Tailoring vaccine trial recruitment to individual communities

From the HVTN, Vaccine and Infectious Disease Division

Clinical trials for HIV vaccines are designed to test the safety and efficacy of potential prevention strategies, but biomedical research is only part of the study. 

In addition to scientists, successful HIV prevention trials rely on study participants representing the communities a vaccine would serve. To ensure that researchers and community members can respectfully and productively work together, a set of guidelines called Good Participatory Practices (GPP) describes the best practices for interactions between trial organizers and participants, but “there has not been any systematic analysis around the implementation of the GPP principles,” explained Gail Broder, the lead author on a recent publication in PLOS One. Broder, along with colleagues from the Vaccine and Infectious Disease Division’s HIV Vaccine Trials Network (HVTN) and the HIV Prevention Trials Network (HPTN) based at FHI360, developed a metric to evaluate one arm of GPP— the vaccine trial recruitment practices—to determine the most effective recruitment practices for engaging communities in different geographic regions.

During HIV prevention trials, community engagement begins the process of reaching potential study volunteers and moving them toward enrollment, and is an important element in the research. It establishes and preserves respect between researchers, participants, funding sponsors, and community stakeholders. Good community engagement also encourages future collaboration between the clinical trials and the communities, facilitating the design of HIV prevention methods that would ultimately serve those same people. Therefore, an essential component of community engagement is recruiting participants from high-risk regions and demographics into global HIV prevention trials. However, there is a need for standardized metrics to assess various strategies within specific geographic recruitment regions.

Broder and colleagues focused their analyses on two ongoing trials conducted jointly by the HVTN and HPTN, together known as the antibody-mediated protection (AMP) trials. These studies recruited participants from various countries around the world between 2017 and 2018. The authors wanted to measure how effectively the community engagement and recruitment methods described by GPP brought in study participants to be screened for eligibility, and how many ultimately enrolled. At the outset of the trial, the HVTN/HPTN Network Community Engagement Program—permanent teams that support the community engagement efforts at local trial sites—worked with leaders from each participating community to select recruitment methods considered most likely to be effective in that region. The strategies ranged from internet advertisements, print flyers, face-to-face outreach, referral by other participants or partners, and were tailored to each region’s community.

During the enrollment period, the AMP trials’ site staff conducted screening activities with potential study participants. The researchers asked the recruited participants how they had become aware of the AMP trials. Additionally, the study calculated the screening:enrollment ratio, a metric to determine what percentage of screened individuals ultimately enrolled in the trials. A lower screening:enrollment ratio demonstrates higher enrollment among screened participants, suggesting efficient use of screening time and resources.

Community engagement framework from the HVTN/HPTN.
Community engagement framework from the HVTN/HPTN. Figure from publication.

Using this data, Broder and colleagues found that the most successful recruitment practices varied between regions. In the region comprised of Brazil, Peru, Switzerland, and the United States, participants were most often recruited through the internet and face-to-face outreach, while the African clinic sites in Botswana, Kenya, Malawi, Mozambique, South Africa, Tanzania, and Zimbabwe were most often recruited by face-to-face outreach or referral by another participant. However, referrals were the most efficient recruitment method globally, with the lowest screening:recruitment ratios across regions.

These findings suggest that input from local community leaders, who share values, norms, and culture of potential participants, is key for designing effective region-specific HIV prevention trials recruitment strategies. The study also emphasized that the most effective recruitment strategies meet participants in their communities and disseminate information through a medium already familiar in the region. Additionally, no one strategy recruited a majority of participants, demonstrating that a broad range of recruitment strategies is necessary to reach the desired study populations. Broder said that these findings demonstrate that “there are in fact regional differences” in the most effective HIV prevention trial recruitment strategies, and that researchers “can’t assume anything about how strategies that work in one place will work in another.” Going forward, HIV prevention trial recruitment practices can be tailored to each specific community by engaging with communities and asking “the communities to tell us what recruitment measurements we should be using, and continuing to measure these efforts so that changes or trends can be identified,” said Broder.

Broder GB, Lucas JP, Davis J, Wallace SE, Luthuli N, Baepanye K, White RR, Bolton M, Blanchette C, Andrasik MP. 2020. Standardized metrics can reveal region-specific opportunities in community engagement to aid recruitment in HIV prevention trials. PLoS One. 15(9): e0239276. 2020 Sep 17;15(9):e0239276. doi: 10.1371/journal.pone.0239276. eCollection 2020.