This study, published in the journal Science, provides evidence linking vaginal bacteria to microbicide efficacy through tenofovir depletion via bacterial metabolism.

The results of The Ring Study, a randomized controlled trial that evaluated the safety and efficacy of extended use of a vaginal ring containing dapivirine for the prevention of HIV infection among women in South Africa and Uganda,were published December 1, 2016, in The New England Journal of Medicine. The authors concluded that the dapivirine ring was not associated with any safety concerns and was associated with a rate of acquisition of HIV-1 infection that was lower than the rate with placebo.

Tenofovir vaginal gel was not effective in preventing HIV among a large, diverse population of young South African women, reports this press release from the Follow-on African Consortium for Tenofovir Studies. Less than a quarter of the participants were able to use the gel consistently. The press release discusses the results presented at the 2015 Conference on Retroviruses and Opportunistic Infections and their implications.