CDC: Anaphylaxis rate with COVID Vax 10 times higher than with flu shots

Although rare, the rate of anaphylaxis after COVID-19 mRNA vaccines has appeared about 10 times that documented for influenza vaccines, CDC officials said on Wednesday.

A total of 21 cases of anaphylaxis following COVID vaccination have been reported out of approximately 1.9 million doses administered as of December 23, according to a first Morbidity and Mortality Weekly Report Release. That’s 11.1 cases per million compared to about 1.3 cases per million from an inactivated influenza vaccine, agency officials said on a media call.

They noted that to date, 29 confirmed cases of anaphylaxis have been reported with the Pfizer / BioNTech and Moderna vaccines. In addition, officials said, the MMWR The December 14-23 report focuses on the Pfizer vaccine, since the Moderna vaccine was not available until December 21. Yet, there is not enough data to see a difference in risk between vaccines.

No death from anaphylaxis has been observed to date.

Nancy Messonnier, MD, director of the CDC’s National Center for Immunization and Respiratory Disease, pointed out that these events were rare and that the benefits of COVID-19 vaccination outweighed the risks. Moreover, comparing them to the flu numbers, “misses the point” when there are more than 2,000 deaths from COVID-19 every day in the United States.

“It’s always a good value proposition,” she says. “Even though the rate is higher than what we see after routine immunizations, anaphylaxis is still rare.”

Of the 21 cases examined MMWR, 18 had allergies or documented allergic reactions to drugs, medical products, food or insect bites, and seven had previously suffered from anaphylaxis, including one following a rabies vaccine and one following a vaccine against influenza A (H1N1).

Messonnier recognized the millions of people who have allergies to food or insect stings, and pointed out the difference between “someone who had a mild allergic reaction as a child and someone with a severe allergic reaction.” next week”.

“Many people have a history of allergy to bee stings or to food and just because people in this group have anaphylaxis … doesn’t necessarily mean that allergic reactions put them at a higher risk. , but it could, ”she added.

Messonnier noted that CDC guidelines state that anyone with a history of anaphylaxis for any reason should speak to their health care provider before vaccination and that clinicians should exercise their judgment.

CDC officials said anyone with a history of anaphylaxis and receiving the vaccine should be observed for 30 minutes afterward, as people who have had anaphylaxis in the past are at risk of having it again.

The agency recently updated its interim guidelines for clinicians on vaccine contraindications, adding that people with an immediate allergic reaction to the first vaccine should not receive a second dose.

Seventeen of the 21 cases were among those with a history of anaphylaxis, and the median time from vaccination to onset of symptoms was 13 minutes, although about 70% of patients had symptoms within 15 minutes . The median age of the patients was 40 years and 19 were female.

the MMWR report noted that the female predominance had been observed earlier for immediate hypersensitivity reactions to the influenza A (H1N1) vaccine. But the disproportion with the COVID vaccination could simply be due to the fact that more women than men receive the Pfizer / BioNTech vaccine, the authors said.

Nineteen patients were treated with epinephrine, 17 were treated in the emergency room and four were hospitalized, three of them in intensive care. Of the 20 for which information was available, all were sent home.

Additionally, Messonnier briefly addressed reports of health workers choosing not to be vaccinated, saying she was “definitely concerned” about it.

“It is extremely important that we provide the correct information to health workers and that we quickly dispense with misinformation,” she said. “We need them not only to protect themselves but also to educate their patients so that everyone understands these vaccines … have a good safety profile, they work and they … can help us end to this pandemic. “