Composition of the Vaginal Microbiome May Alter PrEP's Efficacy

Efficacy data on preexposure prophylaxis (PrEP) in women have been inconsistent. Although adherence is a major determinant of PrEP's effectiveness, little is known about biological factors that may exert influence. Vaginal microbiomes fall into two groups: Lactobacillus -dominant (LD; >90% Lactobacillus species) and non- Lactobacillus -dominant (non-LD; <30% Lactobacillus species; abundant Gardnerella vaginalis and other bacteria). Bacterial vaginosis, which results when the vaginal microflora shifts from LD to non-LD, has been associated …