The Pfizer-BioNTech and Moderna vaccines both rely on a genetic technology that has never before yielded a vaccine that won regulatory approval. They are authorized for emergency use only. Studies of their safety, including the cases of an Alaska health care worker and a Boston doctor who experienced severe allergic reactions after receiving their shots, are still underway.
And as Dr. Wilson crawled into bed at 10:30 on a weekday morning, she could not help but be “hyper-aware,” she said, “that I had just been vaccinated with this novel vaccine.”
Navigating a brain fog
As vaccines go, experts have agreed, the two being distributed now elicit more reactions than most.
At the Sundale Nursing Home in Morgantown, W.Va., Betty Shannon, 81, said some fellow residents had an upset stomach after becoming some of the nation’s first seniors to receive a Covid-19 vaccine.
Lorenzo Alfonso, 34, a nurse assistant in California, was unusually tired and achy.
Delayna Frint, a nurse in Highlands Ranch, Colo., said her arm was so sore after the shot that in order to hang intravenous therapy bags, she had to lower the stands.
But for infectious-disease experts, a nation down for the count with post-vaccine malaise would be the best news in a long time. The side effects dissipate within a few days, and they are a signal, the experts say, that the vaccine is working.
“We call them ‘side’ effects, but it’s really just an effect,” said Dr. Paul Offit, a University of Pennsylvania vaccinologist who is a member of the Food and Drug Administration’s vaccine advisory panel. “This is what your immune response does when it’s responding to an infection.”
The vaccines each work by prompting the body to make a particular protein that the coronavirus uses to enter human cells; neither exposes the recipient to the virus itself. The presence of that protein in the body sets off the production of new antibodies that can destroy the protein — the key to providing protection against a future invasion of the actual virus. But the process also releases substances that can cause inflammation, which can result in fever, fatigue, headache and other symptoms.