Event driven or daily PrEP: ANRS Prévenir study confirms that these two biomedical prevention strategies are very effective and safe

23 July 2019 – The ANRS Prévenir study offers prevention based on daily or event-driven (also called on-demand) PrEP (preexposure prophylaxis) to seronegative volunteers at high risk of HIV infection in and around Paris, France. ANRS Prévenir reached its recruitment target of 3000 participants 2 years after its May 2017 inception. Data analysis from June 2019 confirmed the effectiveness of PrEP, with only two cases of HIV infection in participants who had discontinued PrEP several weeks before. These results are presented today by Jean-Michel Molina (Hôpital Saint-Louis, AP-HP and Université de Paris) at the 10th IAS Conference on HIV Science (Mexico City, 21-24 July 2019).

Event-driven PrEP uses a short 4 pill dosing strategy before and after a sex event as an alternative to routinely taking a daily pill to achieve protection against sexual exposure to HIV. The so-called “2+1+1” approach involves a double dose of 2 pills taken between two and 24 hours before sex, then, a third pill 24 hours after the first two pills, and a fourth pill 48 hours after the first two pills.

Dr Rachel Baggaley, WHO Coordinator for Key Populations and Innovative HIV Prevention said, “WHO is pleased to see these exciting results. Building on this evidence we are releasing a new technical brief to provide guidance to countries on an event-driven PrEP option for men who have sex with men, allowing people greater choice, flexibility and convenience for HIV prevention.”