Key Inclusion Criteria:  Incidence Phase  HIV-1 status unknown at initial screening and no prior human immunodeficiency virus ( HIV)-1 testing within the last 3 months Sexually active (has had > 1 vaginal intercourse within the last 3 months) with cisgender male individuals (CGM)  Randomized Phase  Negative fourth generation HIV-1 antibody (Ab)/antigen (Ag) test confirmed with central HIV-1 testing Estimated glomerular filtration rate (GFR) ≥ 60 mL/min at screening Body weight ≥ 35 kg  Key Exclusion Criteria:  Prior receipt of an HIV vaccine Prior use of long-acting systemic pre-exposure prophylaxis (PrEP)  Note: Other protocol defined Inclusion/Exclusion criteria may apply.