Older Adults, Minorities Underrepresented in COVID-19 Vaccine Trials

The COVID-19 Prevention Network (CoVPN), established by NIAID to enroll volunteers for coronavirus-related clinical trials, has more than 400,000 people in its registry so far, and about 19 percent are between the ages of 65 and 74, according to CoVPN Executive Director Jim Kublin, M.D. Only 4 percent, however, are older than 74. (It's important to note that these numbers represent those interested in volunteering for the trials, not necessarily those who are actively participating.)

Pfizer reports that 48 percent of its volunteers enrolled in U.S. clinical trials are between the ages of 56 and 85, but does not have information specific to those 65 and up. Moderna did not respond to AARP's request for information on the ages of its clinical trial participants, but the University of Maryland's Chen, who serves as an investigator at one site testing Moderna's vaccine candidate (out of 100 sites taking part in the clinical trial), says about 17 percent of participants enrolled at his site are 65 and older.

Enrolling more older adults “is a critical need for us,” Kublin says. “And not just those who are over 75, but frankly, we need more people over 50 as well.”

Efforts to increase participation are underway

Testing a vaccine in a group of people that does not accurately represent the population bearing the burden of disease has serious implications.

"On a practical level,” it means researchers can't be sure whether the vaccine “will be effective in those populations,” Inouye says. “And that's really important, because there's things you could do to make it more effective,” such as increasing the dose, requiring two shots or adding an ingredient that helps to boost the body's immune response to the medicine.

Another factor to consider: Side effects. “You don't know if there are serious side effects if it hasn't been tested in the target population that needs it,” Inouye adds.

Efforts to increase participation among older adults and minorities in the current vaccine trials are not unique to the coronavirus pandemic. Both populations have long been underrepresented in trials across a range of treatments. And “the entire vaccine community has been grumpy about that for some time,” says William Schaffner, professor of medicine and an infectious disease expert at Vanderbilt University.

The unethical treatment of Black Americans in past studies continues to fuel mistrust of medical research in minority communities today, Chen says, pointing to the Tuskegee Study as an example. And in older adults, low participation has a lot to do with study design, Inouye says.

Older adults “need people who are trained to communicate with people who are hard of hearing or visually impaired. Sometimes they need their family members to be present or to give proxy consent,” she explains. Many studies also require participants to check in with a smartphone or video chat.

"A lot of these obstacles can be easily overcome, if they're just thinking about it … and are willing to invest the extra time and resources,” Inouye adds.

To reduce technological barriers older adults might face, the COVID-19 Prevention Network recently launched a call center (866-288-1919 toll-free) to answer questions and enroll interested volunteers. The network is also working with faith leaders in minority communities to help build trust and generate interest in the trials. Study sites across the country are taking similar actions — partnering with local organizations and businesses in communities hit hardest by the virus to increase enrollment and dispel myths about the trials.

Participation doesn't come without risk

Another factor that is likely preventing people from signing up for vaccine studies: safety concerns. A national survey from the Pew Research Center shows that the number of Americans who intend to get a vaccine to prevent COVID-19 is dropping, and a lot has to do with unease over the rushed development process. But as Kublin notes, the trials “are following the very stepwise process that we routinely do for vaccines,” only the timeframe has been compressed.

Plus: “The stakes are just way too high,” Inouye adds. “Even though [drug companies] are under a lot of pressure to rush things, they know they only need to have one terrible side effect to shut down everything.”

That's not to say there are no risks associated with participating in a clinical trial. All volunteers — including those injected with the placebo — can expect some pain, redness and swelling at the injection site, similar to a flu shot, Chen says. Some participants have also reported fevers and achy joints.

In early September, AstraZeneca paused its trial because of a suspected adverse reaction in one participant, but the odds of a severe side effect occurring are pretty rare, Inouye says. “What I would say is that anyone who volunteers in a trial is going to be monitored so closely that the chances of something really serious happening are there but are diminishingly small,” she adds.

Another risk to consider: A false sense of protection. Volunteers will not know whether they received the vaccine or the placebo, making it all the more important to continue preventive measures that reduce exposure to the virus, Chen says.

"We don't want our older adults who are in the study to say, ‘I think I might have gotten a vaccine. So I'm gonna go out; I'm going to take my vacation now; [I'm going] to go to the bars, go to the restaurants or whatever,'” he adds.

Participating in a large research study is not for everyone, Chen notes. However, he's hopeful that with more education and outreach, most of the population, including older adults and minorities, will choose to get vaccinated, either in the trials or shortly after a vaccine's approval, as part of the global effort to defeat COVID-19.

"Vaccines don't work unless they're used. They could be on the shelf and licensed, but if they're not used and taken up in the population, it doesn't help,” he says.