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

Inclusion Criteria: * Confirmed human immunodeficiency virus (HIV)-1 infected and started antiretroviral therapy (ART) during acute infection (Fiebig stages I, II, III or IV) as part of trial RV254 * Treatment with current stable antiretroviral therapy (ART) (no changes to treatment) for at least 4 weeks prior to screening * All female participants of childbearing potential must have a negative serum pregnancy test (beta human chorionic gonadotropin) at the screening visit, and a negative urine pregnancy test prior to vaccination on Day 1 and prior to subsequent study vaccinations * HIV ribonucleic acid (RNA) less than (\<)50 copies per milliliter (copies/ml) for at least 48 weeks at screening: a) One blip of HIV RNA greater than (\>)50 and \<200 copies/ml within 48 weeks is acceptable, provided that the most recent (before screening) HIV RNA \<50 copies/ml * Laboratory criteria during screening: a) Hemoglobin: Women: greater than or equal to \>=11 gram/deciliter (g/dL); Men \>=12.5 g/dL, b) White cell count: 2,500 to 11,000 cells per cubic millimeter (cells/mm\^3), c) Platelets: 125,000 to 450,000 per mm\^3, d) Alanine aminotransferase (ALT)/aspartate aminotransferase (AST) less than or equal to \<=1.5x institutional upper limits of normal (ULN), e) Creatinine \<=1.5x institutional ULN, f) CD4 \> 400 cells/mm\^3, g) Troponin \<1x ULN * A woman must be either: a) Not of childbearing potential: postmenopausal (\>45 years of age with amenorrhea for at least 2 years, or any age…