Cleve Clin J Med. 2021 Mar 1. doi: 10.3949/ccjm.88a.ccc075. Online ahead of print.
Recent reports of allergic reactions to the Pfizer-BioNTech and the Moderna COVID-19 vaccines have resulted in questions about how and to whom they can be safely administered. Although anaphylaxis was not observed in clinical trials for either vaccine, there have been 21 reported possible cases of anaphylaxis associated with the Pfizer vaccine (11.1 cases per million doses administered) and 10 possible cases associated with the Moderna vaccine (2.5 anaphylaxis cases per million doses administered). The etiology of anaphylaxis in these cases is not fully understood and is an area of active research. The overall incidence of anaphylaxis to COVID-19 mRNA vaccines is very low. By following recommendations from the US Centers for Disease Control and Prevention, an overwhelming majority of the US population can be safely immunized.