Rationale: This trial tests a vaccine strategy with two candidates given in a sequence called a "prime-boost" strategy. The first vaccine in the series, ALVAC vCP1521, was designed to induce cytotoxic T-lymphocyte (CTL) responses. The second vaccine, AIDSVAX, combined synthetic fragments of HIV into a vector based on a disabled canarypox virus and was designed to induce an antibody response. The prime-boost combination was based on the rationale that the sequence of two different vaccines would lead to stronger and broader immune responses than multiple immunizations of the same vaccine. AIDSVAX has been tested on its own in two previous efficacy trials and was found to have no effect on rates of HIV infection. It had not been tested in combination.
Study Questions: This study was designed to test whether the prime-boost vaccine combination is safe and effective at reducing rates of HIV infection in men and women whose primary risk factor for HIV is sexual exposure.
Participants: 16,402 HIV-negative men and women
Country: Thailand
Trial sponsors and collaborators: Thai AIDS Vaccine Evaluation Group, Thailand Ministry of Public Health, US Military HIV Research Program
When can we expect results? Initial data show that vaccine recipients were 31% less likely than placebo recipients to become HIV-infected. There was no observed effect on viral load. Additional data analysis is ongoing.
To learn more visit: http://www.avac.org/ht/d/sp/i/3373/pid/3373
http://www.clinicaltrials.gov/ct/show/NCT00223080