Part 1: Geometric Mean Ratio (GMR) of Omicron BA.4/5 mRNA-1283.222 Over the Omicron BA.4/5 mRNA-1273.222;Part 1: GMR of the Ancestral Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) D614G mRNA-1283.222 Over the Ancestral SARS-CoV-2 D614G mRNA-1273.222;Part 1: Number of Participants with Solicited Local and Systemic Reactogenicity Adverse Reactions (ARs);Part 1: Seroresponse Rate (SRR) Difference of Omicron BA.4/5 Between mRNA-1283.222 and mRNA-1273.222;Part 1: SRR Difference of Ancestral SARS-CoV-2 D641G Between mRNA-1283.222 and mRNA-1273.222;Part 2: Number of Participants with Solicited Local and Systemic Reactogenicity ARs in Adolescents and Previously Unvaccinated Participants;Parts 1 and 2: Number of Participants with Any Serious AEs (SAEs), Medically Attended AEs (MAAEs), AEs Leading to Withdrawal From Study, and AEs of Special Interest (AESIs);Parts 1 and 2: Number of Participants with Unsolicited Adverse Events (AEs);Parts 1 and 2: rVE of mRNA-1283 and mRNA-1273 (Variant Formulations) to Prevent the First Event of COVID-19

Part 1: Geometric Mean Ratio (GMR) of Omicron BA.4/5 mRNA-1283.222 Over the Omicron BA.4/5 mRNA-1273.222;Part 1: GMR of the Ancestral Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) D614G mRNA-1283.222 Over the Ancestral SARS-CoV-2 D614G mRNA-1273.222;Part 1: Number of Participants with Solicited Local and Systemic Reactogenicity Adverse Reactions (ARs);Part 1: Seroresponse Rate (SRR) Difference of Omicron BA.4/5 Between mRNA-1283.222 and mRNA-1273.222;Part 1: SRR Difference of Ancestral SARS-CoV-2 D641G Between mRNA-1283.222 and mRNA-1273.222;Part 2: Number of Participants with Solicited Local and Systemic Reactogenicity ARs in Adolescents and Previously Unvaccinated Participants;Parts 1 and 2: Number of Participants with Any Serious AEs (SAEs), Medically Attended AEs (MAAEs), AEs Leading to Withdrawal From Study, and AEs of Special Interest (AESIs);Parts 1 and 2: Number of Participants with Unsolicited Adverse Events (AEs);Parts 1 and 2: rVE of mRNA-1283 and mRNA-1273 (Variant Formulations) to Prevent the First Event of COVID-19

Geometric Mean Ratio (GMR) of Omicron BA.4/5 mRNA-1283.222 Over the Omicron BA.4/5 mRNA-1273.222 After the Booster Dose;GMR of the Ancestral SARS-CoV-2 D614G mRNA-1283.222 Over the Ancestral SARS-CoV-2 D614G mRNA-1273.222 After the Booster Dose;Number of Participants with Any Serious AEs (SAEs), Medically Attended AEs (MAAEs), AEs Leading to Withdrawal From Study, and AEs of Special Interest (AESIs);Number of Participants with Solicited Local and Systemic Reactogenicity Adverse Reactions (ARs);Number of Participants with Unsolicited Adverse Events (AEs);rVE of mRNA-1283.222 and mRNA-1273.222 to Prevent the First Event of COVID-19;Seroresponse Rate (SRR) Difference of Omicron BA.4/5 Between mRNA-1283.222 and mRNA-1273.222 After the Booster Dose;SRR Difference of Ancestral SARS-CoV-2 D641G Between mRNA-1283.222 and mRNA-1273.222 After the Booster Dose

Geometric Mean Ratio (GMR) of Omicron BA.4/5 mRNA-1283.222 Over the Omicron BA.4/5 mRNA-1273.222 After the Booster Dose;GMR of the Ancestral SARS-CoV-2 D614G mRNA-1283.222 Over the Ancestral SARS-CoV-2 D614G mRNA-1273.222 After the Booster Dose;Number of Participants with Any Serious AEs (SAEs), Medically Attended AEs (MAAEs), AEs Leading to Withdrawal From Study, and AEs of Special Interest (AESIs);Number of Participants with Solicited Local and Systemic Reactogenicity Adverse Reactions (ARs);Number of Participants with Unsolicited Adverse Events (AEs);rVE of mRNA-1283.222 and mRNA-1273.222 to Prevent the First Event of COVID-19;Seroresponse Rate (SRR) Difference of Omicron BA.4/5 Between mRNA-1283.222 and mRNA-1273.222 After the Booster Dose;SRR Difference of Ancestral SARS-CoV-2 D641G Between mRNA-1283.222 and mRNA-1273.222 After the Booster Dose

Geometric Mean Ratio (GMR) of Omicron BA.4/5 mRNA-1283.222 Over the Omicron BA.4/5 mRNA-1273.222 After the Booster Dose;GMR of the Ancestral SARS-CoV-2 D614G mRNA-1283.222 Over the Ancestral SARS-CoV-2 D614G mRNA-1273.222 After the Booster Dose;Number of Participants with Any Serious AEs (SAEs), Medically Attended AEs (MAAEs), AEs Leading to Withdrawal From Study, and AEs of Special Interest (AESIs);Number of Participants with Solicited Local and Systemic Reactogenicity Adverse Reactions (ARs);Number of Participants with Unsolicited Adverse Events (AEs);Seroresponse Rate (SRR) Difference of Omicron BA.4/5 Between mRNA-1283.222 and mRNA-1273.222 After the Booster Dose;SRR Difference of Ancestral SARS-CoV-2 D641G Between mRNA-1283.222 and mRNA-1273.222 After the Booster Dose

Geometric Mean Ratio (GMR) of Omicron BA.4/5 mRNA-1283.222 Over the Omicron BA.4/5 mRNA-1273.222 After the Booster Dose;GMR of the Ancestral SARS-CoV-2 D614G mRNA-1283.222 Over the Ancestral SARS-CoV-2 D614G mRNA-1273.222 After the Booster Dose;Number of Participants with Any Serious AEs (SAEs), Medically Attended AEs (MAAEs), AEs Leading to Withdrawal From Study, and AEs of Special Interest (AESIs);Number of Participants with Solicited Local and Systemic Reactogenicity Adverse Reactions (ARs);Number of Participants with Unsolicited Adverse Events (AEs);Seroresponse Rate (SRR) Difference of Omicron BA.4/5 Between mRNA-1283.222 and mRNA-1273.222 After the Booster Dose;SRR Difference of Ancestral SARS-CoV-2 D641G Between mRNA-1283.222 and mRNA-1273.222 After the Booster Dose