Of the first 1.9 million doses of Pfizer’s COVID-19 vaccine administered in the United States, there were 21 cases of severe allergic reactions to the vaccine, the Centers for Disease Control and Prevention reported on Jan. 6.
The rate of anaphylaxis seen so far – 11.1 cases per million doses of vaccine – is higher than that of the flu vaccine, which is 1.3 cases per million doses, said Nancy Messonnier, director of the Center National Immunization and Respiratory Diseases of the CDC. an informative report of 6 January. But reactions to COVID-19 vaccines are "still very rare," he said.
“They are safe and effective vaccines. We have good data to prove it, "Messonnier said. Vaccine side effects monitoring systems in the country are" incredibly robust, "he said, and" the only thing we've seen is these severe allergic reactions. "
Still, sites that administer COVID-19 vaccines need to be able to recognize signs of anaphylaxis, which, if it occurs, would most likely occur shortly after vaccination, and be prepared to treat it, CDC officials said. And people who have a history of anaphylaxis, as a result, should be observed for 30 minutes after receiving the COVID-19 vaccine.
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Anaphylaxis, which can be life-threatening, requires emergency treatment with epinephrine. The UK, which began immunizing its population against COVID-19 with the Pfizer vaccine on December 8, was the first country to report cases of severe allergic reaction after vaccines (SN: 12/11/20).
The CDC reported 21 cases in the United States, covering vaccines administered Dec. 14-23, in a study of the report on morbidity and mortality published online Jan. 6. These first vaccinations were only with the Pfizer vaccine. Officials still do not know what is causing the allergic reaction after immunization with the vaccine.
In the study there were no deaths from anaphylaxis. Nineteen of the 21 people were treated with epinephrine and four were hospitalized. Seven of the people in the report had experienced anaphylaxis in the past. CDC officials recommend that people with a history of anaphylaxis alert the person administering the shot before doing so.
The CDC continues to monitor these reactions. Since the report’s data was analyzed, the total number of reactions reported in the United States has grown slightly to 29 cases. Some of them were linked to vaccination with the Modern COVID-19 vaccine, the agency reported in the briefing.