But federal data show that despite guidelines from the National Institutes of Health recommending more diversity in clinical trials, people of color are largely underrepresented.
A study released Friday in JAMA Network Open suggests that the disparities started long before the pandemic magnified existing inequities.
According to the report, issued by researchers at Harvard Medical School, the Fred Hutchinson Cancer Research Center in Seattle and the Emory University School of Medicine in Atlanta, 78% of all participants in clinical trials dating to 2011 were white. Latinos, who are 18% of the U.S. population, were 12% of participants and Black Americans, who are more than 12% of the total population, accounted for 11% of participants.
Asian, Native Hawaiian and Pacific Islander participants were equitably represented in vaccine trials compared to the total population, the authors found.
"The COVID-19 pandemic and its devastating impact, particularly on BIPOC [Black, Indigenous and people of color] communities and older adults, is a painful reminder of the health disparities in our country," said a co-author, Dr. Steve Pergam, an associate professor in the vaccine and infectious disease division at the Fred Hutchinson Cancer Research Center. "This collaborative work highlights a problem that's plagued the scientific community for too long — inadequate representation in clinical trials."
Pergam and his colleagues set out to learn whether enrollment in clinical trials accurately reflected the vast diversity of people in the U.S. Looking at the last decade, the team found that white adult women were overrepresented in clinical trials, while people of color and those over age 65 were underrepresented.
The team's findings reflect a broader, ongoing issue exacerbated by the coronavirus pandemic. Older white women are being vaccinated at a higher rate than Blacks, Latinos, Asians and Native Americans, according to a recent report by the Centers for Disease Control and Prevention.
The CDC report found that among the 13 million people who received first doses of a vaccine when they became available in mid-December, more than 60% were women, and more than 50% were over 50.
Recent CDC numbers show that COVID-19 hospitalizations and deaths are more likely to occur among Native Americans, Latinos and Blacks.
"It's only fair that if we're asking people to participate in this effort, it's our obligation to make sure that those trials are reflective of who those vaccines should go to," Pergam said. "It's even more important when it comes to COVID-19, where there is a tremendous amount of disparity in terms of who gets the disease and who's dying from the disease."
The disparities continue to play out as states struggle to vaccinate millions of people. In California, where Latinos are about 40% of the population, only 16% of those vaccinated so far are Latino, according to data released last week by California public health officials. Black residents are about 7% of the population but just 3% of those who have been vaccinated.
When looking at vaccination levels county by county, the numbers are even starker. In Los Angeles County, Latinos make up half of all residents but only 23% of vaccinations. And 4% of those who have been vaccinated are Black, even though they are 8% of county residents.
According to the CDC, race and ethnicity are risk markers for other underlying conditions that affect overall health outcomes, including access to medical care and exposure to the coronavirus at work. Yet Black and Latino people also report higher levels of vaccination hesitance and distrust compared to white Americans, according to a recent survey by the COVID Collaborative, a coalition of national experts on health, education and the economy.
One way to overcome hesitance is to establish trust between medical professionals and the communities they serve, said Michele Andrasik, a staff scientist in Fred Hutchinson's vaccine and infectious disease division.
"Clinical trials are a way to open the door to a lot of people and really start a positive relationship with research, with health care systems," she said. "It can really open up possibilities and change someone's view of the medical infrastructure."
Andrasik, who co-authored the JAMA study with Pergam, worked on recent coronavirus clinical trials for Moderna, AstraZeneca, Johnson & Johnson and Novavax. While the Moderna Phase 3 trial appeared to be more representative of the greater population — 37% of participants reflected communities of color, and more than 80% worked in jobs that posed risks of infection — the other trials were not.
In the AstraZeneca trial, more than 80% of participants were white.
The number was slightly lower in the Johnson & Johnson Phase 3 trial, in which 74% of participants were white.
"Covid has opened peoples' eyes and ears to long-term inequities," Andrasik said. "We are nowhere near having the type of representation that we need to have to ensure trustworthiness of our institutions."
This story originally appeared on NBC News.