CHICAGO (Reuters) – Results from an initial safety study of Moderna Inc’s coronavirus vaccine candidate in older adults showed it produced neutralizing antibodies to the virus at levels similar to those seen in younger adults, with side effects to the roughly on par with high-dose flu vaccines, the researchers said Tuesday.
The study, published in the New England Journal of Medicine, offers a more complete picture of vaccine safety in the elderly, a group at increased risk for serious complications from COVID-19.
The results are reassuring because immunity tends to weaken with age, Dr Evan Anderson, a lead investigator of the study at Emory University in Atlanta, said in a telephone interview.
The study was an extension of Moderna̵
Overall, the team found that in older adults who received two injections of the 100 microgram dose 28 days apart, the vaccine produced immune responses roughly in line with those seen in younger adults.
Moderna is already testing the higher dose in a large Phase III trial, the final stage before requiring clearance or emergency approval.
Side effects, which included headache, fatigue, muscle aches, chills, and pain at the injection site were considered to be mainly mild to moderate.
In at least two cases, however, the volunteers had severe reactions.
One developed a grade three fever, which is classified as 102.2 degrees Fahrenheit (39 ° C) or higher, after receiving the lowest vaccine dose. Another developed fatigue so severe that it temporarily impeded daily activities, Anderson said.
Typically, the side effects occurred soon after receiving the vaccine and resolved quickly, he said.
“This is similar to what many older adults will experience with the high-dose flu shot,” Anderson said. “They might feel sick or have a fever.”
Norman Hulme, a 65-year-old senior media developer at Emory who took the lowest dose of the vaccine, said he felt compelled to take part in the trial after seeing first responders in New York and Washington state fight the virus.
“I haven’t had any side effects,” said Hulme, who grew up in the New York area.
Hulme said he is aware that Moderna’s vaccine uses new technology and that there may be a risk in taking it, but said: “someone had to do it.”
Reporting by Julie Steenhuysen; Editing by Bill Berkrot