Factors associated with vaccination completion and retention among HIV negative female sex workers enrolled in a simulated vaccine efficacy trial in Kampala, Uganda.
Mayanja, Yunia;
Abaasa, Andrew;
Namale, Gertrude;
Asiki, Gershim;
Price, Matthew A;
Kamali, Anatoli;
(2019)
Factors associated with vaccination completion and retention among HIV negative female sex workers enrolled in a simulated vaccine efficacy trial in Kampala, Uganda.
BMC Infectious Diseases, 19 (1).
725-.
ISSN 1471-2334
DOI: https://doi.org/10.1186/s12879-019-4328-1
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BACKGROUND: Female sex workers (FSWs) at substantial risk of HIV are potentially a suitable group for HIV prevention trials including vaccine trials. Few HIV vaccine preparatory studies have been conducted among FSWs in Sub-Saharan Africa (SSA); data are therefore limited on acceptability of vaccine trial procedures. We determined vaccination completion and one-year retention among FSWs in Kampala, Uganda. METHODS: We conducted a prospective study that simulated a vaccine efficacy trial among HIV negative FSWs (18-49 years). Hepatitis B vaccine (Engerix B) was used to mimic an HIV vaccine product. Volunteers received 1 ml intramuscular injection at 0, 1 and 6 months, and made additional visits (3 days post-vaccination and months 3, 9 and 12). They were censored at that visit if diagnosed as HIV positive or pregnant. We collected socio-demographic, behavioral and clinical data at baseline, 6 and 12 months and fitted Poisson regression models with robust standard error to find factors associated with vaccination completion and retention. RESULTS: We enrolled 290 volunteers (median age 27 years) of whom 230 reached a study end-point as follows: 7 became HIV infected, 11 became pregnant and 212 completed both the vaccination schedule and 12-month visit giving a retention of 77.9% (212/272). Vaccination completion was 82.4%. Non-retention at 1 year was more likely among those reporting symptoms of genital ulcer disease (GUD) in the past 3 months (IRR 1.90; 95% CI 1.09-3.32) and those < 35 years; (IRR 6.59; 95% CI 2.11-20.57). Non-completion of the vaccination schedule was associated with being < 35 years (IRR 13.10; 95% CI 1.89-90.92, reporting GUD symptoms (IRR 3.02; 95% CI 1.71-5.33) and reporting consistent condom use with new sexual partners (IRR 2.57; 95% CI 1.10-6.07). CONCLUSIONS: FSWs are at substantial risk of HIV infection and yet willing to participate in HIV vaccine and prevention research; young FSWs should be empowered, and those reporting GUD symptoms need close follow up to improve participation in future HIV vaccine trials.