U.S. FDA investigating 5 allergic reactions after Pfizer shot in U.S

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Pharmacy manager Larren Suh displays the Pfizer-BioNTech coronavirus disease (COVID-19) vaccine at Massachusetts General Hospital in Boston, Massachusetts, U.S., December 16, 2020. Craig F. Walker/Pool via REUTERS

NEW YORK, Dec 18 (Reuters) - The U.S. Food and Drug Administration is investigating around five allergic reactions that happened after people were administered Pfizer Inc (PFE.N) and BioNTech SE's COVID-19 vaccine in the United States this week, a top FDA official said late on Friday.

Dr. Peter Marks, director of the FDA's Center for Biologics Evaluation and Research, said at a press conference that the allergic reactions had been reported in more than one state, including in Alaska. read more

Marks also said that a chemical called polyethylene glycol (PEG) that is an ingredient in the Pfizer vaccine - as well as the Moderna Inc (MRNA.O) vaccine authorized on Friday - "could be the culprit" causing the reactions.

Marks said that allergic reactions to PEG could be somewhat more common than previously understood.

The cases in Alaska were similar to two cases reported last week in Britain.

Britain's medical regulator has said that anyone with a history of anaphylaxis, or severe allergic reactions to a medicine or food, should not be given the Pfizer-BioNTech COVID-19 vaccine. read more

But the U.S. Food and Drug Administration has said that most Americans with allergies should be safe to receive the vaccine. It said only people who have previously had severe allergic reactions to vaccines or ingredients in this particular vaccine should avoid getting the shot. read more

On Friday, the FDA said the Moderna vaccine should not be given to individuals with a known history of a severe allergic reactions to any components of the shot.

The regulator is also requiring that appropriate medical treatments for immediate allergic reactions must be available when the shot is administered in case of an anaphylactic reaction.

Pfizer could not be immediately reached for comment.

Reporting by Caroline Humer; editing by Diane Craft

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