Evaluating the Safety and Immunogenicity of a Prime-boost Vaccine Regimen of GEO-D02 DNA and MVA/HIV62B With and Without B63521^11 gp120 and IHV01 gp120 Env Proteins in Healthy, HIV-uninfected Adult Participants

The purpose of this study is to evaluate the safety and immunogenicity of a prime-boost vaccine regimen of GEO-D02 DNA and MVA/HIV62B with and without B63521\^11 gp120 and IHV01 gp120 Env proteins in healthy, HIV-uninfected adult participants.

This study will evaluate the safety and immunogenicity of a prime-boost vaccine regimen of GEO-D02 DNA and MVA/HIV62B with and without B63521\^11 gp120 and IHV01 gp120 Env proteins in healthy, HIV-uninfected adult participants. Participants will be randomly assigned to one of five groups. Participants in all five groups will receive GEO-D02 DNA by intramuscular (IM) injection at Months 0 and 2. Then, at Months 4, 6, and 10, participants will receive three additional injections according to their assigned group: * Group 1: MVA/HIV62B, placebo for B63521\^11 gp120, and placebo for IHV01, all by IM injection * Group 2: MVA/HIV62B by IM injection and placebo for B63521\^11 gp120 and for IHV01, both by subcutaneous (SC) injection * Group 3: MVA/HIV62B, B63521\^11 gp120, and IHV01, all by IM injection * Group 4: MVA/HIV62B, placebo for B63521\^11 gp120, and IHV01, all by IM injection * Group 5: MVA/HIV62B by IM injection and IHV01 and B63521\^11 gp120, both by SC injection Participants will attend several study visits through Month 16. Visits may include physical examinations, blood and urine collection, electrocardiogram, HIV testing, risk reduction counseling, and questionnaires. Study staff will contact participants at Month 24 for follow-up health monitoring.