Background: HIV remains a major public health problem in Sub-Saharan Africa. About 54.5% of all people living with HIV live in Eastern and Southern Africa. There is no HIV vaccine or cure available yet despite ongoing research to develop one and uptake of vaccines is critical in the global society. It is imperative to describe the perceptions and experiences of the vaccines trial participants, as they may give lessons for COVID-19 vaccine development. Methods: A phenomenological qualitative study was conducted to describe the experiences of volunteers who participated in HIV vaccine trial in Tanzania. A purposive sample of 20 of the 60 trial participants was interviewed. Interviews were subjected to thematic-content analysis. Results: The study showed that trial participation was driven by positive expectations related to health and the realization of the need for an effective vaccine to combat HIV. However fear and concerns about the safety of the trial vaccine were the frequently reported challenges to participation. The significant others and community play an important role in trial participation. Conclusions: The success of a trial depends on direct and indirect participation in trials. Future vaccine trials must promote positive expectations for trial participation and address fears and concerns related to vaccine safety.

Keywords: HIV Vaccine trial, Participant experiences, COVID-19 vaccine trial; trial benefits and challenges; Tanzania