Science Spotlight

Increased racial and ethnic minority participation in HIV vaccine trials

From the HIV Vaccine Trials Network, Vaccine and Infectious Disease Division

In the United States, racial and ethnic minorities bear disproportionate burdens of infectious diseases. For example, the Centers for Disease Control and Prevention reports that in 2016 non-Hispanic African Americans and Hispanic Americans accounted for 70% of new HIV infections in the US. However, minority participation within clinical trials, including HIV vaccine trials, is severely lacking. Without accurate representation of the populations that bear the highest burden of HIV infection, clinical trials conducted among non-representative populations are not generalizable to those outside of the enrollment groups. This limits the relevance of trial results when applied to the more diverse greater population of the US, as physiological and biological differences between populations may affect the vaccine efficacy. Furthermore, African Americans and Latino/a Americans currently face systemic barriers to HIV prevention and care, and their inclusion in early stage preventive vaccine trials, as well as increased inclusion of other minority populations, increases access to prevention interventions, risk-reduction counseling, and care for HIV-positive individuals. In order to quantify the disparity between HIV incidence and trial enrollment among racial minorities, the HIV Vaccine Trials Network (HVTN) based at Fred Hutch previously published a study (Djomand, et al)1 that profiled the race and ethnicity of HIV vaccine trial participants between 1988 and 2002 and found minorities to be woefully underrepresented in clinical trials. To follow up on these statistics, Katie Huamani, a UW graduate student receiving mentorship and supervision from Michele Andrasik (HVTN) and Barb Metch (Statistical Center for HIV/AIDS Research and Prevention) and additional support from Gail Broder (HVTN), sought to characterize the participants between 2002 and 2016 and published her findings in Public Health Reports.

To provide an updated analysis of minority enrollment in HIV clinical trials, the authors consulted the HVTN case report forms from the trials that occurred in the US between May 2002 and June 2016 and recorded participants’ demographic data. The current study included 43 HIV vaccine trials that spanned 18 research sites within 14 cities, prompting the authors to assign each study to one of four geographical regions (as outlined by the US Census Bureau) in order to compare each region’s HIV infection rates, specified by the National HIV Surveillance System, to respective enrollment rates. The authors compiled self-reported race identification of each participant, which was recorded as American Indian/Alaskan Native, Asian, black or African American, Native Hawaiian/other Pacific Islander, White (Hispanic/Latino or non-Hispanic/Latino), or other. To maintain consistency with the previous study and CDC data, the authors combined race and ethnicity, counting Hispanic/Latino as its own minority category. Additionally, Asian and Native Hawaiian/Pacific Islander were combined as were other and multiracial groups. Of the 3469 participants included in the analysis, 67% identified as non-Hispanic/Latino White, 17.3% as non-Hispanic/Latino Black or African American, 3.2% as Asian or Native Hawaiian/Pacific Islander, 0.3% as American Indian/Alaska Native, and 4.3% as multiracial or other. Compared to the Djomand study that characterized enrollment between 1988 and 2002, the proportion of participants who identified as racial minorities increased from 1.67% to 32.8%. However, unlike the Djomand study, the authors found no upward (or downward) trend in minority enrollment between 2002 and 2016.

Racial and ethnic distribution of Phase 1 and Phase 2a HIV vaccine participants in the United States from 1988-2002 (left) and racial and ethnic distribution between 2002 and 2016 (right).  There was a two-fold increase in the proportion of racial and ethnic minorities enrolled in Phase 1 and Phase 2a trials from 17% between 1988-2002 to 33% between 2002 and 2016.  The increase in the proportion of Black participants is significant at p<.0001 and the increase in the proportion of Hispanic/Latino participants is significant at p<.0001
Racial and ethnic distribution of Phase 1 and Phase 2a HIV vaccine participants in the United States from 1988-2002 (a) and racial and ethnic distribution between 2002 and 2016 (b). Figure provided by Michele Andrasik.

Although the overall trajectories of minority inclusion in HIV clinical trials are promising, this study highlights the massive disparity that remains between which populations have elevated risk of acquisition of HIV and which populations are included in HIV preventive vaccine trials. Between 2002 and 2016, around three-quarters of all new HIV infections in the US occurred in racial/ethnic minorities, mostly non-Hispanic Black and African Americans, representing one to three times the proportion of these groups enrolled in HIV trials. Likewise, Hispanic/Latino persons carry an HIV infection burden one to almost seven times that of the percentage of Hispanic/Latino participants in vaccine trials. “We are making significant improvements in engaging, recruiting and retaining racial and ethnic minority participants.  Despite our progress, we still have a long way to go, especially with our efforts in the South, which has the highest rates of new HIV infections in the United States,” Andrasik explained. Broder further summarized why minority participation is crucial for development of an effective vaccine: “If we hope to have a vaccine against HIV that can be licensed for use in all people, then we have to do the work to test it in all people. The communities have to be engaged now, during the research process, so that one day they will be willing to get the licensed vaccine. They will understand the safety, they will know that people like themselves were involved and part of the process. That’s a vastly different message than the kinds of experiences that communities of color have had in medical research in the past. I’m proud to contribute to changing the conversation.”

Importantly, this study reinforced the need for the HVTN to continue to identify innovative strategies to “prioritize partnerships with and leverage expert feedback from racial/ethnic minority communities and community-based organizations throughout the research process," Andrasik said. Additionally, the HVTN has focused on increasing diversity among staff members and the provision of staff cultural responsiveness training. “In the future, we hope to explore how having multiple devalued identities (intersectionality) such as race, ethnicity, sexual orientation and gender identify increases vulnerability to HIV infection and creates barriers to engagement, recruitment and retention in preventive HIV vaccine trials,” Andrasik said.

1 Djomand et al 2005

This work was supported by the National Institute of Allergy and Infectious Diseases HIV Vaccine Trials Network, the Eunice Kennedy Shriver National Institute of Child Health and Human Development, and the University of Washington Center for Studies in Demography & Ecology

Huamani KF, Metch B, Broder G, Andrasik M. 2018. A demographic analysis of racial/ethnic minority enrollment into HVTN preventive early phase IV vaccine clinical trials conducted in the United States, 2002-2016. Public Health Reports. 134(1):72-80. doi: 10.1177/0033354918814260. Epub 2018 Dec 5.