CDC: Anaphylaxis with Pfizer-BioNTech COVID-19 Vaccine “Exceedingly Rare”
Twenty-one cases of anaphylaxis occurred with the first 1.9 million doses of the Pfizer-BioNTech mRNA COVID-19 vaccine, according to data in MMWR.
This equates to a rate of 11.1 cases per 1 million doses. In comparison, the anaphylaxis rate with influenza vaccination is 1.3 per million. At a news briefing on Wednesday, Dr. Nancy Messonnier, director of the CDC’s National Center for Immunization and Respiratory Diseases, said the anaphylaxis rate with the COVID-19 vaccine is “still exceedingly rare” and emphasized that “the known and potential benefits of the current COVID-19 vaccines outweigh the known and potential risks.” She noted that the U.S. is seeing roughly 2000 COVID-19 deaths per day and called the vaccines “a good value proposition.”
Seventeen of the 21 anaphylaxis cases reported through Dec. 23 occurred in people with a known history of allergies or allergic reactions (e.g., to medications, foods, or insect stings), including seven with prior anaphylactic reactions. Anaphylaxis occurred at a median of 13 minutes after COVID-19 vaccination. Follow-up data were available for 20 of the patients, all of whom recovered (usually following epinephrine administration).
No geographic clusters of anaphylaxis were observed. Additionally, reactions occurred with doses from multiple vaccine lots.
At the briefing, CDC officials noted that another eight cases of anaphylaxis have been reported since Dec. 23. Updated information, including anaphylaxis rates with Moderna’s vaccine, is forthcoming.