The United States is looking at the reasons why a handful of people suffered severe allergic reactions shortly after receiving vaccines against the Pfizer coronavirus vaccine, an official at the National Institute of Allergy and Infectious Diseases told CNBC on Monday.
The study – which is still in its early planning stages – is expected to include “several hundred” people with a history of severe allergic reactions, said Alkis Togias, head of NIAID’s Allergy, Asthma and Respiratory Biology branch. His department will lead the study, which researchers hope will begin in a few weeks, although the timing is not guaranteed. While the reactions were reported by people who received Pfizer’s shot, the study could examine vaccines made by both Pfizer and Moderna.
Togias said researchers at NIAID, an agency within the National Institutes of Health, became interested in the rare phenomenon after reporting that several people had reactions to the Pfizer vaccine, which he described as anaphylaxis, a severe allergic reaction that can life threatening. Just last week, an Alaska clinician suffered anaphylactic symptoms about 10 minutes after receiving the Pfizer vaccine, becoming the third medical worker in the state to suffer an adverse reaction to the new drug.
“We’re a little worried that people who have had a lot of allergies who have had reactions like this to all sorts of things, not just vaccines, may be afraid to get vaccinated now,” Togias told CNBC. “We don’t want that to happen. We want to find a way for them to get vaccinated,” he added.
President Donald Trump’s coronavirus vaccine tsar Moncef Slaoui mentioned the study in a briefing on Operation Warp Speed earlier Monday.
“There is now advanced planning for a study of highly allergic individuals in clinical trials to test Moderna and Pfizer vaccines and try to understand the immune mechanisms that underlie any reactions,” he said.
The study comes as the federal government begins distributing nearly 8 million doses of Covid vaccine nationwide this week, following the delivery of 2.9 million doses of Pfizer vaccine last week. The US is delivering 5.9 million doses of Moderna vaccine this week, as well as 2 million doses of Pfizer vaccine, Secretary of Health and Human Services Alex Azar said on Monday. As of Sunday, 556,208 Americans have been shot, according to the Centers for Disease Control and Prevention.
It is not clear why some people experience allergic reactions.
Both Pfizer and Moderna vaccines use messenger RNA or mRNA technology. It is a new approach to vaccines that use genetic material to elicit an immune response against the virus. US health officials say the vaccines are safe, with only 10% to 15% of clinical trial volunteers reporting side effects that were “significant.”
Fatigue, headaches and muscle aches are the most common side effects of the Moderna vaccine, along with some rare symptoms such as nausea or intractable vomiting and swelling of the face that are likely triggered by blows, according to the Food and Drug Administration. Some side effects were difficult to shake off, although most were resolved within a week, the FDA said.
Medical experts say that allergic reactions to vaccines are rare, but can sometimes happen. However, the FDA said on Thursday that it was analyzing allergic reactions that occurred after people were given the Pfizer vaccine. Doran Fink, deputy director of the FDA’s Division of Vaccines and Related Products, said the agency will consider whether additional recommendations on vaccines are needed after the investigation.
“At the moment, we do not have enough data to make a definitive recommendation in one way or another,” he told the Advisory Committee on Vaccines and Related Biological Products during a meeting.
Togias said he hopes the NIAID study will shed light on allergic reactions. He said the study could include people who do not suffer from allergic reactions so that researchers can make comparisons.
Before researchers can begin the study, the agency will have to develop a very detailed protocol that will have to be approved by the FDA, Togias said. After receiving an OK from the FDA, it will then need to be reviewed and approved by an ethics committee.
“Of course, when everyone hears a study about the vaccine, we try to be sensitive and move fast,” he said. “But it’s not something we can project today and start tomorrow.”