Inclusion Criteria:

- Is an adult aged ≥18 years or an adolescent aged 12 to <18 years and weighs at least
40 kg at the time of Screening.

- Tests negative for current SARS-CoV-2 infection by local antigen test or RT-PCR at
the time of Screening.

- For Cohort A, has significant immune compromise from causes including solid tumor or
hematologic malignancies, chimeric antigen receptor (CAR)-T-cell therapy or
hematopoietic stem cell transplant, primary immunodeficiency, advanced HIV
infection, or receiving qualifying immunosuppressive therapies.

- For Cohort B, is at risk of acquiring SARS-CoV-2 due to regular unmasked
face-to-face interactions in indoor settings.

- Agrees to defer receipt of any COVID-19 vaccination or booster for a minimum of 28
days after dosing.

- Note: unless specified by Cohort, the criteria apply to both Cohorts

Exclusion Criteria:

- For Cohort B: Prior receipt of a COVID-19 vaccine or booster within 120 days before
randomization.

- Prior receipt of convalescent plasma or a mAb to SARS-CoV-2 active against currently
circulating variants, including in the setting of a clinical trial, within 120 days
before randomization.

- Prior known or suspected SARS-CoV-2 infection within 120 days before randomization.

- Exposure to someone with known or suspected SARS-CoV-2 infection in the 5 days
before randomization.

- Is acutely ill or has any symptoms suggestive of infection, in the opinion of the
Investigator.

Note 1: Other protocol defined inclusion/exclusion criteria apply Note 2: Unless
specified by Cohort, the criteria apply to both Cohorts