Adolescent and adult participation in an HIV vaccine trial preparedness cohort in South Africa.

Purpose: The importance of involving adolescents in HIV prevention trials has been recognized, but there have been few experiences reported from sub-Saharan Africa. We analyzed adult and adolescent data from a cohort study conducted to assess the feasibility of involving adolescents and adults in HIV vaccine-related studies.

Methods: Two hundred HIV-negative participants aged 16 to 40 years were enrolled, including 86 (43%) adolescents. At baseline, sexual risk behavior and willingness to participate (WTP) in future HIV vaccine trials questionnaires were administered. Three monthly HIV counseling, pregnancy, HIV and syphilis tests were performed. Risk questionnaires were repeated at 6 months and WTP at 12 months.

Results: No significant difference in retention between adults (83%) and adolescents (87%) was noted (p = .58). Initially, more adults (40%) reported WTP compared to adolescents (13%) (p < .001). At the end of the study both groups reported higher levels of WTP; increasing to 40% among adolescents. HIV incidence during the study was 9.2 infections per 100 person-years (95% confidence interval [CI]: 4.4-19.2) among adolescents compared to 5.8 (95% CI 2.6-12.9) in adults (p = .42).

Conclusions: Retention of high-risk HIV-negative adolescents in a cohort study is feasible. Following education, adolescents reported improved WTP. The high HIV incidence rate in adolescents highlights the importance of including this group in prevention trials.