HIV-1 risk and vaccine acceptability in the Ugandan military

Between July and October 1993, 570 19- to 22-year-old volunteers were screened for HIV-1, with a resulting seroprevalence rate of 18.3% (95% CI: 14.0%, 22.6%). A cohort of 249 HIV-1-noninfected military recruits in the Ugandan Peoples' Defense Forces was followed prospectively for up to 18 months to document rates of HIV-1 seroprevalence, seroconversion, and knowledge and attitudes related to vaccine acceptability. The HIV-1 seroincidence rate was 3.56 per 100 person-years (95% CI: 1.49, 5.62) over 309 person-years of observation. At the 3- and 12-month visits, subjects were interviewed on issues of acceptance and knowledge about vaccines, including anti-HIV vaccines in particular. More than 90% believe that HIV vaccines will not cause HIV infection, and if offered, 88% report that they would take the vaccine if they were not already infected. Nonvaccine prevention methods were considered less reliable; monogamy and condom use were considered effective by only 33.5% and 69.3% of the cohort respectively. After completing the vaccine acceptability questionnaire at the 12-month visit, subjects were offered an approved polyvalent meningococcal vaccine as an indicator of general vaccine acceptance. All subjects reported receiving at least one previous vaccination, and 95% willingly accepted the meningococcal vaccination. The Ugandan military is a stable population at substantial risk for HIV-1 infection and may be a suitable population for vaccine efficacy trials.