Even if you have a history of severe allergic reactions to vaccines, Pfizer and Covid shots are still a good idea, big study says

The Pfizer and Moderna coronavirus vaccines using messenger RNA are shown to be safe for people with a history of severe allergic reactions to vaccines, medications, or allergens, according to a study of more than 52,000 employees in the Mass General Brigham health-care system in Massachusetts.

In the study, published in JAMA Network Open, 474 participants reported a history of such allergic reactions, and significantly more suffered from allergic reactions following the mRNA vaccine than those who did not report a history of allergic reactions, 11.6% to 4.7%. The most common reaction was swelling in the skin. Despite these symptoms, 97.6% of the employees received two doses of an mRNA vaccine.

Lily Li, the study's lead author, said, "The results of this study can help guide expectations for patients with high-risk allergy histories. Symptoms such as hives and swelling may occur, particularly with the first vaccine dose, but most reported allergic symptoms did not impede completion of the two-dose mRNA vaccine series."