Study: Oral PrEP works as well in women with abnormal vaginal microbiota

Previous research suggested that an anti-HIV vaginal gel might not work as effectively in women with bacterial vaginosis and other imbalances in the vaginal microbiome, but a recent study presented by Renee Heffron of the University of Washington showed that daily oral pre-exposure prophylaxis (PrEP) works just as well on women with abnormal vaginal flora as on women with normal vaginal microbiota.

The study analyzed data from the Phase III Partners PrEP Study. That study instructed women to take an oral medication daily: either Truvada (tenofovir disoproxil fumarate/emtricitabine), Viread (tenofovir disoprixil fumarate), or a placebo. PrEP had over 70% efficacy.

Heffron's substudy of 1,470 women, of whom 24% had bacterial vaginosis at the beginning of the trial, 12% had intermediate microbiota, and 64% had normal microbiota, showed that PrEP had similar efficacy rates among all the groups. Among those with normal microbiota, the rate was 73%; among those with bacterial vaginosis it was 77%; and among those with intermediate microbiota it was 63%. The differences among these efficacy rates were not statistically significant and could have occurred due to chance.

“PrEP works in women when it is taken, including among those with abnormal microbiota. These data are reassuring that the delivery of oral PrEP to women does not need to be contingent upon testing for [bacterial vaginosis],” Heffron stated while presenting the results at the 2017 Conference on Retroviruses and Opportunistic Infections (CROI) in Seattle.