Motivators of enrolment in HIV vaccine trials: a review of HIV vaccine preparedness studies

HIV vaccine preparedness studies (VPS) are important precursors to HIV vaccine trials. As well, they contribute to an understanding of motivators and barriers for participation in hypothetical HIV vaccine trials. Motivators can take the form of altruism and a desire for social benefits. Perceived personal benefits, including psychological, personal, and financial well-being, may also motivate participation. The authors performed a systematic review of HIV VPS using the Cochrane Database for Systematic Reviews, Medline, PubMed, Embase, and Google Scholar. The authors independently searched the literature for individual HIV VPS that examined motivators of participation in a hypothetical HIV vaccine trial, using the same search strategy. As the denominators employed in the literature varied across studies, the denominators were standardized to the number of respondents per survey item, regardless of their willingness to participate (WTP) in an HIV vaccine trial. The authors retrieved eight studies on social benefits (i.e., altruism) and 11 studies on personal benefits conducted in the Organization for Economic Co-operation and Development (OECD) countries, as well as 19 studies on social benefits and 20 studies on personal benefits in the non-OECD countries. Various different forms of altruism were found to be the major motivators for participation in an HIV vaccine trial in both the OECD and the non-OECD countries. In a large number of studies, protection from HIV was cited as a personal motivator for participation in a hypothetical HIV vaccine trial in the OECD and the non-OECD countries. Knowledge of motivators can inform and target recruitment for HIV vaccine trials, although it must be remembered that hypothetical motivators may not always translate into motivators in an actual vaccine trial.