What people with allergies should know about covid vaccines

On Wednesday, two Alaska health workers also experienced reactions. One was too mild to be considered anaphylaxis. But the other, which happened in a middle-aged woman with no history of allergies, was bad enough to go to hospital, even after she received a pill of epinephrine.

“What’s happening looks very unusual to me,” said Dr. Kimberly Blumenthal, an allergist, immunologist and drug allergy researcher at Massachusetts General Hospital. Vaccine-related allergic reactions are usually rare, occurring at about one in a million.

Dr Blumenthal also said it was strange to see allergic reactions accumulate in just two places: Britain and Alaska. Zeroing insisted on the commonalities between the two hotspots, she said, researchers could find out where the problem came from.

British and U.S. agencies are investigating the causes, but no official has announced a direct link.

But Dr. Blumenthal suspects that they were connected to the scenes, as the reactions were immediate, occurring within minutes of the injection.

“We have to think it was relative because of the time,” she said.

And it is unknown whether a particular ingredient was to blame. The Pfizer vaccine contains only 10 ingredients. Most importantly a molecule called a messenger RNA, or mRNA – a genetic material that instructs human cells to produce a coronavirus protein called a spike. Once done, a spike teaches the immune system to recognize the coronavirus until it is shut down in the future. Messenger RNA, found naturally in human cells, is not likely to be compromised, and decays within about a day of being injected.

The other nine ingredients are a mixture of salts, fatty substances and sugars that stabilize the vaccine. None of these are allergens. The only chemical with a history of sensitizing reactivity is polyethylene glycol, or PEG, which helps pack the mRNA into an oily sheath, protecting it as it enters human cells.

But PEG is, in general, inert and widespread. It is found in ultrasound gel, laxatives like Miralax and injectable steroids, among other drugs and products, Dr. Blumenthal said. Despite the severity of the chemical, she said, “I have only seen one case of PEG allergy – it is, in fact, uncommon. ”