Behavioral and Structural Interventions for PrEP Adherence Among Young Female Sex Workers from Western Kenya

HIV incidence is high among young female sex workers (YFSW) in Kenya. Pre-exposure prophylaxis (PrEP) for HIV prevention is recommended for at-risk populations, but its effectiveness requires consistent access and adherence. The IPrEP study compared the feasibility, acceptability, and effectiveness of two adherence support interventions on PrEP adherence among YFSW in Kisumu, Kenya. Study follow-up coincided with national restrictions on travel and gatherings due to the COVID-19 pandemic. We conducted an unblinded, randomized-controlled trial enrolling 18-24 year-old HIV-negative YFSW with no current or recent PrEP use (NCT03988387, registered: June 17, 2019). Participants were initiated on oral PrEP and randomized to either peer-delivered adherence support (PS), or SMS reminders and resource transfer (RRT) to support adherence for 12 months. PrEP was provided without these interventions for an additional 12 months to assess the durability of their effect. Intention-to-treat analysis of effectiveness was conducted at 12, 18, and 24 months using plasma tenofovir levels and self-report. Of the 289 YFSW screened, 200 were enrolled (100 per arm). Median age was 22 years, 46% reported condom use at last sex, and 26 male clients averaged in the past month. At 12, 18, and 24 months, detectable levels of tenofovir in plasma were 3%, 1%, and 0% in the PS arm and 9%, 9%, and 1% in the RRT arm (p-value = 0.4). Perfect 7-day adherence was self-reported by 85%, 81% and 83%, and 86%, 87% and 76% in the PS and RRT arms at 12, 18 and 24 months, respectively. Two seroconversions occurred during follow-up: one at 12 months and one at 18 months of follow-up. In this population of YFSW, no difference in tenofovir levels by arm was noted. The very low levels of tenofovir in the plasma, in contrast to high self-reported adherence, may be due in part to perceived lower HIV risk resulting from decreased frequency of sex work during the COVID-19 period. Findings highlight the urgent need for long-acting PrEP for this population.