RISK: According to the American Centers for Disease Prevention and Control, however, no deaths were to be deplored from the Pfizer vaccine
To prevent this data from worrying, the American health authorities have reminded that the benefits of vaccination were much greater than the potential risks. One in about 100,000 people has experienced a severe allergic reaction after receiving a dose of Pfizer-BioNTech’s coronavirus vaccine, the Centers for Disease Prevention and Control (CDC) said on Wednesday.
The CDC has documented 21 cases of anaphylactic shock, a severe allergic reaction, out of a total of 1,893,360 injections of the vaccine given between December 14 and 23. “On average, this represents a rate of 11.1 anaphylactic shocks per million doses administered,” said Nancy Messonnier, a CDC official. For comparison, influenza vaccines cause about 1.3 anaphylactic shock per million doses.
Excessively rare reactions
Even though the rate for Pfizer-BioNTech’s coronavirus vaccine is about ten times higher, the number of cases of severe allergic reactions remains “exceedingly rare” and the population has every interest in being vaccinated, the risks of the pandemic of Covid-19 being much larger, insisted Nancy Messonnier. “We know how to treat anaphylactic shock and we have put in place procedures at the vaccination sites” to react if necessary, she added.
The 21 cases identified by the CDC involved people aged 27 to 60, with a median age of 40. All but two were treated with epinephrine, which is commonly used to treat severe allergies. Some 19 cases (90%) of allergic shock occurred in women and symptoms occurred between two and 150 minutes after a vaccine injection, for a median time of 13 minutes. These symptoms included rash, hives, a feeling of suffocation, swelling of the tongue, difficulty breathing, swollen lips, nausea, and a persistent dry cough.
Investigation of the causes
Four patients (19%) were hospitalized, including three in intensive care, and the other 17 were treated in an emergency department. No deaths were reported and all but one were well at the time of writing. Nancy Messonnier also indicated that investigations were underway to determine the cause of the allergic reactions.