Count in the young people : HIV vaccine trial participation in Tanzania

Background: For nearly four decades, HIV infection has raged across the world; leaving devastation in its wake particularly in sub-Saharan Africa. Even though the use of antiretroviral (ARV) drugs has significantly contributed to lessening HIV/AIDS related morbidity and mortality, their efficacy has had a limited outcome on the cure and prevention of both old and new HIV infections. Like many viral diseases, an effective HIV vaccine is considered the cornerstone for ending the HIV epidemic. The involvement of young people in preventive HIV vaccine clinical trials is fundamental as they are unduly affected by the HIV burden. Whilst new vaccine models continue to be tested for safety, immunogenicity and efficacy, only a few young people join such innovative clinical interventions; highlighting an evolving need for understanding the intricacies of partaking in clinical HIV vaccine trials.

Aim: The overall aim for this thesis was to increase knowledge of factors contributing to recruitment and participation of young people in preventive HIV vaccine trials.

Methods: The thesis encompassed four studies using both qualitative and quantitative methods. Data collection for cross sectional study I was done among 450 youth using questionnaires to assess factors contributing to their willingness to participate in an HIV vaccine trial. Study II used seven focus group discussions to elicit the influence and opinions of members of the community on participation in the trial. In study III, we employed respondent-driven sampling to enlist 600 young female sex workers in a cross-sectional study that assessed willingness to participate in HIV efficacy trials and risk behaviors using questionnaires. In-depth interviews were used in study IV to explore experiences of participating in HIV vaccine trials among 17 young volunteers in a phase I/II HIV vaccine trial, TaMoVac 01.

Results: This thesis identified positive and negative attributes of the willingness of young people to participate in an HIV vaccine trial at several levels of ecological model. At the intrapersonal level, altruism, self-independence in decision making, being in charge of safe sex, having some knowledge of HIV vaccines and regular health check-ups were regarded as positive attributes for joining the trial whereas anxiety about fertility and HIV positivity post vaccination were identified constraints. Looking at the interpersonal level, endorsement of the trial by significant others and support of staff were features of partaking whereas fears of perceived contents of HIV vaccine and mischaracterization of sexual practices were portrayed as impediments. Last but not least, support of regulatory institutions, members of parliament, stigma, and the trial center were elements at the community/institutional level, while substance abuse, unemployment and poverty were structural factors hampering the contribution of young people to HIV vaccine trials.

Conclusion: Youth showed readiness to participate in phase IIa HIV vaccine trial. For most young people, the decision to participate in vaccine trials largely depend on support of members of the community. In contrast, for high-risk young women, this decision largely be their own. Some factors like altruism, support from members of the community and, perceived personal benefit served as positive attributes to participation. Despite such readiness, fertility issues, stigma, poverty were perceived as hurdles needed to be resolved by different stakeholders on individual, community and societal levels for successful participation.

List of scientific papers

I. Mbunda T, Bakari M, Tarimo EAM, Sandström E, Kulane A. Factors that influence the willingness of young adults in Dar es Salaam, Tanzania, to participate in phase I/II HIV vaccine trials. Glob Health Action. 2014; 7: 22853.
https://doi.org/10.3402/gha.v7.22853

II. Mbunda T, Tarimo EAM, Chalamilla G, Bakari M, Sandström E, Kulane A. (2016). The Influence of Community Members on Participation by Youth in an HIV Vaccine Trial in Tanzania. PLoS ONE. 11(12): e0168660.
https://doi.org/10.1371/journal.pone.0168660

III. Mbunda T, Tarimo EAM, Bakari M, Sandström E, Kulane A. Recruitment using Respondent Driven Sampling, risk behaviors assessment and willingness of young Female Sex Workers in Dar es Salaam, Tanzania to participate in HIV vaccine trials. [Submitted]

IV. Mbunda T, Tarimo EAM, Bakari M, Sandström E, Kulane A. Why I am a part of an endeavor to save mankind - Perspectives of young volunteers on participation in an HIV vaccine trial: A qualitative study from Dar es Salaam, Tanzania. [Submitted]