Jo-Ann Passmore co-authors Science paper on effects of tenofovir gel microbicide

In a recent paper published in Science, Associate Professor Jo-Ann Passmore (Member of the IDM) and colleagues report on their investigations into whether vaginal microbiota modulated tenofovir gel microbicide efficacy. This was within the CAPRISA (Centre for the AIDS Program of Research in South Africa) 004 trial.

Antiretroviral-based strategies for HIV prevention have shown inconsistent results in women. Their study provides evidence linking vaginal bacteria to microbicide efficacy through tenofovir depletion via bacterial metabolism.

Two major vaginal bacterial community types - one dominated by Lactobacillus (59.2%) and the other where Gardnerella vaginalis predominated with other anaerobic bacteria (40.8%) - were identified in 688 women profiled. Tenofovir reduced HIV incidence by 61% in Lactobacillus-dominant women but very significantly less so in women with non-Lactobacillus bacteria. Detectible mucosal tenofovir was lower in non-Lactobacillus women, negatively correlating with G. vaginalis and other anaerobic bacteria, which depleted tenofovir by metabolism more rapidly than target cells convert to pharmacologically active drug.

Klatt N.R. et al. Vaginal bacteria modify HIV tenofovir microbicide efficacy in African women. Science (2017) 356(6341):938-945