Feasibility of conducting HIV prevention trials among key populations in Nairobi, Kenya.

OBJECTIVE: To assess the feasibility of conducting HIV prevention trials among key populations in Nairobi, Kenya. BACKGROUND: HIV prevention trials require the inclusion of those at high risk of HIV infection and their informed decision to take part and remain in the clinical trial to the end is crucial. In Kenya key populations including men who have sex with men (MSM) and female sex workers (FSW) are, disproportionately, at high risk of HIV infection when compared to the general population. Few trials testing biomedical prevention products against HIV have enrolled Kenyan FSW and MSM. METHODS: We performed simulated vaccine efficacy trial (SiVET) using licensed hepatitis B vaccines as substitutes for a HIV vaccine candidate and included randomization for those immune to hep B. The SiVET was an observational study designed to mimic the rigors of a clinical trial; we assessed HIV risk, provided risk counselling and prevention tools and performed HIV testing at baseline and periodically until the end of the trial. MSM and FSW were enrolled at a ratio of 4:1. Volunteers were assigned to either hepatitis B vaccine or placebo. RESULTS: Recruitment took approximately 24 months between Sep 2015 and Sep 2017. Of the 368 volunteers screened, 250 (200 MSM and 50 FSW) were enrolled. Reasons for exclusion at screening included: being positive for HIV (n = 7), hepatitis (n = 14), other pre-existing medical conditions (n = 41), eligible but chose not to enrol (n = 47). Most of the volunteers adhered to study procedures and attended their study visits within the study window. These include volunteers who received the second vaccination 244 (98%), the third vaccination 228 (91%) and, the final study visit 217 (87%). The reasons volunteers discontinued from the study early included: relocation and loss to follow up (n = 14). A total of 8 cases of HIV infection were observed in 174.5 Person Years at Risk (PYAR), all among MSM, including 5 seroconversions identified at the last study visit, for a HIV incidence of 4.58 cases/ 100 PYAR, among MSM enrolled in the study. CONCLUSION: Our findings suggest that it is possible to conduct HIV prevention trials among key populations in Nairobi with a good adherence to a vaccine efficacy trial schedule. Despite HIV prevention efforts, we also noted a high incidence of HIV infection. This demonstrates the need for effective HIV prevention products in these populations.

Willingness to participate in future HIV vaccine trials among men who have sex with men and female sex workers living in Nairobi, Kenya.

OBJECTIVE: To evaluate factors associated with willingness to participate in future HIV vaccine trials among men who have sex with men and female sex workers living in Nairobi, Kenya. BACKGROUND: Working with 'key populations', those at elevated risk of HIV acquisition, is important to conduct efficient HIV prevention trials. In Nairobi Kenya, HIV infection is higher in men who have sex with men (MSM) and female sex workers (FSW) than in the general adult population, hence the need to establish if they would be willing to participate in future HIV vaccine trials. METHODS: We administered a structured questionnaire to MSM and FSW enrolled in a simulated vaccine efficacy trial (SiVET). The SiVET was an observational study designed to mimic the rigors of a clinical trial to assess HIV risk characteristics at baseline. After 12-15 months of follow-up, a structured questionnaire was administered to evaluate hypothetical willingness to participate in future HIV vaccine trials. RESULTS: Of 250 persons (80% MSM by design) enrolled in SiVET, 214 attended the final study visit and 174 (81%) of them expressed hypothetical willingness to participate in future HIV vaccine trials. These were 82% of MSM and 80% of FSW of those who attended the final study visit. Having a very good experience in the SiVET trial predicted willingness to participate in future HIV vaccine trials. Motivating factors for participation included a desire to receive education about HIV (59%) and to receive healthcare (57%). CONCLUSIONS: Our data demonstrate high willingness among key populations in Kenya, to participate in future HIV vaccine trials after completing participation in a SiVET. The findings suggest that these groups might be a reliable target population for consideration in future HIV vaccine trials. Assessment of willingness to participate in these populations provides important information that may help to inform future education and recruitment efforts for vaccine trials. Improving the research experience for members of key populations could impact their willingness to participate in HIV vaccine trials.