Moderna’s coronavirus vaccine appears to create as strong an immune response in older people as it does in younger adults. That’s a positive sign, because many vaccines don’t work as well in the elderly.
“This is very promising but it’s also somewhat surprising,” said David Dowling, an immunologist and professor at Harvard Medical School, who studies vaccines.
Older people are at higher risk for severe illness from , according to the Centers for Disease Control and Prevention. People 50 to 64 years old are four times more likely to be hospitalized and 30 times more likely to die from than people ages 18 to 29. Those ages 65 to 74 are five times more likely to be hospitalized and 90 times more likely to die.
The Moderna study was conducted by researchers at Emory University in Atlanta and included two groups of 20 people each, one made up of people ages 56 to 70 and one of people 71 and over. Participants were enrolled in Atlanta, Seattle and Bethesda, Maryland. The findings were compared to findings previously reported among vaccine recipients 18 to 55.
“The immune responses were very comparable to that of the young adults,” said Dr. Evan Anderson, a professor of infectious disease at Emory University Medical School and lead author on the paper.
Moderna’s mRNA-1273 experimental vaccine is now in Phase 3 clinical trials in the United States. It is considered a front-runner among the four candidate vaccines in end-stage trials. There is no data available yet on how well it protects people from getting .
It has long been known that a person’s immune system weakens as they get older.
“With increasing age, our immune responses generally decline and a number of different vaccines tend to not work as well as we get older. That’s why we have the high dose influenza vaccine for people 65 and above,” Anderson said. “The fact that that 100 microgram dose (of Moderna’s COVID vaccine) seemed to be sufficient to generate a similar immune response in older people is a very pleasant finding.”
There also have been concerns that some vaccines might not work at all for seniors, limiting their options or requiring they wait until newer vaccines become available. Another approach known as “ring immunization,” in which the at-risk person doesn’t get vaccinated but everyone around them does, would require more vaccine, too.
The findings don’t show whether the experimental vaccine will give people immunity to the SARS-CoV-2 virus, but they are “heartening,” Anderson said.
The study encompassed only 40 people and almost all were white, so the researchers acknowledged that a broader study population was needed to confirm the results. has disproportionately affected communities of color.