Awareness of ED-PrEP and interest in switching from daily oral PrEP to ED-PrEP in Brazil, Peru and Mexico ' the ImPrEP study


BACKGROUND: The WHO recommend Event Driven (ED)-PrEP for cisgender men who have sex with men (MSM) at risk for HIV and reporting infrequent sex. ImPrEP is a PrEP demonstration study conducted in Brazil, Peru and Mexico. We report results of a cross-sectional study to evaluate awareness of and interest in ED-PrEP among participants.
METHODS: Participants responded questions about sex frequency, current PrEP use and ED-PrEP (awareness/interest). Reasons for interest in switching from daily PrEP to ED-PrEP were assessed using a four-point Likert scale and responses were grouped as 'strongly agree/agree' vs. 'strongly disagree/disagree'. We used chi-square test to compare across countries.
RESULTS: From February/2020 to January/2021, 3,764 completed the questionnaire in Brazil (58.5%), Mexico (27.1%) and Peru (14.4%). The majority were MSM (97.6%) and median age was 31 years (IQR:26-37). Daily PrEP use as prescribed was reported by 96.9%. Sex < 2 days/week was reported by 23.4%. ED-PrEP awareness was higher in Mexico (36.3%) than in Brazil (30.2%) and Peru (27.8%) (p<.001). After a brief explanation, 22.1% reported interest in switching from daily PrEP to ED-PrEP, with higher rates in Mexico (26.9%) and Peru (26.0%) than in Brazil (18.8%) (p<.001). The main reasons for interest were: ED-PrEP is more convenient (85.4%), ability to postpone unplanned sex (80.8%) and capacity to predict sex (73.6%). For the 77.9% not interested, the main reasons were: comfort with daily PrEP (98.1%), ED-PrEP is a difficult regimen (92.7%) and feeling anxious about own HIV risk (90.8%). Inability to anticipate sex was higher in Mexico (93.1%) than Peru (89.6%) and Brazil (85.3%) (p<.001), while having concerns with ED-PrEP efficacy was less reported in Brazil (53.0%) than Peru (73.9%) and Mexico (75.7%) (p<.001). MSM reporting sex < 2 days/week were more interested in switching to ED-PrEP than those having sex '¥ 2 days/week (38.1% vs. 17.2%; p<.001).
CONCLUSIONS: Awareness and interest in switching to ED-PrEP was low among Latin-American MSM who use daily PrEP. However, those who reported infrequent sex showed interest and considered it a convenient regimen. Beliefs about low efficacy and anxiety about HIV infection risk suggest that knowledge dissemination is necessary to increase interest in ED-PrEP.