The race to find a coronavirus vaccine is advancing at an unprecedented pace. But as several vaccine candidates progress into their third and final phase of testing, a question concerning diversity is being pushed to the forefront: Are the participants on the receiving end of the needle an accurate representation of the American public, and especially the populations most affected by COVID-19?
To date, more than 204,000 Americans have died from a coronavirus infection, and 80 percent of these deaths have occurred in adults 65 and older, according to the Centers for Disease Control and Prevention (CDC). Minority groups have also been disproportionately impacted by COVID-19. Coronavirus infection rates are 2 to 3 times higher in communities of color, and Black Americans are more than twice as likely to die from COVID-19 than their white peers, federal data show. When it comes to severe illness, hospitalization rates among Black, Hispanic and Native Americans are 4 to 5 times higher than whites.
"We want to be assured that these vaccines perform well in these parts of the population where we really intend for them to protect the most,” says Wilbur Chen, M.D., a professor of medicine and chief of adult clinical studies at the Center for Vaccine Development and Global Health at the University of Maryland.
Current clinical trial enrollment numbers, however, show there's still work to do.
Minority, older adult participation lags behind experts’ expectations
Two out of 3 drugmakers with vaccine candidates that are considered frontrunners in U.S. clinical trials recently released details about the diversity of their participant pools. Pfizer, which plans to recruit 44,000 volunteers, says that about 27 percent of its U.S enrollees so far “have diverse backgrounds” — 12 percent are Hispanic, 8 percent are Black, 5 percent are Asian and about 0.6 percent are Native American. Meanwhile, Moderna reports that approximately 31 percent of its 27,232 participants are from communities of color. (The biotech company plans to enroll 30,000 participants in its phase 3 clinical trials.)
However, many experts argue that a well-represented participant pool should mirror the actual makeup of the U.S., and census data show that racial and ethnic minorities account for about 40 percent of the American population. What's more, because these groups have been hit especially hard by COVID-19, Anthony Fauci, M.D., director of the National Institute of Allergy and Infectious Diseases (NIAID), has said that he would like to see clinical trial participation among minorities at levels that are double their percentages in the population.
Sharon K Inouye, M.D., a geriatrician at Boston's Hebrew Senior Life and professor of medicine at Harvard Medical School, wants a similar goal set for older adult enrollment. People ages 65-plus account for about 16 percent of the U.S. population, according to the latest census estimates. But given the devastating and disproportionate toll the virus has had on older adults, Inyoue says around 40 percent of clinical trial participants should represent this group.
"What are you seeing in the trials today? Nowhere near 40 percent,” Inyoue says. “And so that is extremely worrying to me."