An AE is any untoward medical occurrence in a participant participating in a clinical study that does not necessarily have a causal relationship with the pharmaceutical/biological agent under study. An SAE is an AE resulting in any of the following outcomes or deemed significant for any other reason: death; initial or prolonged inpatient hospitalization; life-threatening experience (immediate risk of dying); persistent or significant disability/incapacity; congenital anomaly/birth defect; suspected transmission of any infectious agent via a medicinal product or medically important. The outcome measure was planned to be analyzed for specified arms only.

The full analysis set (FAS) included all participants who were randomized and received at least one dose of vaccine (active or placebo), regardless of the occurrence of protocol deviations or the type of vaccine.

An AE is any untoward medical occurrence in a participant participating in a clinical study that does not necessarily have a causal relationship with the pharmaceutical/biological agent under study. An SAE is an AE resulting in any of the following outcomes or deemed significant for any other reason: death; initial or prolonged inpatient hospitalization; life-threatening experience (immediate risk of dying); persistent or significant disability/incapacity; congenital anomaly/birth defect; suspected transmission of any infectious agent via a medicinal product or medically important. The outcome measure was planned to be analyzed for specified arms only.

The full analysis set (FAS) included all participants who were randomized and received at least one dose of vaccine (active or placebo), regardless of the occurrence of protocol deviations or the type of vaccine.

An AE is any untoward medical occurrence in a participant participating in a clinical study that does not necessarily have a causal relationship with the pharmaceutical/biological agent under study. An SAE is an AE resulting in any of the following outcomes or deemed significant for any other reason: death; initial or prolonged inpatient hospitalization; life-threatening experience (immediate risk of dying); persistent or significant disability/incapacity; congenital anomaly/birth defect; suspected transmission of any infectious agent via a medicinal product or medically important. The outcome measure was planned to be analyzed for specified arms only.

The FAS included all participants who were randomized and received at least one dose of vaccine (active or placebo), regardless of the occurrence of protocol deviations or the type of vaccine.

An AE is any untoward medical occurrence in a participant participating in a clinical study that does not necessarily have a causal relationship with the pharmaceutical/biological agent under study. An SAE is an AE resulting in any of the following outcomes or deemed significant for any other reason: death; initial or prolonged inpatient hospitalization; life-threatening experience (immediate risk of dying); persistent or significant disability/incapacity; congenital anomaly/birth defect; suspected transmission of any infectious agent via a medicinal product or medically important. The outcome measure was planned to be analyzed for specified arms only.

The FAS included all participants who were randomized and received at least one dose of vaccine (active or placebo), regardless of the occurrence of protocol deviations or the type of vaccine.

Number of participants with solicited local and systemic AEs at 7 days post-vaccination 1 in Cohort 1 were reported. An AE is any untoward medical occurrence in a participant participating in a clinical study that does not necessarily have a causal relationship with the pharmaceutical/biological agent under study. Solicited local (injection site) AEs that included injection site pain/tenderness, erythema and swelling at the study vaccine injection site, are used to assess the reactogenicity of the study vaccine and are pre-defined local (injection site). Systemic events included events such as fatigue, headache, nausea, and myalgia, for which participants were specifically questioned and which will be noted by participants in their participant diary for 7 days post-vaccination (day of vaccination and the subsequent 7 days).

The FAS included all participants who were randomized and received at least one dose of vaccine (active or placebo), regardless of the occurrence of protocol deviations or the type of vaccine.

Number of participants with solicited local and systemic AEs at 7 days post-vaccination 2 in Cohort 1 were reported. An AE is any untoward medical occurrence in a participant participating in a clinical study that does not necessarily have a causal relationship with the pharmaceutical/biological agent under study. Solicited local AEs that included injection site pain/tenderness, erythema and swelling at the study vaccine injection site, are used to assess the reactogenicity of the study vaccine and are pre-defined local (injection site). Systemic events included events such as fatigue, headache, nausea, and myalgia, for which participants will be specifically questioned and which were noted by participants in their participant diary for 7 days post vaccination (day of vaccination and the subsequent 7 days).

The FAS included all participants who were randomized and received at least one dose of vaccine (active or placebo), regardless of the occurrence of protocol deviations or the type of vaccine. Here, 'N' (number of participants analyzed) signifies participants evaluable for this outcome measure.

Number of participants with solicited local and systemic AEs at 7 days post-vaccination 3 in Cohort 1 were reported. An AE is any untoward medical occurrence in a participant participating in a clinical study that does not necessarily have a causal relationship with the pharmaceutical/biological agent under study. Solicited local AEs that included injection site pain/tenderness, erythema and swelling at the study vaccine injection site, are used to assess the reactogenicity of the study vaccine and are pre-defined local (injection site). Systemic events included events such as fatigue, headache, nausea, and myalgia, for which participants were specifically questioned and which will be noted by participants in their participant diary for 7 days post vaccination (day of vaccination and the subsequent 7 days).

The FAS included all participants who were randomized and received at least one dose of vaccine (active or placebo), regardless of the occurrence of protocol deviations or the type of vaccine. Here, 'N' (number of participants analyzed) signifies participants evaluable for this outcome measure.

Number of participants with solicited local and systemic AEs at 7 days post-vaccination 1 in Cohort 2 were reported. An AE is any untoward medical occurrence in a participant participating in a clinical study that does not necessarily have a causal relationship with the pharmaceutical/biological agent under study. Solicited local AEs that included injection site pain/tenderness, erythema and swelling at the study vaccine injection site, are used to assess the reactogenicity of the study vaccine and are pre-defined local (injection site). Systemic events included events such as fatigue, headache, nausea, and myalgia, for which participants were specifically questioned and which will be noted by participants in their participant diary for 7 days post vaccination (day of vaccination and the subsequent 7 days).

The FAS included all participants who were randomized and received at least one dose of vaccine (active or placebo), regardless of the occurrence of protocol deviations or the type of vaccine.

Number of participants with solicited local and systemic AEs at 7 days post-vaccination 2 in Cohort 2 were reported. An AE is any untoward medical occurrence in a participant participating in a clinical study that does not necessarily have a causal relationship with the pharmaceutical/biological agent under study. Solicited local AEs that included injection site pain/tenderness, erythema and swelling at the study vaccine injection site, are used to assess the reactogenicity of the study vaccine and are pre-defined local (injection site). Systemic events included events such as fatigue, headache, nausea, and myalgia, for which participants were specifically questioned and which will be noted by participants in their participant diary for 7 days post vaccination (day of vaccination and the subsequent 7 days).

The FAS included all participants who were randomized and received at least one dose of vaccine (active or placebo), regardless of the occurrence of protocol deviations or the type of vaccine. Here, 'N' (number of participants analyzed) signifies participants evaluable for this outcome measure.

Number of participants with solicited local and systemic AEs at 7 days post-vaccination 1 in Cohort 3 were reported. An AE is any untoward medical occurrence in a participant participating in a clinical study that does not necessarily have a causal relationship with the pharmaceutical/biological agent under study. Solicited local AEs that included injection site pain/tenderness, erythema and swelling at the study vaccine injection site, are used to assess the reactogenicity of the study vaccine and are pre-defined local (injection site). Systemic events included events such as fatigue, headache, nausea, and myalgia, for which participants were specifically questioned and which will be noted by participants in their participant diary for 7 days post vaccination (day of vaccination and the subsequent 7 days).

The FAS included all participants who were randomized and received at least one dose of vaccine (active or placebo), regardless of the occurrence of protocol deviations or the type of vaccine. Here, 'N' (number of participants analyzed) signifies participants evaluable for this outcome measure.

Number of participants with solicited local and systemic AEs at 7 days post-vaccination 2 in Cohort 3 were reported. An AE is any untoward medical occurrence in a participant participating in a clinical study that does not necessarily have a causal relationship with the pharmaceutical/biological agent under study. Solicited local AEs that included injection site pain/tenderness, erythema and swelling at the study vaccine injection site, are used to assess the reactogenicity of the study vaccine and are pre-defined local (injection site). Systemic events included events such as fatigue, headache, nausea, and myalgia, for which participants were specifically questioned and which will be noted by participants in their participant diary for 7 days post vaccination (day of vaccination and the subsequent 7 days).

The FAS included all participants who were randomized and received at least one dose of vaccine (active or placebo), regardless of the occurrence of protocol deviations or the type of vaccine. Here, 'N' (number of participants analyzed) signifies participants evaluable for this outcome measure.

Number of participants with solicited local and systemic AEs at 7 days post-vaccination 3 in Cohort 3 were reported. An AE is any untoward medical occurrence in a participant participating in a clinical study that does not necessarily have a causal relationship with the pharmaceutical/biological agent under study. Solicited local AEs that included injection site pain/tenderness, erythema and swelling at the study vaccine injection site, are used to assess the reactogenicity of the study vaccine and are pre-defined local (injection site). Systemic events included events such as fatigue, headache, nausea, and myalgia, for which participants were specifically questioned and which will be noted by participants in their participant diary for 7 days post vaccination (day of vaccination and the subsequent 7 days).

The FAS included all participants who were randomized and received at least one dose of vaccine (active or placebo), regardless of the occurrence of protocol deviations or the type of vaccine. Here, 'N' (number of participants analyzed) signifies participants evaluable for this outcome measure.

Number of participants with unsolicited AEs post-vaccination 1 in Cohort 1 were reported. An AE is any untoward medical occurrence in a participant participating in a clinical study that does not necessarily have a causal relationship with the pharmaceutical/biological agent under study. Unsolicited AEs are all AEs for which the participant is not specifically questioned in the participant diary.

The FAS included all participants who were randomized and received at least one dose of vaccine (active or placebo), regardless of the occurrence of protocol deviations or the type of vaccine.

Number of participants with unsolicited AEs post-vaccination 2 in Cohort 1 were reported. An AE is any untoward medical occurrence in a participant participating in a clinical study that does not necessarily have a causal relationship with the pharmaceutical/biological agent under study. Unsolicited AEs are all AEs for which the participant is not specifically questioned in the participant diary.

The FAS included all participants who were randomized and received at least one dose of vaccine (active or placebo), regardless of the occurrence of protocol deviations or the type of vaccine. Here, 'N' (number of participants analyzed) signifies participants evaluable for this outcome measure.

Number of participants with unsolicited AEs post-vaccination 3 in Cohort 1 were reported. An AE is any untoward medical occurrence in a participant participating in a clinical study that does not necessarily have a causal relationship with the pharmaceutical/biological agent under study. Unsolicited AEs are all AEs for which the participant is not specifically questioned in the participant diary.

The FAS included all participants who were randomized and received at least one dose of vaccine (active or placebo), regardless of the occurrence of protocol deviations or the type of vaccine. Here, 'N' (number of participants analyzed) signifies participants evaluable for this outcome measure.

Number of participants with unsolicited AEs post-vaccination 1 in Cohort 2 were reported. An AE is any untoward medical occurrence in a participant participating in a clinical study that does not necessarily have a causal relationship with the pharmaceutical/biological agent under study. Unsolicited AEs are all AEs for which the participant is not specifically questioned in the participant diary.

The FAS included all participants who were randomized and received at least one dose of vaccine (active or placebo), regardless of the occurrence of protocol deviations or the type of vaccine.

Number of participants with unsolicited AEs post-vaccination 2 in Cohort 2 were reported. An AE is any untoward medical occurrence in a participant participating in a clinical study that does not necessarily have a causal relationship with the pharmaceutical/biological agent under study. Unsolicited AEs are all AEs for which the participant is not specifically questioned in the participant diary.

The FAS included all participants who were randomized and received at least one dose of vaccine (active or placebo), regardless of the occurrence of protocol deviations or the type of vaccine. Here, 'N' (number of participants analyzed) signifies participants evaluable for this outcome measure.

Number of participants with unsolicited AEs post-vaccination 1 in Cohort 3 were reported. An AE is any untoward medical occurrence in a participant participating in a clinical study that does not necessarily have a causal relationship with the pharmaceutical/biological agent under study. Unsolicited AEs are all AEs for which the participant is not specifically questioned in the participant diary.

The FAS included all participants who were randomized and received at least one dose of vaccine (active or placebo), regardless of the occurrence of protocol deviations or the type of vaccine. Here, 'N' (number of participants analyzed) signifies participants evaluable for this outcome measure.

Number of participants with unsolicited AEs post-vaccination 2 in Cohort 3 were reported. An AE is any untoward medical occurrence in a participant participating in a clinical study that does not necessarily have a causal relationship with the pharmaceutical/biological agent under study. Unsolicited AEs are all AEs for which the participant is not specifically questioned in the participant diary.

The FAS included all participants who were randomized and received at least one dose of vaccine (active or placebo), regardless of the occurrence of protocol deviations or the type of vaccine. Here, 'N' (number of participants analyzed) signifies participants evaluable for this outcome measure.

Number of participants with unsolicited AEs post-vaccination 3 in Cohort 3 were reported. An AE is any untoward medical occurrence in a participant participating in a clinical study that does not necessarily have a causal relationship with the pharmaceutical/biological agent under study. Unsolicited AEs are all AEs for which the participant is not specifically questioned in the participant diary.

The FAS included all participants who were randomized and received at least one dose of vaccine (active or placebo), regardless of the occurrence of protocol deviations or the type of vaccine. Here, 'N' (number of participants analyzed) signifies participants evaluable for this outcome measure.

RSV A2 Strain neutralization antibody titers on Day 29 was reported. Geometric mean titers (GMTs) of RSV A2 neutralizing antibodies were measured using the neutralization assay. The outcome measure was planned to be analyzed for specified arms only.

The per-protocol RSV immunogenicity (PPI) set included all participants who were randomized and received the complete first dose and for whom immunogenicity data were available. Here, 'N' (number of participants analyzed) signifies participants evaluable for this outcome measure.

RSV A2 strain neutralization antibody titers at specified timepoints in Cohort 1 was reported. The GMTs of RSV A2 neutralizing antibodies were measured using the neutralization assay.

PPI set included all participants who were randomized and received the complete first dose and for whom immunogenicity data were available. Here, 'N' (number of participants analyzed) signifies participants evaluable for this outcome measure. Here, 'n' (number analyzed) signifies participants evaluable for this outcome measure at specified timepoints.

RSV A2 strain neutralization antibody titers at specified timepoints in Cohort 3 was reported. The GMTs of RSV A2 neutralizing antibodies were measured using the neutralization assay.

PPI set included all participants who were randomized and received the complete first dose and for whom immunogenicity data were available. Here, 'N' (number of participants analyzed) signifies participants evaluable for this outcome measure. Here, 'n' (number analyzed) signifies participants evaluable for this outcome measure at specified timepoints.

RSV A2 strain neutralization antibody titers on Day 29 in Group 16 of Cohort 2 was reported. The GMTs of RSV A2 neutralizing antibodies were measured using the neutralization assay. The outcome measure was planned to be reported for specified arms only.

PPI set included all participants who were randomized and received the complete first dose and for whom immunogenicity data were available. Here, 'N' (number of participants analyzed) signifies participants evaluable for this outcome measure.

RSV A2 strain neutralization antibody titers on Day 85 in Group 17 of Cohort 2 was reported. The GMTs of RSV A2 neutralizing antibodies were measured using the neutralization assay. The outcome measure was planned to be reported for specified arms only.

PPI set included all participants who were randomized and received the complete first dose and for whom immunogenicity data were available. Here, 'N' (number of participants analyzed) signifies participants evaluable for this outcome measure.

GMT (ELISA units per liter [EU/L]) of RSV F-protein in pre-fusion form as assessed by ELISA at specified timepoints as assessed by ELISA at specified timepoints in Cohort 1 were reported.

PPI set included all participants who were randomized and received the complete first dose and for whom immunogenicity data were available. Here, 'n' (number analyzed) signifies participants evaluable for this outcome measure at specified timepoints.

GMT (ELISA units per liter [EU/L]) of RSV F-protein in pre-fusion form as assessed by ELISA at specified timepoints as assessed by ELISA at specified timepoints in Cohort 2 were reported.

PPI set included all participants who were randomized and received the complete first dose and for whom immunogenicity data were available. Here, 'n' (number analyzed) signifies participants evaluable for this outcome measure at specified timepoints.

GMT (EU/L) of RSV F-protein in post-fusion form as assessed by ELISA at specified timepoints for Cohort 1 were reported.

PPI set included all participants who were randomized and received the complete first dose and for whom immunogenicity data were available. Here, 'n' (number analyzed) signifies participants evaluable for this outcome measure at specified timepoints.

GMT (EU/L) of RSV F-protein in post-fusion form as assessed by ELISA at specified timepoints for Cohort 2 were reported.

PPI set included all participants who were randomized and received the complete first dose and for whom immunogenicity data were available. Here, 'n' (number analyzed) signifies participants evaluable for this outcome measure at specified timepoints.

Breadth of IFN-gamma T-Cells responses against RSV analyzed by ELISpot assay at specified timepoints for Cohort 1 were reported. The ELISPOT assay for F protein-specific gamma interferon-producing T cells was performed using RSV F peptides. The unit was Spot forming units (SFU)/10^6 peripheral blood mononuclear cells (PBMCs).

PPI set included all participants who were randomized and received the complete first dose and for whom immunogenicity data were available. Here, 'n' (number analyzed) signifies participants evaluable for this outcome measure at specified timepoints.

Breadth of IFN-gamma T-Cells responses against RSV analyzed by ELISpot assay at specified timepoints for Cohort 3 were reported. The ELISPOT assay for F protein-specific gamma interferon-producing T cells was performed using RSV F peptides. The unit was SFU/10^6 PBMCs.

PPI set included all participants who were randomized and received the complete first dose and for whom immunogenicity data were available. Here, 'N' (number of participants analyzed) signifies participants evaluable for this outcome measure. Here, 'n' (number analyzed) signifies participants evaluable for this outcome measure at specified timepoints.

Breadth of IFN-gamma T-Cells responses against RSV analyzed by ELISpot Assay on Day 29 in Groups 11-16 of Cohort 2 was reported. The ELISPOT assay for F protein-specific gamma interferon-producing T cells was performed using RSV F peptides. The outcome measure was planned to be analyzed for specified arms only.

The PPI set included all participants who were randomized and received the complete first dose and for whom immunogenicity data were available. Here, 'N' (number of participants analyzed) signifies participants evaluable for this outcome measure.

Breadth of IFN-gamma T-Cells responses analyzed by ELISpot assay on Day 85 in Group 17 of Cohort 2 was reported. The ELISPOT assay for F protein-specific gamma interferon-producing T cells was performed using RSV F peptides. The outcome measure was planned to be analyzed for specified arms only.

PPI set included all participants who were randomized and received the complete first dose and for whom immunogenicity data were available. Here, 'N' (number of participants analyzed) signifies participants evaluable for this outcome measure.