Part A: GMT of Serum Ab Level, as Measured by Hemagglutination Inhibition (HAI) Assay for Influenza at Day 29;Part B: Geometric Mean Concentration (GMC) of Serum Ab Level, as Measured by Neutralization Assay for SARS-Cov-2 at Day 29;Part B: Percentage of Participants With Seroresponse for SARS-Cov-2 Neutralizing Abs From Baseline to Day 29;Part C: GMT Ratio of Serum RSV-A Neutralizing Abs at BD Day 29 Over GMT of serum RSV-A Neutralizing Abs at Day 29 Post Primary Dose;Part C: GMT Ratio of Serum RSV-B Neutralizing Abs at BD Day 29 Over GMT of serum RSV-B Neutralizing Abs at Day 29 Post Primary Dose;Part C: Number of Participants With MAAEs From BD Day 1 Through BD Day 181;Part C: Number of Participants With SAEs, AESIs, and AEs Leading to Withdrawal From BD Day 1 Through BD Day 361;Part C: Number of Participants with Solicited Local and Systemic ARs 7 Days post-BD;Part C: Number of Participants with Unsolicited AEs 28 Days post-BD Day 1;Parts A and B: Geometric Mean Titer (GMT) of Serum RSV-A Neutralizing Antibodies (Abs) at Day 29;Parts A and B: Number of Participants With Medically Attended AEs (MAAEs), Serious Adverse Events (SAEs), Adverse Events of Special Interest (AESIs), and AEs Leading to Withdrawal;Parts A and B: Number of Participants with Solicited Local and Systemic Adverse Reactions (ARs);Parts A and B: Number of Participants with Unsolicited Adverse Events (AEs);Parts A and B: Percentage of Participants With Seroresponse in RSV-A Neutralizing Abs From Baseline to Day 29

Part A: GMT of Serum Ab Level, as Measured by Hemagglutination Inhibition (HAI) Assay for Influenza at Day 29;Part B: Geometric Mean Concentration (GMC) of Serum Ab Level, as Measured by Neutralization Assay for SARS-Cov-2 at Day 29;Part B: Percentage of Participants With Seroresponse for SARS-Cov-2 Neutralizing Abs From Baseline to Day 29;Part C: GMT Ratio of Serum RSV-A Neutralizing Abs at BD Day 29 Over GMT of serum RSV-A Neutralizing Abs at Day 29 Post Primary Dose;Part C: GMT Ratio of Serum RSV-B Neutralizing Abs at BD Day 29 Over GMT of serum RSV-B Neutralizing Abs at Day 29 Post Primary Dose;Part C: Number of Participants With MAAEs From BD Day 1 Through BD Day 181;Part C: Number of Participants With SAEs, AESIs, and AEs Leading to Withdrawal From BD Day 1 Through BD Day 361;Part C: Number of Participants with Solicited Local and Systemic ARs 7 Days post-BD;Part C: Number of Participants with Unsolicited AEs 28 Days post-BD Day 1;Parts A and B: Geometric Mean Titer (GMT) of Serum RSV-A Neutralizing Antibodies (Abs) at Day 29;Parts A and B: Number of Participants With Medically Attended AEs (MAAEs), Serious Adverse Events (SAEs), Adverse Events of Special Interest (AESIs), and AEs Leading to Withdrawal;Parts A and B: Number of Participants with Solicited Local and Systemic Adverse Reactions (ARs);Parts A and B: Number of Participants with Unsolicited Adverse Events (AEs);Parts A and B: Percentage of Participants With Seroresponse in RSV-A Neutralizing Abs From Baseline to Day 29

Geometric Mean Concentration (GMC) of Serum Ab Level, as Measured by Neutralization Assay for SARS-Cov-2 at Day 29;Geometric Mean Titer (GMT) of Serum RSV-A Neutralizing Antibodies (Abs) at Day 29;GMT of Serum Ab Level, as Measured by Hemagglutination Inhibition (HAI) Assay for Influenza at Day 29;Number of Participants With Medically Attended AEs (MAAEs), Serious Adverse Events (SAEs), Adverse Events of Special Interest (AESIs), and AEs Leading to Withdrawal;Number of Participants with Solicited Local and Systemic Adverse Reactions (ARs);Number of Participants with Unsolicited Adverse Events (AEs);Percentage of Participants With Seroresponse for SARS-Cov-2 Neutralizing Abs From Baseline to Day 29;Percentage of Participants With Seroresponse in RSV-A Neutralizing Abs From Baseline to Day 29

Geometric Mean Concentration (GMC) of Serum Ab Level, as Measured by Neutralization Assay for SARS-Cov-2 at Day 29;Geometric Mean Titer (GMT) of Serum RSV-A Neutralizing Antibodies (Abs) at Day 29;GMT of Serum Ab Level, as Measured by Hemagglutination Inhibition (HAI) Assay for Influenza at Day 29;Number of Participants With Medically Attended AEs (MAAEs), Serious Adverse Events (SAEs), Adverse Events of Special Interest (AESIs), and AEs Leading to Withdrawal;Number of Participants with Solicited Local and Systemic Adverse Reactions (ARs);Number of Participants with Unsolicited Adverse Events (AEs);Percentage of Participants With Seroresponse for SARS-Cov-2 Neutralizing Abs From Baseline to Day 29;Percentage of Participants With Seroresponse in RSV-A Neutralizing Abs From Baseline to Day 29