Part A: Geometric Mean Concentration (GMC) of Serum SARS-CoV-2-Specific Neutralizing Antibody (nAb) After the Second Dose in Unvaccinated Participants;Part A: GMC of SARS-CoV-2-Specific nAb 28 Days After Dose 3;Part B: GMC of SARS-CoV-2-Specific nAb 28 Days After the BD in SOT Participants Who Received the Moderna Primary Series and Non-Moderna Primary Series;Parts A and B: Number of Healthy Participants With AESIs, Including Myocarditis/Pericarditis;Parts A and B: Number of Healthy Participants With AEs Leading to Discontinuation From Dosing and/or Study Participation (Withdrawal);Parts A and B: Number of Healthy Participants With Biopsy-Proven Organ Rejection;Parts A and B: Number of Healthy Participants With MAAEs;Parts A and B: Number of Healthy Participants With SAEs;Parts A and B: Number of Healthy Participants With Solicited Local and Systemic ARs;Parts A and B: Number of Healthy Participants With Unsolicited AEs;Parts A and B: Number of SOT Participants With Adjudicated Biopsy-Proven Organ Rejection;Parts A and B: Number of SOT Participants With Adverse Event of Special Interests (AESIs), Including Myocarditis/Pericarditis;Parts A and B: Number of SOT Participants With AEs Leading to Discontinuation From Dosing and/or Study Participation (Withdrawal);Parts A and B: Number of SOT Participants With Medically-Attended Adverse Events (MAAEs);Parts A and B: Number of SOT Participants With Serious Adverse Events (SAEs);Parts A and B: Number of SOT Participants With Solicited Local and Systemic Adverse Reactions (ARs);Parts A and B: Number of SOT Participants With Unsolicited Adverse Events (AEs)

Part A: Geometric Mean Concentration (GMC) of Serum SARS-CoV-2-Specific Neutralizing Antibody (nAb) After the Second Dose in Unvaccinated Participants;Part A: GMC of SARS-CoV-2-Specific nAb 28 Days After Dose 3;Part B: GMC of SARS-CoV-2-Specific nAb 28 Days After the BD in SOT Participants Who Received the Moderna Primary Series and Non-Moderna Primary Series;Parts A and B: Number of Healthy Participants With AESIs, Including Myocarditis/Pericarditis;Parts A and B: Number of Healthy Participants With AEs Leading to Discontinuation From Dosing and/or Study Participation (Withdrawal);Parts A and B: Number of Healthy Participants With Biopsy-Proven Organ Rejection;Parts A and B: Number of Healthy Participants With MAAEs;Parts A and B: Number of Healthy Participants With SAEs;Parts A and B: Number of Healthy Participants With Solicited Local and Systemic ARs;Parts A and B: Number of Healthy Participants With Unsolicited AEs;Parts A and B: Number of SOT Participants With Adjudicated Biopsy-Proven Organ Rejection;Parts A and B: Number of SOT Participants With Adverse Event of Special Interests (AESIs), Including Myocarditis/Pericarditis;Parts A and B: Number of SOT Participants With AEs Leading to Discontinuation From Dosing and/or Study Participation (Withdrawal);Parts A and B: Number of SOT Participants With Medically-Attended Adverse Events (MAAEs);Parts A and B: Number of SOT Participants With Serious Adverse Events (SAEs);Parts A and B: Number of SOT Participants With Solicited Local and Systemic Adverse Reactions (ARs);Parts A and B: Number of SOT Participants With Unsolicited Adverse Events (AEs)

Geometric Mean Titer (GMT) of SARS-CoV-2 Specific Neutralizing Antibody (nAb) for Participants in Part A;GMT of SARS-CoV-2 Specific nAB for Participants in Part B;Number of Participants with AEs Leading to Withdrawal;Number of Participants with AEs of Special Interest (AESIs);Number of Participants with Biopsy-Proven Organ Rejection;Number of Participants with Medically-Attended AEs (MAAEs);Number of Participants with Serious AEs (SAEs);Number of Participants with Solicited Local and Systemic Adverse Reactions (ARs) in Part A;Number of Participants with Solicited Local and Systemic ARs in Part B;Number of Participants with Unsolicited Adverse Events (AEs) in Part A;Number of Participants with Unsolicited AEs in Part B

Geometric Mean Titer (GMT) of SARS-CoV-2 Specific Neutralizing Antibody (nAb) for Participants in Part A;GMT of SARS-CoV-2 Specific nAB for Participants in Part B;Number of Participants with AEs Leading to Withdrawal;Number of Participants with AEs of Special Interest (AESIs);Number of Participants with Biopsy-Proven Organ Rejection;Number of Participants with Medically-Attended AEs (MAAEs);Number of Participants with Serious AEs (SAEs);Number of Participants with Solicited Local and Systemic Adverse Reactions (ARs) in Part A;Number of Participants with Solicited Local and Systemic ARs in Part B;Number of Participants with Unsolicited Adverse Events (AEs) in Part A;Number of Participants with Unsolicited AEs in Part B

Geometric Mean Titer (GMT) of SARS-CoV-2 Specific Neutralizing Antibody (nAb) for Participants;Number of Participants with AEs Leading to Withdrawal;Number of Participants with AEs of Special Interest (AESIs);Number of Participants with Biopsy-Proven Organ Rejection;Number of Participants with Medically-Attended AEs (MAAEs);Number of Participants with Serious AEs (SAEs);Number of Participants with Solicited Local and Systemic Adverse Reactions (ARs);Number of Participants with Unsolicited Adverse Events (AEs)

Geometric Mean Titer (GMT) of SARS-CoV-2 Specific Neutralizing Antibody (nAb) for Participants;Number of Participants with AEs Leading to Withdrawal;Number of Participants with AEs of Special Interest (AESIs);Number of Participants with Biopsy-Proven Organ Rejection;Number of Participants with Medically-Attended AEs (MAAEs);Number of Participants with Serious AEs (SAEs);Number of Participants with Solicited Local and Systemic Adverse Reactions (ARs);Number of Participants with Unsolicited Adverse Events (AEs)

Geometric Mean Titer (GMT) of SARS-CoV-2 Specific Neutralizing Antibody (nAb);Number of Participants with Adverse Events (AEs) Leading to Withdrawal;Number of Participants with Adverse Events of Special Interest (AESIs);Number of Participants with Biopsy-proven Organ Rejection;Number of Participants with Medically-Attended AEs (MAAEs);Number of Participants with Serious Adverse Events (SAEs);Number of Participants with Solicited Local and Systemic Adverse Reactions (ARs);Number of Participants with Unsolicited Adverse Events (AEs)

Geometric Mean Titer (GMT) of SARS-CoV-2 Specific Neutralizing Antibody (nAb);Number of Participants with Adverse Events (AEs) Leading to Withdrawal;Number of Participants with Adverse Events of Special Interest (AESIs);Number of Participants with Biopsy-proven Organ Rejection;Number of Participants with Medically-Attended AEs (MAAEs);Number of Participants with Serious Adverse Events (SAEs);Number of Participants with Solicited Local and Systemic Adverse Reactions (ARs);Number of Participants with Unsolicited Adverse Events (AEs)

Geometric Mean Titer (GMT) of SARS-CoV-2 Specific Neutralizing Antibody (nAb);Number of Participants with Adverse Events (AEs) Leading to Withdrawal;Number of Participants with Biopsy-proven Organ Rejection;Number of Participants with Medically-Attended AEs (MAAEs);Number of Participants with Serious Adverse Events (SAEs);Number of Participants with Solicited Local and Systemic Adverse Reactions (ARs);Number of Participants with Unsolicited Adverse Events (AEs)

Geometric Mean Titer (GMT) of SARS-CoV-2 Specific Neutralizing Antibody (nAb);Number of Participants with Adverse Events (AEs) Leading to Withdrawal;Number of Participants with Biopsy-proven Organ Rejection;Number of Participants with Medically-Attended AEs (MAAEs);Number of Participants with Serious Adverse Events (SAEs);Number of Participants with Solicited Local and Systemic Adverse Reactions (ARs);Number of Participants with Unsolicited Adverse Events (AEs)