A Multicenter, Randomized, Double-blind, Placebo-controlled Phase 2b Efficacy Study of a Heterologous Prime/Boost Vaccine Regimen of Ad26.Mos4.HIV and Aluminum Phosphate-adjuvanted Clade C gp140 in Preventing HIV-1 Infection in Adult Women in Sub-Saharan Africa

The primary purpose of this study is to assess the preventive vaccine efficacy (VE), safety and tolerability of a heterologous prime/boost regimen utilizing Ad26.Mos4.HIV and aluminum-phosphate adjuvanted Clade C gp 140 for the prevention of Human Immuno Virus (HIV) infection in HIV-seronegative women residing in sub-Saharan Africa from confirmed HIV-1 infections diagnosed between the Month 7 and Month 24 visits.