New Gel Treatment May Cut HIV Transmission Risk

Researchers say that they are approaching a possible day when a gel could help prevent HIV transmission through anal sex. The downside: people don't like using it, HealthDay reported on Feb. 28.

The article noted that study subjects used a gel form of tenofovir, which has been shown to cut the risk of virus transmission when used vaginally. Participants in the study used the gel rectally prior to anal sex, but were not exposed to the virus, the article said.

But the participants did not like using the gel, the article noted, and some suffered side effects. In general, the study indicated that the public might one day use a tenofovir gel preparation, or something similar to it.

"These are early results, but [they] help set the stage for current and future trials of rectal microbicides and the development of a rectal-specific formulation of tenofovir gel," the University of Pittsburgh's Dr. Ian McGowan said in a media release issued by the Microbicide Trials Network.

The article noted that anal sex might carry a higher risk of HIV infection than vaginal sex--another question that would need to be addressed in efforts to develop and market a gel for men who have sex with men (MSMs).

Rather than study participants using the gel and then actually having sex with HIV-positive partners, the study involved participants using the gel on a daily basis. The 18 study participants did not have sex during the research period, the article said. Cells were then harvested from each participant's rectum and subjected to HIV in laboratory conditions. Cells from individuals who had used the gel for a week were more resistant to the virus, researchers found.

The study also involved a tenofovir pill that was administered orally, and an inactive gel that served as a placebo.

"Most researchers believe the rectum is more difficult to protect from HIV than the vagina, so these findings demonstrating that it can be done will energize the search for a safe, effective and user-friendly rectal microbicide," commented the Foundation for AIDS Research's Rowena Johnston. "These researchers have recognized that products like condoms or microbicides are only effective if people use them. Their plan to make what appears to be an effective product into a formulation people will want to use could be a winning combination."

A study last year found that tenofovir gel could help protect women who engaged in vaginal sex if used up to 12 hours, or even if applied after vaginal sexual contact. The study was seen as significant because almost half of all people living with HIV are women. In some cultures--and in some domestic situations--women have less control over the question of whether they are able to use safer sex practices, an article posted at EDGE on July 29, 2010, noted.