Reports of Anaphylaxis After Receipt of mRNA COVID-19 Vaccines in the US—December 14, 2020-January 18, 2021

A total of 66 case reports met Brighton Collaboration case definition criteria for anaphylaxis (levels 1, 2 or 3):47 following Pfizer-BioNTech vaccine (reporting rate of 4.7 cases/million doses administered), and 19 following Moderna vaccine (2.5 cases/million doses administered)

SPS commentary:

The authors note 21 (32%) of the 66 cases had a prior episode of anaphylaxis from other exposures; these included vaccines (rabies, influenza A[H1N1], seasonal influenza, unspecified), contrast media (gadolinium-based, iodine-based, unspecified intravenous), unspecified infusions, sulfa drugs, penicillin, prochlorperazine, latex, walnuts, unspecified tree nuts, jellyfish stings, and unspecified exposures.

They conclude that anaphylaxis following COVID-19 vaccination is a rare event, and benefits of vaccination far outweigh the risk of anaphylaxis, which is treatable.

Journal of the American Medical Association