There aren’t enough seniors participating in COVID-19 treatment and vaccine trials, and the result could be drugs that are unavailable or inappropriate for the elderly, according to the authors of a new study.

Researchers examined the rate at which older participants were excluded in federally registered COVID-19 clinical trials through June 1. They found that older adults are “highly likely” to be excluded from more than 50% of COVID-19 clinical trials and fully 100% of COVID-19 vaccine trials.

“Our worry is that without clinical trial testing, older adults will ultimately be denied treatments and vaccines secondary to safety concerns,” study author Churl-Su Kwon, M.D., told McKnight’s. “Thus, equitable distribution to this population will not be possible.” 

Legitimate health safety reasons exist for excluding some older adults in drug trials, and their involvement may slow trial progress and increase costs. In addition, some have argued that only younger populations need to be vaccinated to achieve herd immunity against COVID-19. But difficulties of inclusion are surmountable, and the current degree of exclusion is unwarranted in light of the pandemic’s outsize burden on older adults, the researchers contend. 

“[G]eriatricians or those with aging expertise can assist with enrollment and safe management of older adults in clinical trials,” said Kwon, of the Departments of Neurology and Neurosurgery and Icahn School of Medicine at Mount Sinai in New York City. “While requiring extra time and effort, this will be counterbalanced by the immeasurable increase in validity and usefulness of the results. This will not occur without forethought and intent.”

Safety and effectiveness

In contrast, excluding older adults means that the ability to evaluate safety and effectiveness of COVID-19 treatments and vaccines in those at highest risk will be systematically limited, Kwon added. Antibody responses to vaccines can be decreased in older adults, for example. Although this problem may be solved by increasing dosages, the addition of enhancers, or repeat shots, “these approaches cannot be applied or tested without including older adults in clinical trials,” he argued.

Meanwhile, the high level of herd immunity required (67%) to reduce overall transmission, coupled with the fact that many settings such as nursing homes are composed nearly exclusively of older adults, makes it critical that they be included in trials and be vaccinated, the authors wrote.

“The important take-home message is that older adults, who are the target population of COVID-19, need to be included in any clinical trials of treatment or vaccines,” Kwon concluded. “This should be mandated.”

The study was published in JAMA Internal Medicine.