One of the more promising approaches in the development of a preventive HIV vaccine uses a DNA plasmid to prime the immune response to an adenoviral vector boost. This primary purpose of this study is to evaluate the safety, tolerability, and immune response to recombinant adenoviral serotype 35 (rAd35) and serotype 5 (rAD5) HIV-1 vaccines in Ad-5 naive and Ad-5 exposed HIV-uninfected adults.~This study will last approximately 12 months. Participants will include those who are both rAD5-naive and rAD5-exposed and will be stratified into one of four groups. Each group will consist of two arms, one interventional and one control. Participants in Groups 1, 2, and 3 will be rAD5-naive. Participants in Group 4 will be rAD5-exposed.~Participants in Group 1 will receive an injection of rAD35 vaccine or placebo at study entry and an injection of rAD5 vaccine or placebo at Month 6 with nine follow-up visits through Month 12. Participants in Groups 2, 3, and 4 will injections of DNA vaccinations or placebo at study entry and at Months 1 and 2, and an injection of rAD35 vaccine, rAD5 vaccine, or placebo at Month 6 with twelve follow-up visits though Month 12. A physical, questionnaire, and counseling will occur at all visits. Blood and urine collection will occur at most visits. A rectal swab will occur at selected visits. For females, a pregnancy test will occur at all visits.~Participants will be contacted for safety follow-ups after the injection every year for 5 years. Health and adverse events will be recorded. Participants will not need to return to the study clinic unless HIV confirmatory testing is needed.
This study will evaluate the safety and preliminary immune response to recombinant adenoviral serotype 35 and 5 HIV-1 vaccines in HIV-uninfected adults.