The gel, which is applied by a woman before and after sex, cuts the risk of acquiring HIV, the virus responsible for AIDS, by 39 percent.
It can also cut the chance of getting genital herpes by 51 percent.
The gel is important to developing nations suffering from an AIDS pandemic, such as South Africa, Swaziland and Botswana. In those countries, more than 1 in 5 adults have contracted the virus, the vast majority of them women.
The gel represents the first working HIV-prevention method that is controlled entirely by women, reports the Wall Street Journal.
In fact, about one third of women in the $18 million study said their partners didn't know they were using the gel.
The clear, odorless gel contains the antiretroviral drug tenofovir, manufactured free by California-based Gilead Sciences (In the U.S., it's on the market as Viread.) Normally it's consumed in pills, but the gel -- which is applied on the skin -- contains a smaller dose, and thus milder side effects.
The study was randomized, double-blind and placebo-controlled to ensure accurate results. It was conducted by Quarraisha and Salim Abdool Karim at the Centre for the AIDS Programme of Research in South Africa.
The results are even more significant because the virus that causes herpes, HSV2, also makes women more susceptible to HIV.
Researchers say the gel could prevent 500,000 infections over the next 10 years in South Africa alone.
A few more points about the gel from the Journal report:
- The study followed 889 women at an urban and rural site for between one and two and a half years.
- 60 out of 444 women using the placebo gel contracted HIV.
- 38 out of 445 women on the tenofovir gel contracted HIV. That's an improvement of 39 percent.
- There was a wide margin of error in the results, owing to a medium-sized pool of subjects.
- With consideration to the margin of error, the gel could be as effective as 60 percent -- or as ineffective as 6 percent.
A larger trial for the gel, using 5,000 women, is already underway across several African nations. It is set to end in 2013.
Major funding for the study was provided by the U.S. Agency for International Development.
Illustration: Henrik Jonsson/iStockPhoto
This post was originally published on Smartplanet.com