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

Although rare, the rate of anaphylaxis after COVID-19 mRNA vaccines has been found to be about 10 times higher than that documented for influenza vaccines, CDC officials said Wednesday.

Overall, 21 cases of anaphylaxis after COVID vaccination have been reported in approximately 1.9 million doses since December 23, according to an early study. Weekly report on morbidity and mortality release. This amounts to 11.1 cases per million compared to about 1.3 cases per million after the inactivated flu vaccine, agency officials said in a media call.

They mentioned that, as of now, 29 confirmed cases of anaphylaxis are reported with Pfizer / BioNTech and Moderna vaccines. In addition, officials said, MMWR the December 14-23 report focuses on the Pfizer vaccine because the Moderna vaccine was not available until December 21st. However, there are not enough data to see a difference in risk between vaccines.

To date, no deaths from anaphylaxis have been observed.

Nancy Messonnier, MD, director of the CDC’s National Center for Immunization and Respiratory Disease, stressed that these events are rare and that the benefits of COVID-19 vaccination outweigh the risks. Moreover, comparing them with flu figures “doesn’t make sense” when there are more than 2,000 deaths caused by COVID-19 every day in the US

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

Of the 21 cases examined in MMWR, 18 have documented allergies or allergic reactions to drugs, medical products, food or insect bites, and seven have experienced anaphylaxis in the past, including one from a rabies vaccine and one from an influenza A (H1N1) vaccine.

Messonnier acknowledged the millions of people who have allergies to food or insect bites and pointed to the difference between “someone who had a mild allergic reaction in childhood to someone with a severe allergic reaction next week.”

“A lot of people have a certain history of bee sting or food allergy and the fact that people in this group have had anaphylaxis … may not mean that allergic reactions put them at a higher risk, but it could.” , she added.

Messonnier noted that the CDC’s guidelines indicate that anyone with a history of anaphylaxis, for any reason, should talk to their healthcare provider before vaccination, and doctors should exercise judgment.

CDC officials said anyone with a history of anaphylaxis receiving the vaccine should be seen for 30 minutes afterwards, as people who have previously had anaphylaxis are at risk of doing so.

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

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

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

Nineteen patients were treated with epinephrine, 17 were treated in the emergency department and four were hospitalized, including three in intensive care. Of the 20 with information available, all were discharged at home.

Messonnier also briefed on the reports of health workers who choose not to get vaccinated, saying she is “certainly concerned” about this.

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