July 8, 2008

HIV Gels May Help Men More Than Women

Gels that have been developed to protect women from the AIDS virus may be just as likely to protect men from catching the disease as well, researchers said on Monday.

That prediction would rely on the event of such gels and creams being perfected to be effective for men.

Sally Blower of the University of California, Los Angeles, and David Wilson of the University of New South Wales in Sydney, Australia said women who use gels of microbicides could end up with fewer treatment options if they do become infected with HIV.

"Paradoxically, although microbicides will be used by women to protect themselves against infection, they could provide greater benefit to men," they wrote in the Proceedings of the National Academy of Sciences.

Microbicides have been developed to be applied vaginally or rectally to protect against sexual transmission of HIV. Currently, none are on the market, but many are in the process of being tested.

Blower and Wilson wanted to see if women risked developing resistance to such drugs if they used a microbicide but got infected anyway.

Using computer models based on data collected from ongoing trials of microbicides, researchers confirmed their presumption that the drugs can be absorbed into the body through the vaginal wall and then, like any other drug, could cause the AIDS virus to mutate.

"What we found out that was interesting or surprising or paradoxical, was that under some conditions males would actually benefit a lot more than females," Blower said.

"You would actually prevent a lot more infections in men than in women. That was surprising."

If a microbicide was not proven to be 100 percent effective, or if women did not use it consistently, a certain percentage of women would become infected. In fact, some of the women would continue to use the microbicide, and would develop resistance.

Since drug-resistant HIV is less likely to be transmitted from person to person, Blower said male sex partners of drug-resistant women could be protected from the incurable virus.

"At the moment, there is absolutely nothing that women can do to protect themselves from HIV -- condoms are not in women's control," Blower said.

An estimated 33 million people have HIV, mostly in Africa. More than 61 percent of Africans with HIV are women who were infected by their husbands or other male sexual partners.


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University of California, Los Angeles

University of New South Wales

Proceedings of the National Academy of Sciences