July 19, 2010 - AIDS researchers have finally found a vaginal gel that halves a woman's risk of getting HIV from an infected sex partner.
The announcement, made at the outset of the 18th International AIDS Conference in Vienna, Austria, marks the beginning of the end of a 20-year search. Those years saw the failure of 11 clinical trials of six different agents intended to help women avoid HIV infection.
Now a vaginal gel containing tenofovir, an anti-HIV drug sold as Viread by Gilead Sciences Inc., is the first shown to protect against infection with the AIDS virus.
The announcement was made by husband/wife researchers Quarraisha Abdool Karim, PhD, and Salim S. Abdool Karim, MD, PHD, of the Center for the AIDS Program of Research in South Africa (CAPRISA) and Columbia University.
"We now have a product that can potentially alter the epidemic ... and save millions of lives by averting HIV infection," Quarraisha Abdool Karim said at a news teleconference.
She asked reporters to imagine a young woman in rural South Africa whose partner is a migrant worker who refuses to use a condom and will not allow her to use the female condom.
"Picture [that woman] asking what I have to offer to prevent her from getting infected with HIV," Abdool Karim said. "Until today I had nothing to offer. Today that changes. I can now offer tenofovir gel that offers 39% protection. And if she is highly adherent, it can be up to 54% protection."
That's far from full protection. But given that about 10% of the population in the area where the gel was tested are infected with HIV, such protection would have a profound effect.
"Without the gel, for every 100 women, 10 will be infected in a year. With this gel, only six women will be infected," Quarraisha Abdool Karim said. "For an individual woman, we say, 'If you use it consistently, you cut your chance of infection in half."
If one in three South African women at risk of infection use the gel, she estimated, over 20 years there would be 1.3 million fewer HIV infections -- and 820,000 lives would be saved.
The gel is applied 12 hours before sex and again 12 hours later. Salim Abdool Karim said that while this should be done only once every 24 hours, the gel should theoretically offer protection to women who have sex more than once during that time.
As welcome as the findings are, the study by the Abdool Karims and colleagues must be confirmed. The study gave the gel to 445 sexually active women in rural and urban South Africa, while 444 women received identical, inactive placebo gel.
Over the course of the study, 38 women who got the gel and 60 women who got the placebo became HIV infected. Overall, that's 39% effectiveness. But women who used the gel in at least 80% of sexual encounters had a 54% prevention rate.