Abstract

Background: Research to discover an effective and safe vaccine is crucial to decrease HIV burden. However, it is paramount to understand social-behavioral aspects, such as underlying perceptions about HIV, misconceptions about HIV vaccine research and its volunteers, and the effects of experimental vaccines on trial participants, that can impede trial conduct and eventual vaccine uptake. Methods: This research project is divided into 2 studies conducted in Maputo, Mozambique, using both quantitative and qualitative methods and the health belief model. As part of a 2-year follow-up incidence study, a willingness to participate questionnaire was administered to a cohort of 577 HIV-negative young adult participants, at screening and at the exit visit (study I). Research subjects who participated in a phase II HIV vaccine preventative clinical trial, answered to the same semi-structured questionnaire (31 participants) before and after unblinding (1-year interval) and participated in 12 in-depth interviews and 3 focus group discussion (study II). Results: A total of 577 participants were screened, including 275 (48%) women. At screening 529 (92%) expressed willingness to participate and the proportion remained stable at 378 (88%) of the 430 participants retained through the exit visit (p=0.209). Helping the country (n=556) and fear of needles (n=26) were the top motive and barrier for willingness to participate, respectively. The health belief model was used to explain the decision-making progress to participate in a HIV vaccine study. HIV susceptibility, infection severity and benefits of participating in a HIV vaccine trial must outweigh barriers for trial participation in order to promote the switch from intention to action (actual participation in HIV vaccine trials). Participants also suffered negative social harm driven mainly by HIV stigma from family and peers regarding their participation in HIV vaccine trials. Conclusion: The present research reports a continuous high intention to participate in HIV vaccine trial among young adults in Maputo city and identified the factors associated with it. It also describes how actual participants of a phase II HIV clinical trial reason their participation and the factors associated with their retention participation in the HIV vaccine trial.