Prevention Now Central to AIDS Fight
International Focus Is on Ways to Prevent New HIV Infections
Aug. 18, 2006 (Toronto) -- HIV preventive methods such as microbicides and circumcisioncircumcision took center stage this week as more than 27,000 doctors, researchers, activists, and HIV-positive people descended upon this Canadian metropolis for the world's largest AIDS gathering.
Also grabbing headlines were novel drugs to overcome the virus that has eluded defeat since the first reports a quarter century ago of what would come to be called acquired immune deficiency syndrome.
As in years past, politics were intertwined with science, with experts calling for more accountability and funding from world leaders -- a must, they say, to turn the tide in the epidemic that has claimed more than 25 million lives.
But it was prevention that was foremost in many people's minds.
The tone was perhaps set when Microsoft founder Bill Gates kicked off the XVI International AIDS Conference here with pleas for rapid development of microbicides and other methods to give women the means to prevent new HIV infections.
"We're really putting prevention on the map like we haven't before," says Helene Gayle, MD, co-chair of the conference and CEO of CARE, the international poverty-fighting organization.
"Very soon, we could have new, highly effective ways to prevent many of the four million new HIV infections that occur each year," she tells WebMD.
HIV in Women
With women now accounting for over half of the 34 million adults infected with HIV worldwide, methods they can use without their partners knowing are key to prevention efforts, experts say.
Microbicides -- gels, foams, or creams applied to the vagina or rectum -- are one promising approach. They can combat HIV on a variety of fronts: disabling the virus, interfering with the process by which the virus enters and takes hold in cells, and strengthening the body's defenses against infection.
As of mid-2006, there were more than 25 products in various stages of development, with five in late-stage studies on effectiveness. Results could be available by late 2007, says Gita Ramjee, PhD, of the HIV Prevention Research Unit of the South Africa Medical Research Unit.
Compelling evidence from monkey studies suggests they will work, with two of the leading candidates preventing infection in all animals exposed to the virus, she tells WebMD.
Even if it's not 100% effective in humans, a little benefit can go a long way, she says. One recent study suggests a microbicide that lowers the risk of infection by 40% -- and is used by 30% of at-risk women in developing nations -- could prevent more than 2 million infections a year.
The first-generation microbicides furthest along in development have to be used right before sex. But researchers are already developing second-generation microbicides, using more potent antiviral drugs, that could be taken hours, even days, in advance.