Questions surrounding the coronavirus vaccine and allergic reactions heightened this week after a health care worker in Alaska developed a severe reaction requiring hospitalization shortly after receiving the Pfizer COVID-19 vaccine, despite having no history of allergies.
Here's what we know so far about the coronavirus vaccine and potential allergic reactions:
Should you get the vaccine if you have a history of allergic reactions?
Currently, the Centers for Disease Control and Prevention recommends anyone with an allergy to "any component" of the Pfizer coronavirus vaccine not get the vaccine.
Those with a history of allergies, however, should consult with their doctor first, the agency said, calling "a history of severe allergic reaction such as anaphylaxis to any vaccine or to any injectable therapy... a precaution, but not contraindication, to vaccination."
"These persons may still receive vaccination, but they should be counseled about the unknown risks of developing a severe allergic reaction and balance these risks against the benefits of vaccination," the CDC's guidance reads.
It also recommends such patients be monitored for at least 30 minutes, while those with no history be monitored for at least 15 minutes.
The U.K's Medicines and Healthcare products Regulatory Agency updated its guidance last week to advise people who have a history of "significant" allergic reactions to forgo the vaccine developed by Pfizer and BioNTech. The updated guidance came after two members of Britain's National Health Service experienced allergic reactions to the shot, though both are recovering well, according to the national medical director for the NHS.
"We know from the extensive clinical trials that this was not a feature, but if we need to strengthen our advice now that we have had this experience in vulnerable populations, the groups selected as a priority, we get that advice to the field immediately," Dr. June Raine, head of the MHRA, told a U.K. government select committee.
Vaccine expert, Dr. Paul Offit, who served on the Food and Drug Administration's vaccine advisory panel, said he believes the recommendations out of the United Kingdom were "premature and ill-considered."
"There are tens of millions of people in the United States who carry epipens because they have severe allergic reactions," Offit said. "So that [recommendation] has been modified to something far more sensible."
According to Offit, those who have vaccine allergy history or a history of reactions from injectable therapy would be at greatest risk.
"However, if you have a severe allergic response, otherwise - so for example, people commonly have peanut allergies or egg allergies, other food allergies - that you still can get this vaccine, you just need to wait for 30 minutes in the area where you've gotten that vaccine so that if you do have an allergic reaction, somebody would be able to give you a shot of epinephrine to reverse it," he said. "And then we for everybody else, we make a recommendation we always make with vaccines, which is that whenever you get a vaccine, you should hang around for about 15 minutes to make sure you didn't have a severe allergic reaction because one out of every million doses roughly of vaccines is complicated by severe allergic reaction."
He noted that "we don't really know what happened in the United Kingdom."
"I really do think in the next couple months, we'll be able to dissect out what part of that vaccine may have been the problem," Offit said.
How are health officials preparing for the possibility of such reactions?
In Illinois, health experts have been prepared for the possibility of allergic reactions and have monitored health care workers who are among the first to receive the vaccine.
"Much has been made of a couple of recent cases documented in the United Kingdom of individuals who experienced severe allergic reactions," said Dr. Rachel Rubin, a senior medical officer for the Cook County Department of Public Health.
Rubin said county guidance "will ensure that appropriate medical treatment is available to manage any immediate allergic reactions" and that all people who receive the vaccine will be monitored for at least 15 minutes after receiving the shot.
The Alaska worker's reaction is the first reported in the U.S.
During a media briefing Wednesday, health officials said a middle-aged woman at the Bartlett Regional Hospital in Juneau, Alaska had to be hospitalized overnight after she developed a severe reaction Tuesday evening, NBC News reports.
The woman had no history of allergies and had never experienced anaphylaxis, a severe and life-threatening allergic reaction, health officials said.
Pfizer said in a statement that the company is "working with local health authorities to assess" the reaction that occurred in Alaska, and will "closely monitor all reports suggestive of serious allergic reactions following vaccination and update labeling language if needed."
Dr. Jay Butler, head of the COVID-19 response at the Centers for Disease Control and Prevention, said the Alaska case is the only allergic reaction to the Pfizer-BioNTech vaccine reported in the United States so far.
Are allergic reactions to vaccines common?
Allergies are always a question with a new medical product, but monitoring COVID-19 vaccines for any other, unexpected side effects is a bigger challenge than usual. It's not just because so many people need to be vaccinated over the next year. Never before have so many vaccines made in different ways converged at the same time — and it’s possible that one shot option will come with different side effects than another.
The first vaccine beginning widespread use in the U.S. and many Western countries, made by Pfizer Inc. and Germany’s BioNTech, and a second option expected soon from competitor Moderna Inc. both are made the same way. The Food and Drug Administration says huge studies of each have uncovered no major safety risks.
But the allergy concern “points out again the importance of real-time safety monitoring,” said Dr. Jesse Goodman of Georgetown University, a former FDA vaccine chief.
And authorities have multiple ways of tracking how people fare as these COVID-19 vaccines, and hopefully additional ones in coming months, get into more arms.