April 13, 2021, 1:46 p.m. News Staff — A review of more than 200 clinical vaccine trials has found that compared with U.S. census data, members of racial and ethnic minority groups and older adults are often underrepresented while white individuals and women are often overrepresented. The review also found that more than 40% of trials did not provide data on participant race and nearly 60% did not report data on participant ethnicity. The findings, presented in a recent edition of JAMA Network Open, indicate that considerable challenges exist in resolving inequities in clinical trial research, and suggest that more work needs to be done to ensure the inclusion of minority populations in vaccine trials.
“This collaborative work highlights a problem that’s plagued the scientific community for too long — inadequate representation in clinical trials,” Steven Pergam, M.D., the study’s corresponding author and an associate professor in the Vaccine and Infectious Disease Division at Fred Hutchison Cancer Research Center in Seattle, told the University of Nebraska Medical Center Newsroom. “The diversity seen in COVID-19 vaccine trials demonstrates we can do this, but we need to assure future studies focus not just on rapid enrollment, but also inclusion.”
In the review, performed by a research team from five states and Puerto Rico, the investigators analyzed data from completed interventional human vaccine trials that were registered and reported on the ClinicalTrials.gov database between July 1, 2011, and June 30, 2020. All the trials were conducted in the United States and addressed either vaccine immunogenicity or efficacy of preventive vaccines. The analysis excluded trials that were based outside the United States, had unknown status or were completed but did not have results reported.
The investigators collected a variety of demographic data, including sex, age and race/ethnicity. For race/ethnicity, the researchers used the categories used on ClinicalTrials.gov as determined by the Office of Management and Budget Standards for the Classification of Federal Data on Race and Ethnicity. Population data from the 2011 and 2018 American Community Surveys were used to compare demographic data.
Overall, 230 vaccine trials met the researchers’ inclusion criteria, with a total of 219,555 participants.
While all the included trials provided data on participant age and sex, only 134 trials (58.3%) reported data on race and just 79 (34.3%) reported data on ethnicity.
When compared with U.S. census data, among 91 vaccine trials that included adults and reported data on race, white participants were slightly overrepresented, while Black/African American, American Indian/Alaska native and multiracial participants were slightly underrepresented. In trials that included adults and reported data on ethnicity, Hispanic or Latino participants were underrepresented by between 5.1% and 6.9%.
In pediatric vaccine trials, white, Black/African American, multiracial and Hispanic or Latino participants were underrepresented, while Asian, American Indian/Alaska native and Hawaiian/Pacific islander participants were overrepresented.
In vaccine trials that reported data on sex, on average female participants were overrepresented by between 4.5% and 5.2% compared with the general population. This overrepresentation remained even when trials that targeted exclusively female individuals were excluded, leading the investigators to suggest conducting further research.
Finally, among adult vaccine trials that reported age as a percentage, just over 12% of participants were 65 years or older, whereas in 2018, an estimated 16% of the U.S. population was in this age group.
The researchers expressed surprise over the number of trials that lacked data on race and ethnicity, given that the National Institutes of Health Revitalization Act of 1993 mandated the inclusion of women and minorities in all NIH-funded clinical research, and that in 2014, the FDA published an action plan designed to improve the completeness and quality of data collection, reporting and analysis of demographic subgroups in clinical trials.
The authors stated that the missing data “may be important in the context of understanding health disparities, such as social determinants of health (e.g., socioeconomic barriers), implicit bias and an increased burden of comorbidities.”
“These findings, combined with studies that document lower vaccination rates and increased disease burdens in some of these populations, demonstrate the need to improve minority group enrollment in clinical trials,” they added.
The authors also explained how increasing minority participation in vaccine trials could address related issues about immunizations.
“Improving racial/ethnic diversity in clinical trials is important because enrollment may be associated with vaccination rates in minority groups,” they wrote. “Efforts to improve inclusion may help to address vaccine hesitancy, provide education and counter safety concerns about vaccines by ensuring equitable representation in definitive clinical trials.”
“Enhancing enrollment may also address these issues by ensuring early community engagement,” they continued. “In addition, improving the diversity of the health care and clinical trial workforces may further engender trust, ensure culturally appropriate education, and limit language barriers to enhance trial participation and vaccination rates within minority communities.”
Gretchen LaSalle, a 2020 AAFP Vaccine Science Fellow, associate clinical professor at the Washington State University Elson S. Floyd College of Medicine, Spokane, and a practicing family physician at MultiCare Rockwood Clinic (also in Spokane), told AAFP News that family physicians have a vital role to play in addressing the concerns of patients who may be vaccine hesitant.
“It is important for us to know, and to be able to relay to our patients, what is demonstrated in this study: that efforts are ongoing to ensure increasing representation for people of color and older adults in vaccine trials. Indeed, these are the groups that are being hardest hit by the SARS-CoV-2 pandemic,” LaSalle said. “It is extremely important to building vaccine confidence that these patients can now look to the COVID-19 vaccine trials and see that people just like them were included and that the vaccines were shown to be safe and effective across demographics.”
LaSalle said that getting patients from racial and ethnic minorities to be vaccinated and to participate in vaccine trials can be boiled down to one issue — trust — and that FPs are ideally positioned in that regard.
“As family physicians, we have the privilege of developing years-long relationships with our patients,” said LaSalle. “Our minority patients may have lost confidence in the pharmaceutical industry or in the government, but if we’ve earned their trust, they will know that we have their best interest at heart.”
Earning that trust, LaSalle explained, may require FPs and patients to work together to overcome prior negative experiences.
“First, I think we need to respect the foundation of mistrust caused by the abuse and neglect of Black and Indigenous populations and other people of color that has gone on for centuries in the halls of science and medicine,” LaSalle said. “We also need to acknowledge that significant inequities in the care of people of color still exist today. And we must commit ourselves, in every interaction and with every individual, to the inclusion, fairness, equity and respect that all people deserve.”
When talking with patients who are vaccine hesitant, LaSalle recommended that family physicians take the following steps:
Finally, LaSalle noted that the AAFP and other organizations have produced a wealth of resources to address vaccine hesitancy and to help end racial and ethnic disparities in health care. She recommended that members visit the Academy’s Center for Diversity and Health Equity, and that they also review recently published statements on systemic racism and health disparities and helping Black patients overcome hesitancy about COVID-19 vaccines.
The Academy has published additional resources on this and related topics. In 2018, the AAFP approved a policy on collecting racial, ethnic, sexual orientation and gender identity data in surveys conducted by agencies such as the CDC and other governmental public health organizations. More recently, the Academy has posted new content on the association between chronic health conditions and severe illness resulting from influenza and the risks of influenza in racial and ethnic minorities on its patient-centric site, familydoctor.org.