Feasibility of Identifying a Female Sex Worker Cohort at High Risk of HIV Infection in the Caribbean for HIV Vaccine Efficacy Trials: Longitudinal Results of HVTN 907.

backgroundIdentifying cohorts of Caribbean women with HIV infection rates sufficient for inclusion in HIV vaccine efficacy trials has been challenging. HVTN 907 determined the feasibility of identifying and retaining a cohort of women at high risk for HIV acquisition by focusing recruitment on female sex workers (FSWs).

methodsHIV uninfected FSWs, residing in Haiti, Dominican Republic, and Puerto Rico, who reported unprotected sex and met previously described more stringent site-specific eligibility criteria, were eligible. Behavioral risk assessment, HIV counseling and testing, and pregnancy testing were performed at baseline, 6, 12, and 18 months.

resultsAmong 799 FSWs (264 from Dominican Republic, 334 from Haiti, and 201 from Puerto Rico), the median age was 26 years, with 54% having less than a high school education and 45% having a monthly household income of less than $US 100. Median number of male partners 6 months before screening was 200. Retention at 18 months was 93%. Twelve women became HIV infected, 9 from Haiti. The annualized HIV incidence was 1.07% (95% confidence interval: 0.55% to 1.87%). Pregnancy incidence was 22.5% (95% confidence interval: 21.9% to 29.5%). Statistically significant declines in risk behaviors occurred between screening and the 18-month visit assessment. DISCUSSION: The HVTN 907 study identified a high-risk cohort of women with excellent retention for all 3 sites, despite major challenges especially in Haiti. These results show that a bridging study of a vaccine shown to be efficacious in other clade settings would be possible among FSWs in the region, particularly in Haiti.