Last year a study reported that a vaginal gel containing 1% tenofovir (an anti-HIV drug) was partially effective in preventing HIV infection in at-risk women in Africa (see this blog Sept. 5, 2010). Researchers were particularly interested in developing a gel against HIV because it would be a prevention method controlled by women, rather than by men. The study was hailed by a breakthrough by AIDS researchers, and several large follow-up studies were undertaken to to confirm the findings.
The results have been very disappointing. One of the follow-up trials was halted recently when it became clear that the vaginal gel was not going to be effective in reducing the rate of HIV infection in what was thought to be a similar group of at-risk women. (See also the PBS report.) Researchers are scratching their heads and trying to work out the differences between this and the previous study to see if they offer any clues as to why the recent trial failed. In the meantime, another study is still ongoing.
But let's put the disappointment in perspective. This is the scientific process at work. Hypotheses are made and tested, findings repeated and confirmed (or not confirmed), hypotheses modified and tested again….its a continuous process that brings us closer to the truth through repeated success and failure, trial and error. We’ll just have to wait for the next instalment in this ongoing saga. In the meantime, don’t expect a vaginal gel against HIV infection to hit the market any time soon.