Both Daily and On-Demand PrEP Are Effective Against HIV, French Study Confirms
A large, eight-year French study presented at the Conference on Retroviruses and Opportunistic Infections (CROI 2026) in Denver, US, has confirmed the efficacy and safety of both daily and on-demand oral pre-exposure prophylaxis (PrEP) for HIV prevention. The study, known as Prévenir, enrolled over 3,200 participants, primarily gay or bisexual cisgender men, in the Paris region.
Study Design and Key Findings
The Prévenir Study allowed participants to choose between taking PrEP daily or using an event-driven, “on-demand” approach with tenofovir disoproxil/emtricitabine. Researchers found a remarkable consistency in usage patterns, with approximately half of participants consistently opting for daily PrEP and half for on-demand PrEP throughout the study duration. However, individual choices shifted over time, with 59% of those starting on daily PrEP switching to on-demand PrEP at least once, and 52% switching back.
Over the course of the study, only 14 participants acquired HIV, resulting in a very low overall annual HIV incidence rate of 0.11%. Whereas HIV incidence was twice as high among those primarily using on-demand PrEP, this difference was not statistically significant due to the small number of HIV acquisitions.
Population-Level Impact and Disparities
The study aimed to contribute to a 15% reduction in HIV cases in the Paris region compared to pre-study levels. While this target was not fully achieved, with a population-level incidence reduction of only 2%, the study revealed important disparities. HIV cases fell by 33% among French-born participants, but increased by 75% among those born abroad. This highlights the necessitate for targeted PrEP implementation strategies for specific populations.
Participant Demographics
The study population was overwhelmingly comprised of gay or bisexual men, with approximately 99% identifying as such. The majority of participants (85%) were White, with an average age of 36.
Implications for PrEP Access and Implementation
Professor Jean-Michel Molina, a lead researcher on the study, emphasized that both daily and on-demand PrEP were safe and effective within the study population. However, he underscored the importance of addressing disparities in PrEP access and implementation, particularly among men and transgender women born abroad and other at-risk groups. Read the full study report on aidsmap.
About the Prévenir Study
The ANRS Prévenir cohort study began in May 2017 in the Île-de-France region of France, aiming to prevent recent HIV infections through PrEP. The study administered a fixed-dose combination of tenofovir disoproxil and emtricitabine (245 mg and 200 mg, respectively) and was conducted by a team led by Professor Jean-Michel Molina in partnership with the AIDES association. Learn more about the ANRS Prévenir cohort.