Background: South African adolescents are at risk for HIV acquisition. PrEP is licensed and being offered to key populations, but not yet to adolescents. This open-label 12-month PrEP study examined uptake, safety and adherence to PrEP and assessed sexual risk behaviour among adolescents in Soweto and Cape Town, South Africa
Methods: Sexually active, healthy, HIV negative, adolescents (15-19 years) participated in a study of Tenofovir/Emtricitabine PrEP. Participants were asked to take daily PrEP for at least 3 months, were seen monthly, after which they could opt-out of PrEP if preferred. At subsequent 3-monthly follow-up visits, participants could decide to stay on or off PrEP per preference. Laboratory and clinical safety monitoring occurred at each visit, including HIV and pregnancy testing. Plasma and dried blood spots (DBS) were serially collected for tenofovir (TFV) and tenofovir diphosphate (TFV-DP) levels at every PrEP refill visit. Plasma TFV levels were offered at each visit as part of adherence counselling.
Results: 244 individuals were screened and 148 were enrolled (median age 18,67%F). 3(1%) had undiagnosed HIV infection and 9 (6%) were pregnant at screening. STI diagnosis at baseline was high (40%) and remained high throughout. 26 (18%) participants opted out of PrEP at 12 weeks. Thereafter PrEP opt-out (and opt-in) at months 6 and 9 included 41% and 43% (5% and 7%) of the cohort respectively. PrEP was safe and reasonably well tolerated. Plasma TFV levels were detectable in 57% of participants at week 12, 38% at week 24 and 38% at study end. One HIV seroconversion occurred on study (0.76/100 person-years) in a 19 year old woman who had stopped PrEP 24 weeks prior to diagnosis
Conclusions: Pluspills enrolled a cohort of self-selected adolescents at high risk of HIV acquisition and offered an opportunity to engage on ethical norms for adolescent research. PrEP was safe and tolerable in those who persisted. However PrEP usage decreased and adherence diminished over time, when visits became less frequent. STI diagnoses remained constant and HIV incidence was low. SA adolescents need access to PrEP with tailored adherence support and potentially augmented visit schedules.