An ongoing dialogue on HIV/AIDS, infectious diseases,
September 24th, 2009
HIV Vaccine Study Shows Promise …
So says this press release by the US Military HIV Research Program:
A Phase III clinical trial involving more than 16,000 adult volunteers in Thailand has demonstrated that an investigational HIV vaccine regimen was safe and modestly effective in preventing HIV infection. According to final results released by the trial sponsor, the U.S. Army Surgeon General, the prime boost combination of ALVAC® HIV and AIDSVAX® B/E lowered the rate of HIV infection by 31.2% compared with placebo … In the final analysis, 74 placebo recipients became infected with HIV compared to 51 in the vaccine regimen arm. The efficacy result is statistically significant. The vaccine regimen had no effect on the amount of virus in the blood of volunteers who became HIV-infected during the study.
This is great news, of course; we’ve become so used to hearing gloom and doom about HIV vaccine studies that one can’t help but be excited, despite the relatively low (but statistically significant) rate of protection.
Still, one suspects such a combination vaccine could be logistically difficult to manufacture and administer , especially since one arm of the strategy employs the live-canarypox virus ALVAC vector, and 5 injections were required.
Plus there is the issue of cross-clade protection — the vaccine was designed to protect against the most common strains circulating in Thailand (B and E). While B is quite common in North America and Western Europe, is is far less so in Sub-Saharan Africa, where the HIV epidemic is the most severe.
Nonetheless, if you put this news along with the proven protective effects of male circumcision and HIV treatment — the latter I believe to be greatly underestimated by the medical and non-medical community — things are definitely looking up in the HIV prevention arena.
Further details on the study will be presented at the AIDS Vaccine Conference, October 19-22 in Paris — interestingly a return to the same city where HIV was discovered.