Disclosures: Andrasik reports receiving a grant from the NIH. Del Rio reports receiving financial support from the National Institute of Allergy and Infectious Diseases and NIH. Silver reports receiving funding from the Arnold P. Gold Foundation and the Binational Scientific Foundation outside the submitted work. Please see the study for all other authors’ relevant financial disclosures.
February 20, 2021
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Some racial, ethnic groups underrepresented in US-based vaccine trials

Disclosures: Andrasik reports receiving a grant from the NIH. Del Rio reports receiving financial support from the National Institute of Allergy and Infectious Diseases and NIH. Silver reports receiving funding from the Arnold P. Gold Foundation and the Binational Scientific Foundation outside the submitted work. Please see the study for all other authors’ relevant financial disclosures.
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An assessment of U.S.-based clinical trials for vaccines revealed that certain racial or ethnic groups were underrepresented in both adult and pediatric studies, whereas women were overrepresented, researchers reported in JAMA Network Open.

Underrepresented groups included Black or African American, American Indian or Alaska Native, and Hispanic or Latino individuals, and older adults.

Clinical trial
An assessment of U.S.-based vaccine clinical trials revealed that women are overrepresented, whereas racial/ethnic minorities are underrepresented in both adult and pediatric studies.
Credit: Adobe Stock

Laura E. Flores, BA, a PhD candidate at the University of Nebraska Medical Center, and colleagues performed a cross-sectional study examining data from completed U.S.-based vaccine trials registered on ClinicalTrials.gov from July 1, 2011, through June 30, 2020. They included 230 U.S.-based trials representing all phases with 219,555 participants 78.3% were randomized trials, and 69.1% were for viral vaccinations.

“The goal was to provide history and context for the current disparities in COVID-19 impacting the United States and to inform future trials,” Flores told Healio.

According to the study, females accounted for 56% of participants in adult vaccine trials — disproving the researchers’ hypothesis that they would be underrepresented. Among trials reporting age as a percentage, participants aged 65 years or older represented just 12.1% of the population (95% CI, 12%-12.3%).

Laura E. Flores
Julie K. Silver

They study demonstrated that white individuals were overrepresented (77.9%; 95% CI, 77.4%-78.4%), whereas Black or African American individuals (10.6%; 95% CI, 10.2%-11%) and American Indian or Alaska Native individuals (0.4%; 95% CI, 0.3%-0.5%) were underrepresented compared with U.S. census data. Enrollment of Asian individuals was similar to census data (5.7%; 95% CI, 5.5%-6%), whereas enrollment of Hispanic or Latino individuals (11.6%; 95% CI, 11.1%-12%) was also low, even among the limited number of adult trials reporting ethnicity, Flores and colleagues said.

They found disparities among pediatric trials as well. According to the data, Black or African American participants (10.1%; 95% CI, 9.7%-10.6%) and Hispanic or Latino participants (22.5%; 95% CI, 21.6%-23.4%) were greatly underrepresented.

Carlos del Rio
Michele P. Andrasik

“Although we did not find large gaps in representation, our study underscores the issue of chronic, low-level marginalization,” Julie K. Silver, MD, who works in the department of physical medicine and rehabilitation at Harvard Medical School, Massachusetts General Hospital and elsewhere, told Healio.

“Low-level marginalization, while dismissed by some people, is extremely important,” Silver said. “For example, the well-documented issue of paying women almost as much as men about 85 cents on the dollar highlights deeply troubling ethical concerns and undeniable toxicity for women and their families that low-level marginalization can have.”

Carlos del Rio, MD, Infectious Disease News Editorial Board Member and executive associate dean at Emory University School of Medicine, explained that although the study shows that women are overrepresented in vaccine studies, they have been underrepresented in in other types of studies, including HIV studies, leading the FDA to limit the approval of some medications.

“Work is being done at different levels [to include more underrepresented populations in trials] and a field that has led the way has been HIV,” del Rio said. “Having community members in study protocol teams makes a huge difference.”

According to del Rio, the National Academies of Sciences, Engineering, and Medicine has put together a committee that is exploring how to improve the inclusion of women and minorities in clinical trials.

Flores suggested stronger policies to ensure that researchers are collecting and reporting trial population demographic data. The study found that just 58.3% of trials reported race and 34.3% reported ethnicity.

“There are multifaceted barriers to inclusion in clinical trials, in every step from design to implementation. In our study, we cited provider biases, like when medical providers refer only certain populations to clinical trial opportunities, and we touched on the justified medical mistrust that patients and research participants feel,” Flores told Healio.

“As researchers we need to make reporting of these demographic pieces a priority when we describe our trials,” Flores said. “I also believe ensuring that our health care workforce and our clinical trial researchers ‘look like’ and are representative of the whole population is an excellent start to increase diversity among clinical trial participants.”

Michele P. Andrasik, PhD, EdM, director of social and behavioral sciences and community engagement and senior staff scientist in the vaccine and infectious disease division at Fred Hutchinson Cancer Research Center, said there is “clear evidence that Black, indigenous and people of color (BIPOC) recruitment goals are needed proactively to achieve equity.”

“We know from other studies that BIPOC people are less likely to be referred to prophylactic treatment (X-rays, evaluations, etc.), and that BIPOC patients are more often seen as noncompliant or uncooperative, which may influence referral to clinical trials,” Andraski said. “Given [that], more provider training or awareness on the importance of clinical trials and participation among BIPOC individuals [are needed].”