Microbicides raised hopes at the recent International AIDS Conference for their potential to offer an HIV prevention technique that could be initiated by women. But many researchers and advocates who work on microbicide development have been quick to offer cautions to the public that excitement not build too fast because a marketable product could still be years away.

The news that a Pennsylvania firm, Cellegy, has stopped its stage 3 (human testing) trial of a microbicide gel only adds to that sobering reminder. After a year of studying over 2,000 women in a trial that compared the real drug against a placebo, they have concluded that there is no statistically significant data being derived from the study. In an area where the rate of HIV transmission was expected to be about 3.7% a year, the women in this study are experiencing a rate of transmission closer to 2%. Good news, except it means that researchers can’t tell the difference between the microbicide’s effectiveness and the effectiveness of the condoms and HIV-prevention counseling offered to all of the women as part of the trial.

It’s the second stage 3 trial that has been cancelled for similar reasons, and it raises a rather difficult hurdle in the search for a viable microbicide product: there is not a good, ethical way to conduct a human trial of these drugs. If the women in the trial were not offered any counseling or condoms, it would be as if researchers are encouraging them to engage in dangerous sexual activity. If they use the condoms and are cautious about their sexual behaviors, there’s no way to know if the microbicides are working.

Aside from the need for another, as-yet-unknown form for such trials, this news reminds us of the need to continue pursuing gender equity and women’s rights, to engage men and boys in prevention, to pursue economic development, and to increase access to education for women and girls as means to prevent HIV infection. The hope of a technological solution cannot be supplemented for more systemic changes. If microbicides are to acheive the success that so many of us hope for–i.e., make a huge dent in the rate of HIV transmission–successes in these other areas in the meantime will only aid that achievement.