This study will evaluate the safety and immune response of the combination of two vaccines: a multigene DNA HIV-1 vaccine that also expresses GM-CSF (GEO-D03) and a MVA HIV-1 (MVA/HIV62B) vaccine. HIV-1-infected young adults who have suppressed viral levels, have likely acquired (Clade B) HIV-1 infection from sexual contact, and are on highly active antiretroviral therapy (HAART) will be randomly assigned to one of two study arms. Arm A participants will receive the GEO-D03 vaccine at entry and Week 8 and the MVA/HIV62B vaccine at Weeks 16 and 24. Arm B participants will receive placebo vaccines at entry and at Weeks 8, 16, and 24.~Study duration will be 120 weeks (24 weeks for vaccinations plus 96 weeks of follow-up). Study participants will remain on HAART throughout the study. Study visits will occur at screening, entry, and at Weeks 1, 8, 9, 16, 17, 24, 25, 36, 48, 72, 96, and 120. At each study visit, participants will undergo blood collection, a physical exam, and an adherence assessment. At screening, participants will also undergo an electrocardiogram (ECG) and urine collection. Some blood samples will be stored for future use.
The purpose of this study is to evaluate the safety of two HIV vaccines in HIV-1-infected young adults who are taking anti-HIV medications and have very low virus levels. This study will also look at how the immune system responds to the vaccines.