Older adults are especially susceptible to infection by the virus, and at higher risk of falling critically ill and dying, at least partly because their immune systems have lost strength with age. Public-health officials and scientists are concerned that a weakened immune system could also limit the effectiveness of a coronavirus vaccine, just as it has sapped the power of other shots in older people.
“It would not be particularly encouraging if we have a vaccine that’s capable of protecting 20-year-olds who probably have a pretty low risk anyway of getting sick, and doesn’t work at all for people over 65,” Francis Collins, director of the National Institutes of Health, said in an interview.
Older adults have been especially hard hit by the new coronavirus. Between March and mid-June, Americans over the age of 65 had the highest rate of hospitalization among all age groups, about double the rate for people 50 to 64 years old and five times the rate for 18- to 49-year-olds, according to the Centers for Disease Control and Prevention.
Vaccines will be crucial, public-health experts say, to stopping the spread of the virus. More than 100 are in development and more than a dozen are in human testing, according to the World Health Organization.
The Food and Drug Administration is working with companies to make it easier for experimental vaccines to be tested in older adults earlier during clinical trials, and alongside younger subjects, an agency spokesman said.