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 with amenorrhea for at least 6 months and a serum follicle stimulation hormone [FSH] level >40 International Units Per Liter (IU/L); surgically sterile; or b) Of child-bearing potential and practicing an effective double method of birth control (example, prescription oral contraceptives, contraceptive injections, intrauterine device, contraceptive patch, or vaginal ring, in conjunction with either a female condom or one of the methods for male contraception before entry and through 3 months after the last vaccination

Exclusion Criteria:

• Receipt of any vaccine within 30 days prior to the first vaccination or plans to receive within 30 days post-vaccination. In the case of medically indicated vaccines, the vaccination should be given at least 2 weeks before or after the first vaccination. However, if a vaccine is indicated in a post exposure setting (example, rabies or tetanus), it must take priority over the study vaccine and same rules will apply to subsequent study vaccinations
• Any history of HIV-related illness under Centers for Disease Control and Prevention (CDC) category C
• History of myocarditis, pericarditis, cardiomyopathy, congestive heart failure with permanent sequelae, clinically significant arrhythmia (including any arrhythmia requiring medication, treatment, or clinical follow-up)
• Chronic active hepatitis B or active hepatitis C (for example, positive serology with confirmatory positive polymerase chain reaction) or active syphilis infection. Active syphilis documented by examination or serology unless positive serology is due to past treated infection
• Receipt of blood products or immunoglobulin in the past 3 months
• History of anaphylaxis or other serious adverse reactions to vaccines or vaccine products, or neomycin or streptomycin or egg products
• History of chronic urticaria (recurrent hives)
• Chronic or recurrent use of medications which modify host immune response, example (e.g.) cancer chemotherapeutic agents, parenteral corticosteroids (short course oral steroids given for non-chronic conditions not expected to recur is not an exclusion criteria, topical steroid use is not an exclusion criteria), etc. but not including ART