A study by the Centers for Disease Control and Prevention released Wednesday outlined 21 cases of anaphylaxis among the first 1.9 million recipients of Pfizer Inc.’s vaccine, a rate of 11.1 per million doses administered. No anaphylaxis deaths have been reported, the CDC said.
The CDC said it has seen the reactions in recipients of the Moderna Inc. shot as well, with 29 confirmed cases of anaphylaxis to date between the two vaccines. Still, the CDC is sticking with its recommendation that most people should still get the shots, saying the risks surrounding the vaccine are less than the risk of getting a severe case of Covid-19.
“Even at 11 cases per million doses administered it is a very safe vaccine,” said Nancy Messonnier, director of the CDC’s National Center for Immunization and Respiratory Diseases. “I continue to believe that the risk of Covid, and the risk of poor outcomes, especially in senior citizens, makes it imperative that people go ahead and get vaccinated as soon as it’s available to them.”
The only exceptions outlined that the CDC has outlined are people with a known allergy to the vaccines’ ingredients, and people who had a reaction to the first dose of a Covid vaccine.
However, Messonnier stressed that those with a history of allergic reactions to drugs and severe allergic reactions from any cause should be observed for half an hour following the shots, and providers should be prepared with allergic reaction treatments like the EpiPen.
Regulators are closely tracking the safety of Covid-19 vaccines as they are rolled out, she added, noting, “we are not seeing any worrisome signals. The only thing we have seen is these serious allergic reactions.”
Established Pattern
Severe allergic reactions to vaccines are an established, though uncommon, phenomenon. They occur about 1.3 times per million doses of flu vaccine administered, and with other vaccines have been seen at rates of 12 to 25 per million doses, though the studies were small.
Many safety issues after vaccination are also coincidental, Messonnier noted, saying, “the vaccine isn’t always the cause of it.”
The severe allergic reactions observed with early Covid-19 vaccines haven’t significantly affected plans for distribution, Messonnier said.
Of patients who had severe allergic reactions to the Pfizer vaccine, four had to be hospitalized, and the rest were treated in the emergency room. CDC officials said that all 20 of the patients it had information about recovered.
“It is an unusual complication. It is reversible and treatable,” said Anthony Fauci, the government’s top infectious disease doctor, during an online event at the Economic Club of Washington DC.