Abstract:
Background: Volunteers in phase I/II HIV vaccine trials are assumed to be at low risk of acquiring HIV infection and are
expected to have normal lives in the community. However, during participation in the trials, volunteers may encounter
social harm and changes in their sexual behaviours. The current study aimed to study persistence of social harm and
changes in sexual practices over time among phase I/II HIV vaccine immunogenicity (HIVIS03) trial volunteers in Dar es
Salaam, Tanzania.
Methods and Results: A descriptive prospective cohort study was conducted among 33 out of 60 volunteers of HIVIS03 trial
in Dar es Salaam, Tanzania, who had received three HIV-1 DNA injections boosted with two HIV-1 MVA doses. A structured
interview was administered to collect data. Analysis was carried out using SPSS and McNemars’ chi-square (x2) was used to
test the association within-subjects. Participants reported experiencing negative comments from their colleagues about the
trial; but such comments were less severe during the second follow up visits (x2 = 8.72; P,0.001). Most of the comments
were associated with discrimination (x2 = 26.72; P,0.001), stigma (x2 = 6.06; P,0.05), and mistrust towards the HIV vaccine
trial (x2 = 4.9; P,0.05). Having a regular sexual partner other than spouse or cohabitant declined over the two follow-up
periods (x2 = 4.45; P,0.05).
Conclusion: Participants in the phase I/II HIV vaccine trial were likely to face negative comments from relatives and
colleagues after the end of the trial, but those comments decreased over time. In this study, the inherent sexual practice of
having extra sexual partners other than spouse declined over time. Therefore, prolonged counselling and support appears
important to minimize risky sexual behaviour among volunteers after participation in HIV Vaccine trials.
