Safety of an HIV Vaccine (AVX101) in HIV Uninfected Volunteers in the United States and South Africa

This study was designed to evaluate the safety and immunogenicity of an alphavirus replicon HIV subtype C gag vaccine. This vaccine utilizes a propagation-defective replicon vector system derived from an attenuated strain of Venezuelan Equine Encephalitis (VEE) virus. The vaccine replicon expresses the gag gene from a South African subtype C isolate of HIV-1. This study evaluated the AVX101 vaccine in healthy, HIV uninfected volunteers in both the United States and South Africa. Participants will be randomized to receive either vaccine or placebo at study entry and again at Months 1 and 3. The study was originally designed to enroll four groups of participants in both the US and South Africa, with successive groups receiving increasing doses of the vaccine, but was later amended to enroll only two groups. Twelve US participants (US Group 1) were randomized to receive either vaccine or placebo. After a review of initial safety data from this group, 12 South African participants (SA Group 1) were randomized to receive the same vaccine dose as US Group 1 or placebo, while 12 US participants (US Group 2) were randomized to receive the next higher vaccine dose or placebo. Review of safety data from SA Group 1 and US Group 2 was used to inform the decision to begin enrollment into SA Group 2 . Participants had nine study visits over 12 months. Study visits included clinical evaluation, urine and blood tests, and HIV tests. After each injection, participants were asked to record their temperature and any symptoms each day for 7 days and report them to the clinic staff.