Science doi:10.1126/science.1193748 (2010)

After 15 years of failed attempts to develop an effective anti-HIV vaginal gel, a clinical trial has shown that one containing an antiretroviral drug can cut HIV infection in women by more than 50% if used consistently.

Quarraisha Abdool Karim at the Centre for the AIDS Program of Research in South Africa, in Durban, and her colleagues tested the 1% vaginal gel formulation of the drug tenofovir. The 2.5-year study involved 889 South African women aged between 18 and 40 years who were HIV negative, sexually active and at high risk of HIV infection.

Compared with women who used a placebo, the tenofovir gel reduced HIV infection in the group by 39% overall, and by 54% in women who used the gel most consistently before and after sex.