A Study to Investigate the Prevention of COVID-19 withVYD222 in Adults With Immune Compromise and in Participants Aged 12 Years or Older Who Are at Risk of Exposure to SARS-CoV-2

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