Extended post-exposure protection against vaginal SHIV infection with tenofovir alafenamide fumarate/elvitegravir inserts in macaques.

Vaginal inserts that can be used on demand before or after sex may be a desirable HIV prevention option for women. We recently showed that inserts containing tenofovir alafenamide fumarate (TAF/20mg) and elvitegravir (EVG/16mg) were highly protective against repeated SHIV vaginal exposures when administered to macaques 4h before or after virus exposure (93% and 100%, respectively). Here, we show in the same macaque model that insert application 8h or 24h after exposure maintains high efficacy (94.4% and 77.2%, respectively). These data extend the protective window by TAF/EVG inserts and inform their clinical development for on-demand prophylaxis in women.