Individuals who have received chemotherapy within 12 months prior to study registration. • Individuals who have received immunosuppressant therapy (within the past 6 months) or who are currently receiving it (at the time of registration) • Those who have survived organ or bone marrow transplants. This includes members of households with immunocompromised individuals. At the discretion of the principal investigator, there may have been close contact with other immunocompromised individuals within 30 days of each vaccination.

[0548] Past treatment history / combination therapy E08. The participant's mother has previously received or is scheduled to receive the clinical trial RSV vaccine during pregnancy and / or breastfeeding. E09. You have received or are scheduled to receive one of the following vaccines before registration or after initial research intervention: • Any other intranasal attenuated live vaccine administered before or within 28 days after the initial study intervention. • Any other injectable live attenuated vaccine within 28 days before or after the initial study intervention drug administration, except when administered on the day of the initial study intervention drug administration. Concomitant administration on the day of the initial study intervention drug administration is permitted. E10. Previously received a clinical trial RSV vaccine, or currently receiving any anti-RSV agent (such as ribavirin or RSV immunoglobulin) at the time of registration. Previously received nircevimab within 6 months or palivizumab within 3 months prior to the initial study vaccine dose. E11. The patient has received immunoglobulin, blood, or blood-derived products in the past three months. E12. The patient received intranasal or intraocular medication within 3 days prior to study registration.

[0549] Past / contemporary clinical trial experience E13. At the time of enrollment in this study, or scheduled to participate in another clinical trial investigating a vaccine, drug, medical device, or medical procedure.

[0550] Other exclusions E14. Deprived of freedom under emergency treatment, or involuntarily hospitalized. E15. Identified as the biological or adopted child of the principal investigator or an employee directly involved in the proposed research.

[0551] overview: This study will be a phase III, parallel-group, randomized, observer-blinded, placebo-controlled, multinational, multicenter, multigroup study conducted on 947 healthy children enrolled at 6 months of age. The objectives of this study are to evaluate the non-inferiority of the immune response of LD compared to SD RSVΔNS2 / Δ1313 / I1314L (Sanofi) vaccine, and to assess the safety of SD and HD vaccines in preterm children and HD vaccine in full-term children administered via the intranasal route, compared to placebo.

[0552] The research details include: The study period for each participant will be approximately 8-9 months, including a safety follow-up telephone interview 6 months after the second administration of the intervention drug.

[0553] The study intervention drug will be administered to participants on days D01 and D57 (one intranasal dose per nostril at each time point).

[0554] The frequency of hospital visits is shown in Table 1. Safety data will be collected at all study visits and at designated times after contact is made with the study participant's parent / legal decision-maker (LAR).

[0555] Number of participants: A total of 947 participants are expected to be randomized: 35 in Cohort 1 and 912 in Cohort 2.

[0556] Research arm and period: In each study group (RSVΔNS2 / Δ1313 / I1314L(Sanofi) vaccine group and placebo group), eligible participants will be randomized to receive either one dose of the RSVΔNS2 / Δ1313 / I1314L(Sanofi) vaccine or two intranasal doses of placebo (56-day intervals, i.e., D01 and D57).

[0557] The research arm will be as follows: Enrollment of Cohort 1 participants (born prematurely) will be carried out using a sequential / staged approach. Step 1: The first 20 participants will be randomized in a 1:1 ratio to receive either SD RSVΔNS2 / Δ1313 / I1314L (Sanofi) or placebo. Step 2: Based on the criterion of acceptable safety profile (up to 28 days after the first vaccination), an additional 15 participants will be randomized in a 2:1 ratio to receive either HD RSVΔNS2 / Δ1313 / I1314L (Sanofi) or placebo. Step 1: Group 1 (N=10): Two doses of SD RSVΔNS2 / Δ1313 / I1314L (Sanofi) (Target 6.4 log10 PFU / dose) Group 2 (N=10): Two doses of placebo The safety of SD RSVΔNS2 / Δ1313 / I1314L (Sanofi) is required: Step 2: Group 3 (N=10): Two doses of HD RSVΔNS2 / Δ1313 / I1314L (Sanofi) (Target 7.0 log10 PFU / dose) Group 4 (N=5): Two doses of placebo Subject to an acceptable safety profile for hemodialysis in Cohort 1, participants born prematurely will be opened to enrollment in Cohort 2. Participants in Cohort 2 will be randomized into groups 1-4 in a ratio of 2:2:1:1, respectively. Group 1 (N=304): Two doses of LD RSVΔNS2 / Δ1313 / I1314L (Sanofi) (Target 5.4 log10 PFU / dose) Group 2 (N=304): Two doses of SD RSVΔNS2 / Δ1313 / I1314L (Sanofi) (target 6.4 log10 PFU / dose) Group 3 (N=152): Two doses of HD RSVΔNS2 / Δ1313 / I1314L (Sanofi) (Target 7.0 log10 PFU / dose) Group 4 (N=152): Two doses of placebo. Cohorts 1 and 2 will be registered concurrently. At each vaccination visit, 0.1 mL of either the RSVΔNS2 / Δ1313 / I1314L (Sanofi) vaccine or a placebo will be administered into each nostril using a clinical trial device. The research period will be approximately 8 to 9 months for each participant.

[0558] One or more research intervention drugs: Clinical trial drug 1: LD RSVΔNS2 / Δ1313 / I1314L (Sanofi) vaccine (Target 5.4 [5.6 ± 0.3] log10 PFU / 0.2 mL) • Form: Liquid for intranasal spray • Composition: Each 0.2 mL dose of the RSVΔNS2 / Δ1313 / I1314L (Sanofi) vaccine will contain attenuated live RSV with i) a 523 nucleotide deletion in the NS2 gene, ii) an amino acid deletion in the L protein (Δ1313; deletion of S1313), and iii) a genetically stabilizing mutation in the L gene (I1314L). Approximately 0.1 mL will be delivered to each nostril as a droplet mist using an intranasal atomizer device. • Route of administration: Intranasal cavity Clinical trial drug 2: SD RSVΔNS2 / Δ1313 / I1314L (Sanofi) vaccine (target 6.4 log10 PFU / 0.2 mL) • Same form, composition, and route of administration as Formulation 1. Clinical trial drug 3: HD RSVΔNS2 / Δ1313 / I1314L (Sanofi) vaccine (Target 7.0 [6.9 ± 0.3] log10 PFU / 0.2 mL) • Same form, composition, and route of administration as Formulation 1. Clinical trial drug 4: Placebo • Form: Liquid for intranasal spray • Composition: Buffer solution, the same histidine-based formulation buffer used in the RSVΔNS2 / Δ1313 / I1314L (Sanofi) vaccine, delivered as approximately 0.1 mL per nostril. • Route of administration: Intranasal cavity

[0559] Statistical considerations: Statistical Hypothesis Primary immunogenic purpose Twenty-eight days after the second dose of the RSVΔNS2 / Δ1313 / I1314L(Sanofi) vaccine was administered to participants in Cohort 2, the geometric mean titers (GMT) of neutralizing RSV(A and B) antibodies in the LD RSVΔNS2 / Δ1313 / I1314L(Sanofi) group will be compared to those in the SD RSVΔNS2 / Δ1313 / I1314L(Sanofi) group. For each RSV antibody, the following hypotheses will be tested: H0:GMT(rsv,LD) / GMT(rsv,SD)≦2 / 3 H1:GMT(rsv,LD) / GMT(rsv,SD)>2 / 3 In the formula, GMT(rsv,LD) and GMT(rsv,SD) are the GMTs of RSV antibodies (A and B) in LD RSVΔNS2 / Δ1313 / I1314L(Sanofi) and SD RSVΔNS2 / Δ1313 / I1314L(Sanofi) from Cohort 2, respectively.

[0560] If the lower limit of the two-sided 95% CI of the GMT ratio between the LD RSVΔNS2 / Δ1313 / I1314L(Sanofi) group and the SD RSVΔNS2 / Δ1313 / I1314L(Sanofi) group is >2 / 3 for both neutralizing RSV antibodies (A and B), the null hypothesis of recessiveness is rejected, and the non-inferiority (NI) of LD RSVΔNS2 / Δ1313 / I1314L(Sanofi) compared to SD RSVΔNS2 / Δ1313 / I1314L(Sanofi) is demonstrated.

[0561] statistical analysis All endpoints will be summarized at each time point for each intervention group. For the analysis of Cohort 1, groups 2 and 4 (i.e., the placebo group) may be pooled. The results will be presented separately for each cohort.

[0562] Generally, categorical variables are summarized and presented using frequency counts, proportions, and confidence intervals (CIs). The 95% CI of point estimates is calculated using a normal approximation of quantitative data and an exact binomial distribution (Clopper-Pearson method) for proportions. For GMT and GMTR, the 95% CI of point estimates is calculated using a normal approximation, assuming they follow a log10 normal distribution.

[0563] Immunogenicity analysis will be performed on the protocol-fitted analysis population (PPAS). If the difference between the number of participants in the PPAS and the number of participants in the FAS is 10% or more, the analysis may be performed on the largest analysis population (FAS).

[0564] Safety analysis will be conducted on the Safety Analysis Set (SafAS).

[0565] Key evaluation criteria Immunogenicity analysis The two-sided 95% confidence interval (CI) of the GMT ratio between the LD RSVΔNS2 / Δ1313 / I1314L(Sanofi) group and the SD RSVΔNS2 / Δ1313 / I1314L(Sanofi) group from Cohort 2 will be calculated assuming that the log10 transformation of titers follows a normal distribution. The null hypothesis of recessiveness will be rejected if the lower limit of the two-sided 95% CI for both RSV A and RSV B antibodies is greater than two-thirds.

[0566] Safety analysis Safety parameters, including the frequency of immediate responses, involuntary responses based on requests, and spontaneously reported AEs, MAAEs, AESIs, and SAEs, will be described for each study intervention group after each administration, and the 95% confidence interval (CI) of the point estimates will be calculated using the exact binomial distribution (Clopper-Pearson method) for proportions.

[0567] Interim analysis An open-label primary completion analysis will be conducted using data collected for immunogenicity and safety for each cohort up to 28 days after dose 2. Randomization codes will be unlocked for the sponsor, but blinding will be maintained at a lower level.

[0568] Determination of sample size Cohort 1: This cohort will enroll 35 participants born prematurely. This is an arbitrary sample size for generating safety data in premature infants. No statistical hypotheses will be tested with respect to this cohort. Cohort 2 will enroll a total of 912 participants: 304 in each LD and SD RSVΔNS2 / Δ1313 / I1314L(Sanofi) group, and 152 each in the HD RSVΔNS2 / Δ1313 / I1314L(Sanofi) group and the placebo group. The allocation ratio is 2:2:1:1.

[0569] Regarding the primary immunogenicity objectives With 243 evaluable participants in the LD RSVΔNS2 / Δ1313 / I1314L(Sanofi) group and 243 evaluable participants in the SD RSVΔNS2 / Δ1313 / I1314L(Sanofi) group, this study will have approximately 90% power to declare non-inferiority for the primary immunogenicity objective based on a one-sided α of 2.5%. Considering an estimated 20% attrition rate, 304 participants will be enrolled in each LD and SD RSVΔNS2 / Δ1313 / I1314L(Sanofi) group.

[0570] Regarding the main safety objectives The sample size of 152 participants in the HD RSVΔNS2 / Δ1313 / I1314L(Sanofi) group provides a 95% probability of observing an event with a true incidence of 2%, and a 78% probability of observing an event with a true incidence of 1%.

[0571] Example 4: Intranasal spray delivery device Intranasal spray delivery devices used to deliver RSV vaccine and placebo were tested to measure dose accuracy, spray droplet size distribution (DSD), spray plume geometry (PG), spray pattern (SP), and infectivity titer.

[0572] Materials and methods material Vaccine buffer solution; stored at 2°C to 8°C; kept protected from light. High-dose DP lot number 19-035-FBP / FP and low-dose DP lot number 19-054-FBP / FP; both were stored at temperatures below -60°C. MAD130 device, intranasal mucosal spray device, 1 mL syringe and vial adapter included (Teleflex), lot number 73J1700328. 3D printed poly(lactic acid) plastic dose divider; 0.1 mL, blue (in-house manufactured). RSV vaccine purified bulk.

[0573] method The methods used herein follow the guidelines of the FDA and the EMA (US Food and Drug Administration. Guidance for industry: Nasal spray and inhalation solution, suspension, and spray drug products - Chemistry, manufacturing, and controls documentation. Fed. Regist. 2002, 1-49. European Medicines Agency. Guideline on the Pharmaceutical Quality of Inhalation and Nasal Products; European Medicines Agency: London, UK, 2006; pp. 1-27).

[0574] Shot weight: To measure the dose delivery amount, weigh the amount of fluid dispensed by the pump (in this case, the syringe) during operation in a single dose.

[0575] Spray Pattern (SP): The performance of the device is characterized by measuring the uniformity of the cross-section of the spray plume at a specified distance (i.e., 30 mm) from the nozzle tip.

[0576] Spray pattern testing involves capturing a series of time-series images in a frontal view from a predetermined distance along the centerline of the spray emitted from the device, using laser irradiation and a camera. Proveris software automatically analyzes the collected image series and calculates time-averaged images, which are then used to determine the spray pattern contour and other metrics. An automated, non-impact (automated analysis combining laser beam and digital camera images) spray pattern method was used, based on the Proveris SprayVIEW® instrument platform and adapted for RSV vaccines or vaccine buffers, in accordance with FDA guidance. All spray pattern metrics were analyzed as follows: Dmax (the longest chord length connecting two points on the spray pattern contour that passes through the centroid of the contour) Dmin (the shortest chord length connecting two points on the spray pattern contour that passes through the centroid of the contour) Ellipticity (ratio of Dmax to Dmin) Area (the area enclosed by the outline of the spray pattern)

[0577] A total of 10 devices, each equipped with a total of 20 sprays, were measured. The settings used for the spray pattern analysis are detailed in Table 19 below:

[0578] [Table 75]

[0579] Plume Geometry (PG): This characterizes the performance of the device by measuring the time-averaged geometric shape (plume width and plume angle) of the spray plume when viewed in a side view at a specified distance (i.e., 30 mm) from the nozzle tip.

[0580] Plume geometry testing involves laser irradiation and a camera to capture time-series images viewed laterally along the centerline of the spray emitted from the device. These resulting images provide a visualization of the spray, and analysis allows for the determination of the duration and direction of the spray and spray particles.

[0581] Based on the Proveris SprayVIEW® instrument platform, a laser beam sheet and digital camera-based plume geometry method, adjusted for the RSV vaccine or vaccine buffer, was used. All plume geometry measures, including (2) plume width and plume angle, were analyzed according to the relevant FDA guidance documents. Plume geometry and quantified shot weight data were collected from 10 instruments, each equipped with a total of 20 sprays. The settings for the method used for plume geometry are detailed in Table 20 below. Time-averaged plume measurements were analyzed.

[0582] [Table 76]

[0583] Droplet Size Distribution (DSD): The performance of the device is characterized by measuring the spray droplet size and its distribution by laser diffraction in a fully developed steady-state phase at a specified distance (i.e., 30 mm) from the nozzle tip. By measuring the spray droplet size distribution by laser diffraction at a specified distance from the nozzle tip in a fully developed steady-state phase, it is possible to measure, for example, Dv10, Dv50, Dv90, span [(Dv90-Dv10) / Dv50], and the percentage of droplets smaller than 10 μm.

[0584] Droplet size distribution (DSD) was measured using laser diffraction, tailored to the RSV vaccine or vaccine buffer, based on the Malvern Spraytec instrument platform. All droplet size distribution (DSD) measures were performed in accordance with the FDA guidance document cited above and included the following in the analysis: Dv90: 90% of the spray particles are below this particle size in volume-based distribution. Dv50: 50% of the spray particles are below this particle size in the volume-based distribution. Dv10: In volume-based distribution, 10% of the spray particles are smaller than this particle size. %V<10μm: Volume of particles with a particle size of less than 10 microns Span: Measures the width of the distribution. The narrower the distribution, the smaller the span. The span is calculated as follows: Span = (Dv90 - Dv10) / Dv50

[0585] All samples were tested in a setup including a 3D dose divider and a primed atomizer head.

[0586] Operating mechanism and parameters Given the mechanism of a MAD Nasal® device with a dose divider, force-limited operation using Viota® single-dose software was utilized: when the force limit at the end of the stroke was reached, the software stopped operation, thereby more accurately replicating the human operation process for this particular device—the first dose was completed when the plunger hit the dose divider, and the second dose was completed when the plunger hit the hard stop on the syringe. For all tests, the following set of operating parameters (Table 21) was used.

[0587] [Table 77]

[0588] Results and Discussion Comparison of the physical properties of the test matrix The key physical properties of the RSV vaccine and vaccine buffer were compared, and dose accuracy, spray droplet size distribution (DSD), spray plume geometry (PG), and spray pattern (SP) were measured using the vaccine buffer for analysis. The comparison is shown in Table 22.

[0589] [Table 78]

[0590] The above results suggested similarities in the physical properties of DP and the formulation buffer, with the exception that the buffer matrix had a slightly lower viscosity.

[0591] Test results A total of 10 vials filled with DP (HD lot number 19-035-FP) were tested. The sample was withdrawn from each vial and then dispensed into two tubes (0.1 mL / tube #1 for the first shot, and mL / tube #2 for the second shot; for example, vial #1 becomes tubes #1 and #2, vial #2 becomes tubes #3 and #4, etc.).

[0592] Dosage accuracy based on shot weight The weight of each dose is summarized in Table 23 below. The raw results are converted to volume using a density value of 1.1377 g / mL.

[0593] [Table 79]

[0594] Dose-potency assay by plaque assay Infectivity titer is a key indicator for evaluating formulation and stability. Infectivity titer is also used in labeling RSVi doses (i.e., high-dose titer target is 6.0log). 10 The titer reading is PFU / dose (where dose = 0.2 mL). The titer reading directly correlates with viral activity; a significant decrease in viral activity is considered a decrease in infectivity titer.

[0595] [Table 80]

[0596] All titers were consistent and met the concentration requirements for a high-dose RSV vaccine.

[0597] Shot weight A second test of shot weight was conducted using a total of 10 devices (20 sprays) with an automated actuator. The results are summarized in Table 25. The maximum weight of the initial spray dose was 127.60 mg (112.07 μL in dose volume), and the minimum was 108.90 mg (95.72 μL). The average dose for the second test was 106.21 mg (102.11 μL), which was slightly less than the first dose of 121.64 mg (106.92 μL).

[0598] [Table 81]

[0599] spray pattern A total of 10 devices (20 sprays) were tested for their spray patterns. The data in Table 24 below shows an average spray area of ​​129.15 mm². 2 This indicates that the standard deviation is 14.00. The mean ellipticity is 1.25, with a standard deviation of 0.10. The mean Dmax and Dmin are 14.31 mm and 11.47 mm, respectively, with standard deviations of 0.81 and 0.96, respectively. In addition, the second dose (133.74 mm) 2 ) is, on average, the first dose (124.56 ml). 2 It showed a slightly larger spray area compared to the other dose. Overall, the first and second doses showed similar results in terms of spray area, ellipticity, Dmax, and Dmin.

[0600] [Table 82]

[0601] Plume Geometry (PG) Plume geometry and weighed shot weight data were collected simultaneously from 10 devices for a total of 20 shots. The plume geometry results were consistent across different devices and two dosages, as shown in Table 27 below.

[0602] [Table 83]

[0603] Droplet size distribution (DSD) The droplet size distribution results were consistent across different devices and between two doses. The results are provided in Table 28. The following data demonstrate that the droplet size distribution results were consistent across different devices and between two doses.

[0604] [Table 84]

[0605] Since DSD significantly affects the in vivo deposition of pharmaceuticals in the nasal cavity, DSD of nasal sprays is an important parameter for nasal formulations. Using a nasal atomizer delivery device, the average droplet diameter was Dv50 = 93.70 μm. The average percentage of small droplets (%V < 10 μm) was 0.19%, which can be considered safe, and lung deposition is negligible.

[0606] Stability during device use Tests were conducted to determine the suitability of the RSV vaccine formulation and spray delivery device for up to 24 hours at room temperature.

[0607] For this imitation study, HD or LD DP vials were thawed at room temperature for 5–7 minutes. Instrument samples were then prepared by inserting a MAD130 syringe into the thawed glass vial via a rubber stopper, removing air bubbles, and withdrawing 300 μL of DP. An atomizer was then attached and purged, reducing the volume to 200 μL to remove air from the headspace. Each prepared instrument was labeled and stored horizontally at the respective temperatures (i.e., 2°C–8°C and 25°C) for 2, 4, 6, and 24 hours. The collected samples were frozen below -60°C and sent to AnSci for PA testing. The results of the decrease in infectivity titer are shown below.

[0608] HD (≧6.7log) 10PFU / mL) and LD(≧5.7log 10 The mean logarithmic decrease / potency reduction of PFU / mL was ≤0.1 log after 24 hours at 5℃±3℃. 10 The value was PFU / mL.

[0609] HD (≧6.7log) 10 PFU / mL) and LD(≧5.7log 10 The mean logarithmic decrease / potency reduction of PFU / mL was ≤0.1 log after 6 hours at 25°C ± 2°C. 10 The value was PFU / mL; however, this was ≥0.1 log after 24 hours at 25°C ± 2°C. 10 The value was PFU / mL.

[0610] In summary, the above in-use stability data shows that both the HD and LD formulations meet the expected target infectivity titers after 6 hours of incubation at 25°C±2°C and 5°C±3°C in the MAD130 IN device.

[0611] RSVi HD and LD are recommended to be stored in the MAD130 IN device at room temperature (17°C) for up to 6 hours.

[0612] Appendix A: Summary of the array Array description Appendix A provides a list of specific sequences referenced herein. The provided amino acid sequences are from the N-terminus to the C-terminus. The nucleic acid sequences are from 5' to 3'.

[0613] [Table 85]

[0614] [Table 86]

[0615] [Table 87]

[0616] Table 88

[0617] Table 89

[0618] Table 90

[0619] Table 91

[0620] Table 92

[0621] Table 93

[0622] Table 94

[0623] Table 95

Claims

1. A method for conferring immunity to respiratory syncytial virus (RSV) infection to a child, comprising administering a certain dose of a spray RSV vaccine to the child, wherein the RSV vaccine contains an effective amount of attenuated live RSV ΔNS2 / Δ1313 / I1314L.

2. A method for conferring immunity to respiratory syncytial virus (RSV) infection to a child, comprising administering a certain dose of RSV vaccine to the child using an intranasal spray delivery device, wherein the RSV vaccine contains an effective amount of attenuated live RSV ΔNS2 / Δ1313 / I1314L.

3. A method for preventing or reducing the possibility of RSV infection in a child, or for preventing or reducing at least one symptom of RSV infection, comprising administering a certain dose of an RSV vaccine to the child, wherein the RSV vaccine contains an effective amount of attenuated live RSV ΔNS2 / Δ1313 / I1314L.

4. A method for conferring immunity to respiratory syncytial virus (RSV) infection to children, comprising administering a certain dose of a spray RSV vaccine to the children, wherein the RSV vaccine contains an effective amount of attenuated live RSV ΔNS2 / Δ1313 / I1314L, and the effective amount of RSV per dose is about 5 to about 9 log １０ It contains plaque-forming units (PFUs), and optionally the above dose is approximately 5.6 log per dose. １０ The method is PFU.

5. A method for conferring immunity to respiratory syncytial virus (RSV) infection to children, comprising administering a certain dose of a spray RSV vaccine to the children, wherein the RSV vaccine contains an effective amount of attenuated live RSV ΔNS2 / Δ1313 / I1314L, and the effective amount of RSV is approximately 5.4 log per dose. １０ PFU, approximately 5.6 logs per dose １０ PFU, approximately 6.2 logs per dose １０ PFU, approximately 6.4 log per dose １０ PFU, or approximately 7.0 log per dose １０ A method including PFU.

6. A method of conferring immunity against respiratory syncytial virus (RSV) infection to a pediatric subject, the method comprising administering a dose of an RSV vaccine to the pediatric subject, wherein the RSV vaccine comprises an effective amount of live attenuated RSV ΔNS2 / Δ1313 / I1314L, and the effective amount of the RSV comprises from about 5 to about 9 log １０ plaque forming units (PFU), and optionally the dose is from about 5.6 log １０ PFU per dose.

7. A method for conferring immunity to respiratory syncytial virus (RSV) infection to children, comprising administering a certain dose of an RSV vaccine to the children, wherein the RSV vaccine contains an effective amount of attenuated live RSV ΔNS2 / Δ1313 / I1314L, and the effective amount of RSV is approximately 5.4 log per dose. １０ PFU, approximately 5.6 logs per dose １０ Plaque-forming units (PFUs): approximately 6.2 log per dose １０ PFU, approximately 6.4 log per dose １０ PFU, or approximately 7.0 log per dose １０ A method including PFU.

8. The effective amount of the RSV is approximately 5 log １０ PFU - approximately 9 logs per dose １０ PFU, optional, approximately 5.4 logs per dose. １０ PFU, approximately 5.6 logs per dose １０ PFU, approximately 6.2 logs per dose １０ PFU, approximately 6.4 log per dose １０ PFU, or approximately 7.0 log per dose １０ The method according to any one of claims 1 to 3, comprising a PFU.

9. The method according to any one of claims 1 to 8, wherein the RSV vaccine is delivered into the nasal cavity of each nostril of the child subject at a rate of approximately half of the dose to be delivered.

10. The method according to claim 9, wherein the dose of the RSV vaccine is delivered in approximately 0.2 mL, and approximately 0.1 mL is delivered to each nostril of the pediatric subject.

11. The method according to claim 9 or 10, wherein the RSV vaccine is delivered sequentially or simultaneously to each nostril of the child subject.

12. The method according to any one of claims 1 to 11, comprising delivering a second dose of the RSV vaccine.

13. The second dose mentioned above was approximately 5.4 logs. １０ The method according to claim 12, comprising PFU.

14. The second dose mentioned above was approximately 5.6 logs. １０ The method according to claim 12, comprising PFU.

15. The second dose mentioned above was approximately 6.2 logs. １０ The method according to claim 12, comprising PFU.

16. The second dose mentioned above was approximately 6.4 logs. １０ The method according to claim 12, comprising PFU.

17. The second dose mentioned above was approximately 7.0 log １０ The method according to claim 12, comprising PFU.

18. The second dose mentioned above was approximately 5 logs. １０ PFU ~ approximately 9 logs １０ The method according to claim 12, comprising PFU.

19. The method according to any one of claims 12 to 18, wherein the second dose is administered approximately 40 to 50, 45 to 55, 55 to 60, 52 to 60, or 60 to 65 days after the first dose.

20. The method according to any one of claims 12 to 19, wherein the second dose is administered at least 56 days after the first dose.

21. The method according to any one of claims 12 to 20, wherein the second dose is delivered into the nasal cavity of each nostril of the child subject at a rate of approximately half of the delivered dose.

22. The method according to any one of claims 12 to 21, wherein the second dose of the RSV vaccine is delivered in approximately 0.2 mL, and approximately 0.1 mL is delivered to each nostril of the pediatric subject.

23. The method according to claim 21 or 22, wherein the RSV vaccine is delivered sequentially or simultaneously to each nostril of the child subject.

24. The method according to any one of claims 1 to 23, wherein the target child is approximately 6 months to approximately 22 months old.

25. The method according to any one of claims 1 to 23, wherein the target child is approximately 6 months to approximately 18 months old.

26. The method according to any one of claims 1 to 23, wherein the child subject is at least 6 months old.

27. The method according to any one of claims 1 to 23, wherein the child subject was born at full term.

28. The method according to any one of claims 1 to 23, wherein the aforementioned child subject was born prematurely.

29. The method according to any one of claims 1 and 3 to 28, wherein the dose of the RSV vaccine is administered to the pediatric subject using an intranasal spray delivery device.

30. The method according to claim 2 or 29, wherein the intranasal spray delivery device comprises a spray nozzle for spraying the RSV vaccine for administration to the pediatric subject.

31. The method according to any one of claims 2, 29, or 30, wherein the intranasal spray delivery device comprises an outer cylinder, a plunger, and a dose divider.

32. The method according to claim 31, comprising advancing the plunger within the outer cylinder by a first distance to deliver about half of the dose of the RSV vaccine to the first nostril of the pediatric subject.

33. The method according to claim 31 or 32, comprising removing the dose divider from the plunger.

34. The method according to claim 32 or 33, comprising advancing the plunger by a second distance within the outer cylinder to deliver about half of the dose to the second nostril of the pediatric subject.

35. The aforementioned intranasal spray delivery device has an average droplet diameter D of approximately 10 to 120 μm. ｖ５０ The method according to any one of claims 2 or 29 to 34, for delivering [the specified object].

36. The average droplet diameter D delivered to each nostril of the aforementioned child ｖ５０ The method according to any one of claims 2 or 29 to 34, wherein the thickness is approximately 10 to 120 μm, approximately 30 to 120 μm, approximately 50 to 110 μm, approximately 70 to 110 μm, or approximately 80 to 110 μm.

37. The method according to any one of claims 2 or 29 to 34, wherein the intranasal spray delivery device delivers an average droplet diameter Dv50 of at least 30 μm, at least 50 μm, at least 70 μm, at least 80 μm, at least 110 μm, or at least 120 μm.

38. The method according to claim 2 or any one of claims 29 to 37, wherein the average shot weight delivered to each nostril of the pediatric subject is between approximately 30 mg and approximately 200 mg, approximately 50 mg and approximately 175 mg, approximately 70 mg and approximately 160 mg, approximately 80 mg and approximately 150 mg, 95 mg and approximately 135 mg, approximately 100 mg and approximately 130 mg, approximately 100 mg and approximately 130 mg, or approximately 105 mg and approximately 130 mg.

39. The method according to any one of claims 1 to 2 or 29 to 38, wherein the average shot volume delivered to each nostril of the pediatric subject is about 85 μL to about 120 μL, about 90 μL to about 115 μL, or about 95 μL to about 115 μL.

40. The method according to any one of claims 1 to 39, wherein when the codon encoding serine at position 1313 of the L protein in the attenuated live RSV is deleted, the aforementioned deletion of an amino acid (Δ1313) occurs in the L protein.

41. The method according to any one of claims 1 to 39, wherein when the isoleucine at position 1314 in the attenuated live RSV is replaced with leucine by amino acid residue substitution, a genetically stabilizing mutation (I1314L) occurs in the L gene.

42. The aforementioned attenuated live RSV, Large polymerase protein (L), phosphoprotein (P), nucleocapsid protein (N), M2-1 protein nonstructural protein 1 (NS1), glycoprotein (G), fusion protein (F), matrix protein (M), M2-2 protein, and small hydrophobic protein (SH); and A genome or antigenome comprising a deletion of the codon encoding serine at position 1313 of the L protein, or the corresponding position; a mutation at amino acid sequence residue 1314 of the L protein, or the corresponding position, wherein the mutation at L protein amino acid sequence residue 1314 is an amino acid substitution from isoleucine to leucine, and the leucine is encoded by a codon represented as CTG; a deletion of the NS2 gene; and a nucleotide modification at position 14456 of SEQ ID NO: 1, corresponding to a change from thymine (T) to adenine (A). The method according to any one of claims 1 to 41, including the method described in any one of claims 1 to 41.

43. The method according to claim 3, wherein the at least one symptom is selected from the onset or occurrence of upper respiratory tract RSV infection, the onset or occurrence of lower respiratory tract RSV infection, the onset or occurrence of otitis media, progression of upper respiratory tract RSV infection to lower respiratory tract RSV infection, or progression to otitis media.

44. The method according to claim 3, wherein the at least one symptom is selected from asthma, wheezing, or a combination thereof.

45. Use of an intranasal spray delivery device for administering a certain dose of RSV vaccine to a child, wherein the RSV vaccine contains an effective amount of RSV ΔNS2 / Δ1313 / I1314L.

46. Use of an RSV vaccine for the manufacture of a pharmaceutical product for preventing or reducing the likelihood of infection of a child with the RSV virus, wherein the RSV vaccine contains an effective amount of RSV ΔNS2 / Δ1313 / I1314L.

47. The effective amount of the RSV is approximately 5 log １０ PFU - approximately 9 logs per dose １０ The use according to claim 45 or 46, including PFU.

48. The effective amount of the RSV is approximately 5.4 log １０ PFU, approximately 5.6 log １０ PFU, approximately 6.2 log １０ PFU, approximately 6.4 log １０ PFU, or approximately 7.0 log １０ The use according to any one of claims 41 to 43, including PFU.

49. The use according to any one of claims 45 to 48, wherein the RSV vaccine is delivered into the nasal cavity of each nostril of the child subject at a rate of approximately half of the dose to be delivered.

50. The use according to claim 49, wherein the dose of the RSV vaccine is delivered in approximately 0.2 mL, and approximately 0.1 mL is delivered to each nostril of the pediatric subject.

51. The use according to claim 49 or 50, wherein the RSV vaccine is delivered sequentially or simultaneously to each nostril of the child subject.

52. The use according to any one of claims 45 to 51, comprising delivering a second dose of the RSV vaccine.

53. The second dose mentioned above was approximately 5.4 logs. １０ The use according to claim 52, including PFU.

54. The second dose mentioned above was approximately 5.6 logs. １０ The use according to claim 52, including PFU.

55. The second dose mentioned above was approximately 6.2 logs. １０ The use according to claim 52, including PFU.

56. The second dose mentioned above was approximately 6.4 logs. １０ The use according to claim 52, including PFU.

57. The second dose mentioned above was approximately 7.0 log １０ The method according to claim 52, comprising PFU.

58. The second dose mentioned above was approximately 5 logs. １０ PFU ~ approximately 9 logs １０ The use according to claim 52, including PFU.

59. The use according to any one of claims 52 to 58, wherein the second dose is administered approximately 40 to 50, 45 to 55, 55 to 60, 52 to 60, or 60 to 65 days after the first dose.

60. The use according to any one of claims 52 to 58, wherein the second dose is administered at least 56 days after the first dose.

61. The use according to any one of claims 52 to 60, wherein the second dose is delivered into the nasal cavity of each nostril of the child subject at a rate of approximately half of the delivered dose.

62. The use according to any one of claims 52 to 61, wherein the second dose of the RSV vaccine is delivered in approximately 0.2 mL, and approximately 0.1 mL is delivered to each nostril of the pediatric subject.

63. The use according to claim 61 or 62, wherein the RSV vaccine is delivered sequentially or simultaneously to each nostril of the child subject.

64. The use according to any one of claims 45 to 63, wherein the target child is approximately 6 months to approximately 22 months old.

65. The use according to any one of claims 45 to 63, wherein the target child is approximately 6 months to approximately 18 months old.

66. The use according to any one of claims 45 to 63, wherein the child subject is at least six months old.

67. The use according to any one of claims 45 to 66, wherein the child subject is born at full term.

68. The use according to any one of claims 45 to 66, wherein the child subject is born prematurely.

69. The use according to claim 46, wherein the dose of the RSV vaccine is administered to the pediatric subject using an intranasal spray delivery device.

70. The use according to any one of claims 45 to 69, wherein the intranasal spray delivery device comprises a spray nozzle for spraying the RSV vaccine for administration to the pediatric subject.

71. The use according to any one of claims 45, 69, or 70, wherein the intranasal spray delivery device comprises an outer cylinder, a plunger, and a dose divider.

72. The use according to claim 71, comprising advancing the plunger within the outer cylinder by a first distance to deliver about half of the dose of the RSV vaccine to the first nostril of the pediatric subject.

73. The use according to claim 71 or 72, comprising advancing the plunger a second distance within the outer cylinder to deliver about half of the dose to the second nostril of the pediatric subject.

74. The aforementioned intranasal spray delivery device has an average droplet diameter D of approximately 10 to 120 μm. ｖ５０ The use according to any one of claims 45 or 69 to 73, for delivering [the specified product].

75. The average droplet diameter D delivered to each nostril of the aforementioned child ｖ５０ The use according to any one of claims 45 or 69 to 74, wherein the thickness is approximately 10 to 120 μm, approximately 30 to 120 μm, approximately 50 to 110 μm, approximately 70 to 110 μm, or approximately 80 to 110 μm.

76. The use according to any one of claims 45 or 69 to 73, wherein the intranasal spray delivery device delivers an average droplet diameter Dv50 of at least 30 μm, at least 50 μm, at least 70 μm, at least 80 μm, at least 110 μm, or at least 120 μm.

77. The use according to claim 45 or any one of claims 69 to 76, wherein the average shot weight delivered to each nostril of the pediatric subject is between approximately 30 mg and approximately 200 mg, approximately 50 mg and approximately 175 mg, approximately 70 mg and approximately 160 mg, approximately 80 mg and approximately 150 mg, 95 mg and approximately 135 mg, approximately 100 mg and approximately 130 mg, approximately 100 mg and approximately 130 mg, or approximately 105 mg and approximately 130 mg.

78. The use according to claim 45 or any one of claims 69 to 77, wherein the average shot volume delivered to each nostril of the pediatric subject is about 85 μL to about 120 μL, about 90 μL to about 115 μL, or about 95 μL to about 115 μL.

79. The use according to any one of claims 45 to 78, wherein the codon encoding serine at position 1313 of the L protein in the attenuated live RSV results in the deletion of the amino acid (Δ1313) in the L protein.

80. The use according to any one of claims 45 to 79, wherein if the isoleucine at position 1314 in the attenuated live RSV is replaced with leucine by amino acid residue substitution, a genetically stabilizing mutation (I1314L) occurs in the L gene.

81. The aforementioned attenuated live RSV, Large polymerase protein (L), phosphoprotein (P), nucleocapsid protein (N), M2-1 protein nonstructural protein 1 (NS1), glycoprotein (G), fusion protein (F), matrix protein (M), M2-2 protein, and small hydrophobic protein (SH); and A genome or antigenome comprising a deletion of the codon encoding serine at position 1313 of the L protein, or the corresponding position; a mutation at amino acid sequence residue 1314 of the L protein, or the corresponding position, wherein the mutation at L protein amino acid sequence residue 1314 is an amino acid substitution from isoleucine to leucine, and the leucine is encoded by a codon represented as CTG; a deletion of the NS2 gene; and a nucleotide modification at position 14456 of SEQ ID NO: 1, corresponding to a change from thymine (T) to adenine (A). Use according to any one of claims 45 to 80, including the use described in any one of claims 45 to 80.

82. A kit comprising a certain dose of RSV vaccine containing an effective amount of attenuated live RSV ΔNS2 / Δ1313 / I1314L, and an intranasal spray delivery device for administering the RSV vaccine to children.

83. The effective amount of the RSV is approximately 5 log １０ PFU - approximately 9 logs per dose １０ The kit according to claim 82, comprising PFU.

84. The effective amount of the RSV is approximately 5.4 log １０ PFU and / or approximately 5.6 log １０ PFU and / or approximately 6.2 log １０ PFU and / or approximately 6.4 log １０ PFU and / or approximately 7.0 log １０ A kit according to claim 82 or 83, comprising PFU.

85. The kit according to any one of claims 82 to 84, wherein the kit further comprises a second dose of the RSV vaccine.

86. The second dose is approximately 5 logs per second dose. １０ PFU ~ approximately 9 logs １０ The kit according to claim 85, comprising an effective amount of the RSV containing PFU.

87. The second dose was approximately 5.4 log per second dose. １０ PFU and / or approximately 5.6 log １０ PFU and / or approximately 6.2 log １０ PFU and / or approximately 6.4 log １０ PFU and / or approximately 7.0 log １０ The kit according to claim 85, comprising an effective amount of the RSV containing PFU.

88. The kit according to any one of claims 82 to 87, wherein the first dose and / or the second dose comprises a volume of approximately 0.2 mL.

89. The kit according to any one of claims 82 to 88, wherein the intranasal spray delivery device comprises a spray nozzle for spraying the RSV vaccine.

90. The kit according to any one of claims 82 to 89, wherein the intranasal spray delivery device comprises an outer cylinder, a plunger, and a dose divider.

91. The aforementioned intranasal spray delivery device has an average droplet diameter D of approximately 10 to 120 μm. ｖ５０ A kit according to any one of claims 82 to 90, for delivering the following:

92. The kit according to any one of claims 82 to 91, wherein the intranasal spray delivery device delivers an average droplet diameter Dv50 of at least 30 μm, at least 50 μm, at least 70 μm, at least 80 μm, at least 110 μm, or at least 120 μm.

93. The kit according to any one of claims 82 to 92, wherein the intranasal spray delivery device delivers an average shot weight of approximately 30 mg to approximately 200 mg, approximately 50 mg to approximately 175 mg, approximately 70 mg to approximately 160 mg, approximately 80 mg to approximately 150 mg, 95 mg to approximately 135 mg, approximately 100 mg to approximately 130 mg, approximately 100 mg to approximately 130 mg, or approximately 105 mg to approximately 130 mg for half dose.

94. The kit according to any one of claims 82 to 93, wherein the intranasal spray delivery device delivers an average shot volume of about 85 μL to about 120 μL, about 90 μL to about 115 μL, or about 95 μL to about 115 μL for half the dose.

95. Large polymerase protein (L), phosphoprotein (P), nucleocapsid protein (N), M2-1 protein nonstructural protein 1 (NS1), glycoprotein (G), fusion protein (F), matrix protein (M), M2-2 protein, and small hydrophobic protein (SH); and A genome or antigenome comprising a deletion of the codon encoding serine at position 1313 of the L protein, or the corresponding position; a mutation at amino acid sequence residue 1314 of the L protein, or the corresponding position, wherein the mutation at L protein amino acid sequence residue 1314 is an amino acid substitution from isoleucine to leucine, and the leucine is encoded by a codon represented as CTG; a deletion of the NS2 gene; and a nucleotide modification at position 14456 of SEQ ID NO: 1, corresponding to a change from thymine (T) to adenine (A). Recombinant infectious respiratory syncytial virus, including [specific virus name].

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