Mount Sinai School of Medicine researchers demonstrated that a gel applied in the vagina provides protection from both the human immunodeficiency virus (HIV) and the herpes simplex virus. The study, presented at the 12th Conference on Retroviruses and Opportunistic Infections, is the first to show that a gel can retain anti-viral activity within the human vagina.

The study, which was funded by the National Institutes of Health (NIH), investigated the efficacy of PRO 2000, a topical microbicide under development by Indevus Pharmaceuticals, Inc.

"There is an urgent need for the development of safe and effective vaginal microbicides," Marla Keller, assistant professor of Medicine at the Mount Sinai School of Medicine and the researcher who presented the data said adding, "While condoms offer protection against sexually transmitted infections, their effectiveness is limited because they require partner initiation or consent."

According to the United Nations' 2004 report on the global AIDS epidemic, an estimated 40 million people worldwide are living with HIV, and women account for nearly half of those infected. As stated by the World Health Organization, unprotected sex is the predominant mode of HIV transmission, and genital herpes plays a major role in the sexual spread of HIV.

The researchers conducted a prospective, randomized, double blind, placebo-controlled study among 20 HIV-infected women to assess the antiviral activity of PRO 2000 in cervicovaginal lavage (CVL) fluid collected before and one hour after administration of a single intravaginal dose of PRO 2000 gel or a matched placebo gel. CVL specimens were tested for their ability to prevent HIV and HSV infection of susceptible human cells in culture. Levels of inflammatory cytokines were also measured as markers of acute inflammation.

Analyses showed that CVL obtained after the application of PRO 2000 gel reduced both HIV and HSV infectivity by at least 1000-fold compared to CVL obtained at baseline. The effects were highly statistically significant. In contrast, CVL collected from placebo gel recipients showed little or no anti-viral effect. Furthermore, the researchers found similar low levels of inflammatory cytokines in CVL collected from the drug and placebo groups, indicating that PRO 2000 application did not induce an acute inflammatory response, the release stated.