Vaginal Gel Can Reduce HIV Risk in Women, Researchers Report in Science

Estimated HIV/AIDS prevalence among young adults (15-49) by country as of 2008, based on data from UNAIDS 2008 global report.

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A vaginal gel containing the HIV drug tenofovir has shown promise as a safe and effective method for reducing HIV infection in women, according to a study conducted in South Africa. The study was published Monday 19 July at the Science Express website.

HIV prevention options for women are urgently needed, especially in sub-Saharan Africa where young women bear the greatest burden of the HIV epidemic.

In this region, approaches to HIV prevention such as abstinence, monogamy, and condom use is “very difficult for young women, so our existing tools don’t address the South African epidemic,” said author Salim Abdool Karim of the Centre for the AIDS Program of Research in South Africa (CAPRISA) at the University of KwaZulu-Natal in Durban, South Africa, and the Mailman School of Public Health at Columbia University.

In a teleconference for journalists, co-lead author Quarraisha Abdool Karim, who is also at CAPRISA and Columbia University, elaborated on this point, asking listeners to imagine a typical scenario:

“A young woman in a rural community in South Africa walks through many clinic doors but particularly mine over the past 20 years. [She is] coming in and asking me, what do I have to offer her to protect her from getting infected? Her partner is a migrant worker. He refuses to use a condom. She’s not sure about his faithfulness in the relationship. And she cannot use a female condom either in this relationship. And until today, I’ve not been able to say, ‘This is what I have to offer you.’ Today that changes.”

The Abdool Karims and their colleagues now report results from the CAPRISA 004 Randomized Control Trial, a nearly three-year trial conducted in urban and rural South African women, which tested the gel’s efficacy at preventing HIV infection. The trial was a double-blind, randomized control trial, in which about 445 women received the tenofovir gel and 444 received a placebo gel.

The tenofovir gel reduced HIV infection by 39% overall and by 54% in women who used the gel most consistently, compared to the women who used the placebo, the researchers report.

The women in the trial were tested for HIV at monthly follow-up visits, at which they also received reproductive health services, such as pregnancy tests, and HIV prevention services, including HIV pre- and post-test counseling, HIV risk-reduction counseling, condoms, and treatment for other sexually transmitted diseases.

In their article, the authors point out several issues that will need further research, including the need to enhance and objectively measure how closely women follow the instructions about using the gel, since about 40% of the women in the trial had below 50% adherence. Furthermore, the gel’s effectiveness appeared to decline after 18 months, and the reasons for this trend, including the possibility of declining adherence over time, need further investigation.

Kathy Wren

20 July 2010