Safety and Efficacy Study of Vaccine Schedule With Ad26.Mos.HIV and MVA-Mosaic in Human Immunodeficiency Virus (HIV)-Infected Adults

The purpose of the study is to assess: 1 safety and tolerability of adenovirus serotype 26 (Ad26) prime and Modified Vaccinia Ankara (MVA) boost versus placebo in participants on suppressive antiretroviral therapy (ART) that was initiated during acute Human Immunodeficiency Virus (HIV) infection; 2) Measure the frequency and duration of sustained viremic control after receiving Ad26 prime/MVA boost or placebo, defined as greater than 24 weeks with plasma HIV ribonucleic acid (RNA) lesser than (\<)50 copies/ml after antiretroviral (ARV) analytical treatment interruption (ATI).