Vaginal gel shows promise in AIDS prevention

Montreal, February 9: A vaginal gel which can kill the HIV virus, was hailed for holding hope as a weapon in the arsenal against the deadly disease.

According to clinical trials conducted in Africa and the United States, the US National Institutes of Health said an experimental vaginal gel has yielded promising results in preventing HIV infection in women.

Although the microbicide PRO 2000 made by Lexington, Massachusetts-based Indevus Pharmaceuticals, Inc., proved safe and 30 percent effective, protection is far from complete. The gel cuts HIV risk by 30- 36 percent, if women who went off the gel during a pregnancy are excluded.

Anthony S Fauci, Director of the National Institute of Allergy and Infectious Diseases (NIAID) said, "Although more data are needed to conclusively determine whether PRO 2000 protects women from HIV infection, the results of this study are encouraging.”

Salim S. Abdool Karim, director of South Africa's AIDS research center along with his colleagues conducted the trails in the US and six African cities. They enrolled more than 3,000 sexually active women. All participants received detailed information about the possible risks and benefits of the trial before enrollment. They were monitored monthly during the course of the study, which averaged 20 months. In addition, all the women were counseled on safe sex practices, given condoms, and tested and treated for sexually transmitted infections.

In the test, women were divided into four groups. One group was given the PRO 2000 gel and condoms, to be used as the women saw fit. The second group received a fake gel and condoms, and a third group received just condoms. A fourth group received a second substance being tested called BufferGel.

In the final analysis, 194 women in the study became infected with HIV. Of these infections, 36 occurred in the PRO 2000 group, 54 in the BufferGel group, 51 in the placebo group and 53 in those who did not use gel. Based on these results, PRO 2000 was 30 percent effective, while BufferGel had no preventive effect on HIV infection. Both PRO 2000 and BufferGel were found to be safe.

Karim stated that "The study, while not conclusive, provides a glimmer of hope to millions of women at risk for HIV, especially young women in Africa. It provides the first signal that a microbicide gel may be able to protect women from HIV infection."

Women make up 50 percent of all HIV-infected people worldwide and nearly 60 percent in sub-Saharan Africa. In several southern African countries young women are at least three times more likely to be HIV-positive than young men. In most cases, women become infected with HIV through sexual intercourse with an infected male partner. An effective microbicide could provide women with an HIV prevention method they initiate.

Karim reported the findings at the annual Conference on Retroviruses and Opportunistic Infections in Montreal.