Public Health Watch: Efforts Needed to Improve Diversity in COVID-19 Vaccine Trials

Racial disparities in the impact of the COVID-19 pandemic have been well documented.

Compared with White Americans, Black Americans are 10% more likely to get infected with the virus, 3 times as likely to be hospitalized with severe disease, and twice as likely to die from it, according to data from the US Centers for Disease Control and Prevention. Hispanic Americans have a 30% higher risk for infection, a similar risk for hospitalization and death as Black Americans.

And yet, when it comes to the clinical trials for the vaccines from Pfizer/BioNTech, Moderna, Johnson & Johnson, and AstraZeneca, people of color have been disproportionately underrepresented. In a letter to the editor published on April 10th in The Lancet, researchers from King’s College London called on companies and governments to take steps to ensure that “access to trials and vaccinations shifts from being equal to being equitable.” This means study recruitment and participation designs should consider ethnicity, in addition to other characteristics such as age and gender.

“The causes of underrepresentation of minority groups in trials are likely to be multifactorial in nature and possibly similar to barriers to access to healthcare in general,” letter coauthor Rashmi D'Souza, a research fellow at King’s College London told Contagion. “Awareness of opportunity, practical access, understanding of the process, risks and benefits and trust in the healthcare system are some barriers.Research methodology needs to address this disparity and include proportionate efforts to target these barriers. Some groups may need more support, time, and encouragement to participate equally. This makes for more valid and applicable research.”

This includes efforts to build trust in communities of color, through education and outreach.

Indeed, D’Souza and his colleague at King’s, Ingrid Wolfe, PhD, who both focus on issues related to children’s health, who have assessed the vaccine trials for diversity found no evidence of “active exclusion of any particular groups of patients,” D’Souza said. In fact, they found examples of efforts to increase minority group participation in trials,” he said.

However, significant gaps remain. Clinical trials for the Pfizer/BioNTech vaccine collectively enrolled nearly 38,000 patients, all but 10,000 of them in the United States. Yet, Black Americans accounted for 9.3% of trial participants, despite making up 12.5% of the national population, D’Souza and Wolfe found. Similarly, 4.3% of trial participants were Asian American, a group that accounts for 5.8% of the US population, according to Census figures.

Meanwhile, clinical trials for the Moderna shot, all of which were performed in the US, had sample populations that were 79.2% White, 10.2% Black, and 4.6% Asian. Phase II/III trials of the Oxford/AstraZeneca vaccine in the UK enrolled the least diverse samples, with 95% of participants identifying as White and just 0.18% as Black. Black people make up about 3% of the UK’s population, based on government figures.

“Rather than a specific exclusion, perhaps it is that current trial recruitment methodologies—equal recruitment strategies—result in disproportionate participation [and that] some patient groups may need more support than others,” D’Souza said. In the US, of course, there is a history of distrust of medical research among communities of color. However, improved recruitment and support strategies could mitigate at least some of this—and that could be key to the success of COVID-19 vaccination campaigns.

“We agree that increased participation from minority groups may itself increase trust and vaccine-uptake within these groups,” D’Souza noted.