Risk Estimation for Allergic Reactions to Covid-19 mRNA Vaccines

An official guideline for managing the serious allergy concerns in the present pandemic.

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Incidents of serious allergic reactions — called anaphylaxis — have occurred within a few minutes of receiving the mRNA vaccines for Covid-19 in the U.S. and U.K. Anaphylaxis is life-threatening if untreated, and usually occur within minutes of allergen exposure. Symptoms include hives; swelling of the mouth, lips, tongue, or throat; breathlessness, wheezing, or chest tightness; or low blood pressure or consciousness loss.

Fortunately, vaccine anaphylaxis is incredibly rare. Historically, only 33 anaphylaxis cases have been documented out of 25 million vaccine doses. In the U.S., there were 21 anaphylaxis cases from the 1,893,360 million first doses of Pfizer-BioNTech mRNA vaccine administered. While the anaphylaxis rate is higher with the mRNA vaccine than regular vaccines — at about 11.1 vs. 1.3 in 1,000,000 doses — it’s assuring that there were no deaths or long-term side effects from the anaphylaxis cases.

Risk stratification

Nevertheless, understanding who is at risk for vaccine anaphylaxis would prevent any unnecessary mishaps. In that light, researchers at the Division of Rheumatology Allergy…