Important steps for PrEP uptake among adolescent men who have sex with men and transgender women in Brazil.

HIV Pre-exposure prophylaxis (PrEP) is an effective prevention tool, but there are still few studies about PrEP uptake among adolescents. We aimed to analyze the PrEP uptake process and factors associated with daily oral PrEP initiation among adolescent men who have sex with men (aMSM) and transgender women (aTGW) in Brazil. Baseline data from the first demonstration PrEP cohort study among aMSM and aTGW 15-19 years old (yo) ongoing in three large Brazilian cities (PrEP1519). After completing informed consent procedures, participants were enrolled in the cohort from February/2019 to February/2021. A socio-behavioral questionnaire was applied. Factors associated with PrEP initiation were assessed using a logistic regression model with adjusted prevalence ratios (aPR) and 95% confidence intervals (95%CI). Among recruited participants, 174 (19,2%) were aged 15-17 yo and 734 (80,8%) 18-19 yo. The rate of PrEP initiation was 78.2% and 77.4% for 15-17 yo and 18-19 yo, respectively. Factors associated with PrEP initiation were: black or mixed race (aPR 2.31; 95%CI: 1.10-4.84) among the younger adolescents 15-17 yo; experienced violence and/or discrimination due to their sexual orientation or gender identity (aPR 1.21; 95%CI: 1.01-1.46); transactional sex (aPR 1.32; 95%CI: 1.04-1.68); and having had between 2 to 5 sexual partners in the previous three months (aPR 1.39; 95%CI: 1.15-1.68) among those 18-19 yo. Unprotected receptive anal intercourse in the previous six months was associated with PrEP initiation in both age groups (aPR 1.98; 95%CI: 1.02-3.85 and aPR 1.45; 95%CI: 1.19-1.76 among 15-17 yo and 18-19 yo, respectively). The biggest challenge to promoting PrEP use for aMSM and aTGW was in the first steps of the PrEP uptake process. Once they were linked to the PrEP clinic, initiation rates were high.