As COVID-19 vaccination efforts are intensely spreading across the United States, public health officials in the country confirm that severe allergic reactions to the Pfizer-BioNTech COVID-19 vaccine are rare.
In a study published Jan. 6 by the U.S. Centers for Disease Control and Prevention (CDC), researchers found that the risk of anaphylaxis (a serious and life-threatening allergic reaction) to the vaccine is extremely low. . Based on data from people who have received the first of the two recommended doses, only one in 90,000 people will experience, on average, this adverse reaction. This accounts for less than 3 percent of the risk of dying from suffocating food for life.
Technically, the possibility of severe allergic reactions to the Pfizer-BioNTech vaccine is approximately 8.5 times higher than the risk of the seasonal flu vaccine, which has a rate of approximately one in 769,000. But experts point out that it is still a small number: according to the study, 1.89 million people in the US received the first dose of the vaccine between December 14 and 23 and more than 99.998% of them did not go. experience anaphylaxis.
The news should help people who have concerns about getting the vaccine. According to one National Geographic-Morning Consult poll conducted in December, seven out of ten Americans say they are wary of the possible side effects of any COVID-19 vaccine, with 58% of respondents saying they will be vaccinated, but until they have seen how it affects the except other people.
However, overall, the data reveal that the risk of anaphylaxis is much lower than the negative results associated with COVID-19 infections, especially among older Americans. By October 2020, the disease had become one of the leading causes of death in the United States among people over the age of 45, overcoming car crashes, suicide, homicide, and accidental overdose of drugs. So far, the pandemic has killed more than one in 1,000 Americans.
“My colleagues at CDC and FDA and I are committed to ensuring that COVID-19 vaccines are safe,” Nancy Messonnier, director of the CDC National Center for Vaccination and Respiratory Diseases, said at a news conference Wednesday. about the study. “I know I look forward to the day I can roll up my sleeves and get vaccinated.”
What do we know about cases of anaphylaxis?
Of the 21 cases of severe anaphylaxis associated with the Pfizer-BioNTech vaccine, 19 occurred in women and half were in people between 40 and 60 years of age (the other half were between 27 and 40 years old). Seventeen of the cases were in people with a history of allergic reactions to food, medication, other types of vaccines, or bee and wasp stings. Seven had a past history with anaphylaxis.
In 18 of the 21 documented cases, patients began to show symptoms of anaphylaxis 30 minutes after receiving the dose. Almost all were treated immediately with epinephrine, a common treatment for anaphylaxis and the active ingredient in an Epi-Pen. Only four patients needed hospitalization. At least 20 of the 21 patients had fully recovered by December 23 or had been discharged from the hospital by then.
There is no geographical grouping of cases and they go back to different batches of the vaccine, so there is no evidence that vaccine contamination was a problem. The investigation of the cases is still early and the deviation towards women may speak of a genuine biological phenomenon, or it may reflect the fact that more women than men — 62% of the 1.89 million — received the vaccine during the period. of study.
Is there a clear difference in risk between the Pfizer-BioNTech and Moderna vaccines?
Currently, no. Overall, the Pfizer-BioNTech vaccine arose more cases than the Modern vaccine, but CDC officials say it is likely because the Pfizer-BioNTech version was first authorized and therefore given to more people during the period. of study.
In total, 1,893,360 doses of the Pfizer-BioNTech vaccine were administered during the study period, approximately 8.5 times more than the 224,322 Modern doses administered in that same period. In addition, the launch of the Moderna vaccine did not begin until the last three days of the study period, on December 21st. Of these doses of Moderna, only one case of anaphylaxis was reported to the CDC and more data is expected.
Should I get the vaccine?
In the briefing, Messonnier and Tom Clark, the leader of the CDC’s vaccine evaluation team, stressed that, in general, when people are advised to get the vaccine, they should take it.
To ensure a rapid response in the event of a rare allergic reaction, people should be observed for 15 minutes after receiving the vaccine. People with a history of anaphylaxis or immediate allergic reactions should be monitored for 30 minutes.
Clark outlined two specific examples of people who should not get the full two-dose Pfizer-BioNTech vaccine regimen: “If you have an immediate reaction to the first [COVID-19 vaccine] dose, do not take a second, and if you have a known allergy to the vaccine components or related compounds, we recommend that you do not get vaccinated at this time. “People who do not know if they may be allergic to a vaccine ingredient of the vaccine should talk to your doctors before vaccination.
Specifically, the CDC warns that COVID-19 vaccines that use messenger RNA (mRNA), including Pfizer BioNTech and Moderna vaccines, also contain polyethylene glycol to protect mRNA, so people with allergies to the compound should not to receive the vaccine. Similarly, people allergic to polysorbates (which are chemically similar to polyethylene glycol) should not receive the shot at this time.
In general, the CDC recommends that people with allergy problems consult their health care providers.
“There’s a big difference between someone who had a mild allergic reaction during their childhood, and someone who had a severe allergic reaction last week,” Messionner said. “It will be very important for a doctor to help a patient exercise his judgment.”