CDC data for the Pfizer and Moderna COVID-19 vaccines trials show something a bit shocking: a diverse sample population. 

Roughly 10% of the case-patient participants identified as Black. Thirteen percent identified as Hispanic/Latino; a combined 13% identified as Asian or Pacific Islander, American Indian or Alaska Native, multiple or missing races; while case-patients identifying as white totaled 64%. For context, 2019 Census data defines the United States population as 12.8% Black; 18.4% Hispanic or Latino; a combined 15.2% for American Indian, Alaska Native, Asian, Native Hawaiian and Other Pacific Islander, multiple or missing race; and 72.0% white.

While the COVID-19 vaccine trials don’t exactly match the population estimates of the United States, they are closer than trials have historically been. Previous FDA reports on clinical trials found that those identifying as Black or African American accounted for roughly 5% of sample populations, while Hispanic and Latino individuals made up about 1%, Asian Americans 6%, and Native Americans were excluded from nearly two thirds of trials examined.

Diversity is essential in clinical trials to ensure medications and treatments are safe and effective for the populations they’re intended to help. Unfortunately, clinical trials have a long history of underrepresenting women and people of color, resulting in treatments designed primarily for white men. Underrepresented groups are therefore more skeptical to receive new treatments, putting them and their communities at greater risk.

Why do trials lack diversity?

Lack of trust in the medical system prevents many people of color from participating in clinical trials, particularly members of the Black community. The United States has a history of deceptive and biased medical treatment. Although groups are working to mend that relationship and build trust in public health, some clinical trial practitioners still do not share information about clinical trials with all demographics. 

There is also a lack of clear, targeted communication about trials. While individuals may know about a trial, they may not know details like what the trial entails, if they’re eligible, if they can fit it in their schedule, if they’ll have to pay for it. 

Logistics concerns are another barrier to entry. Hourly workers may not be able to afford taking off work for a trial. They may need additional childcare or domestic support. They may lack reliable transportation and be unable to commute for treatment. Funding for research tends to go to larger institutions which may be far from volunteers’ typical medical provider. Especially rare conditions may only be researched in one or a few cities in the world, requiring volunteers to relocate for the duration of the trial. While trials do offer financial support through deductions and compensation for expenses, the details of this support can be hard to find, difficult to understand, and inconvenient to pursue. 

How can we promote diversity in clinical trials? 

• Increase targeted communication for targeted demographics. Communities need to know about these trials before than can sign up for them. Researchers will have greater success recruiting if they cast a wide net while developing specific communications for each demographic that acknowledge common concerns among community members and address them clearly.
• Partner with historically Black colleges and universities, medical institutions, and healthcare providers in areas where more demographics live or typically go for treatment. Individuals will be more likely to volunteer if the research center is trustworthy easily accessible.
• Design more inclusive trials that are convenient for all demographics. Flexible scheduling, at-home visits, and mobile check-ins, for example, can make it easier for volunteers to fit the trial into their lives.
• Invest in patient support throughout the trial. Personal support for volunteers, especially during trials that require a lot of time or energy from volunteers, can encourage individuals who might otherwise feel too scared or overwhelmed to volunteer. Hiring patient advocates and coordinators who are close to a given community can foster trust and help patients feel seen in what might be a stressful time.
• Be ambitious and transparent with sampling. Teams should hold their colleagues and partners accountable for conducting truly representative trials and work together to build trust among diverse communities. 

Sample diversity is essential for adequate testing and safe, quality healthcare for all. Increased focus on equal representation in clinical trials is a step in the right direction, but the health of our communities requires ongoing effort from researchers.