The CAPRISA 004 study has reported in the journal Science that an antiretroviral microbicide applied regularly as a vaginal gel reduced incidence of HIV by 39% (up to 54% in women with high adherence) when compared to a group using a placebo gel.
From the abstract in Science:
HIV incidence in the tenofovir gel arm was 5.6 per 100 women-years, i.e., person time of study observation (38/680.6 women-years), compared to 9.1 per 100 women-years (60/660.7 women-years) in the placebo gel arm (incidence rate ratio = 0.61; P = 0.017). In high adherers (gel adherence >80%), HIV incidence was 54% lower (P = 0.025) in the tenofovir gel arm. In intermediate adherers (gel adherence 50 to 80%) and low adherers (gel adherence <50%), the HIV incidence reduction was 38% and 28%, respectively. Tenofovir gel reduced HIV acquisition by an estimated 39% overall and by 54% in women with high gel adherence. No increase in the overall adverse event rates was observed. There were no changes in viral load and no tenofovir resistance in HIV seroconverters. Tenofovir gel could potentially fill an important HIV prevention gap, especially for women unable to successfully negotiate mutual monogamy or condom use.
The gel is produced by Gilead Sciences Inc (Foster City, CA) and is applied 12 hours before and after sex. The most expensive component of the system is the 32 cent plastic applicator, though this may be because the Tenofovir used in the gel was donated by Gilead.
Full article in Science: Effectiveness and Safety of Tenofovir Gel, an Antiretroviral Microbicide, for the Prevention of HIV Infection in Women…
CAPRISA 004 press release (.pdf)…
CAPRISA – Centre for the AIDS Programme of Research in South Africa….