CDC reports on allergic reactions to COVID-19 vaccines

The Centers for Disease Control and Prevention today reported 21 cases of anaphylaxis, a life-threatening allergic reaction, among the nearly 1.9 million people who received a first dose of the Pfizer COVID-19 vaccine between Dec. 14 and 23. That’s an estimated 11.1 cases per 1 million doses. While higher than the 1.3 cases per 1 million doses associated with flu vaccine, “I want to assure you that this is still a rare outcome,” said Nancy Messonnier, M.D., director of CDC’s National Center for Immunization and Respiratory Diseases.

About 71% of the 21 cases associated with the Pfizer COVID-19 vaccine occurred within 15 minutes of vaccination. Seventeen of the individuals had a documented history of allergies or allergic reactions, and all but two cases were treated with epinephrine. Four patients were hospitalized, 17 were treated in an emergency department and all recovered, officials said.

One case of anaphylaxis was reported among more than 224,000 people who received a first dose of the Moderna COVID-19 vaccine over the same period, the report notes. Confirmed anaphylaxis cases for both vaccines currently total 29, officials said. CDC plans to release more information as it becomes available.

“Locations administering COVID-19 vaccines should adhere to CDC guidance for use of COVID-19 vaccines, including screening recipients for contraindications and precautions, having the necessary supplies available to manage anaphylaxis, implementing the recommended post-vaccination observation periods, and immediately treating suspected cases of anaphylaxis with intramuscular injection of epinephrine,” the report notes.