COVID-19 Vaccination Sites Must Prepare for Rare Anaphylaxis Responses
Severe allergic reactions to COVID-19 vaccination are quite rare, but that doesn’t mean that pharmacies and other vaccination sites don’t have to be prepared for them. Public health officials detail what precautions and medications should be in place to deal with patients who suffer anaphylaxis and other severe adverse effects after their shot. Here are more details.
ATLANTA – Public health officials are emphasizing that vaccination locations, whether pharmacies or elsewhere, should be prepared for anaphylaxis reactions to COVID-19 vaccines.
A report in the Morbidity & Mortality Weekly Report advises that, based on early safety monitoring of the Pfizer-BioNTech COVID-19 vaccine, 21 cases of anaphylaxis were identified after administration of 1,893,360 first doses -- 11.1 cases per million vaccine doses administered. on U.S. data for December 14–23, 2020.
The national Centers for Disease Control and Prevention says similar data will be released later on the Moderna vaccine, which received emergency use authorization later.
The CDC also reports that most (86%) of the anaphylaxis cases had symptom onset within 30 minutes of vaccination, and most of those with anaphylaxis (81%) had a history of allergies or allergic reactions, including some with previous anaphylaxis events. In fact, the authors advise, up to 30% of the general U.S. population might have some type of allergy or history of allergic reactions.
Because of that, the agency recommends that vaccine providers should:
- ensure that necessary supplies are available to manage anaphylaxis, especially sufficient quantities of epinephrine in prefilled syringes or autoinjectors;
- screen potential vaccine recipients to identify persons with contraindications and precautions;
- implement recommended postvaccination observation periods, either 15 or 30 minutes depending on each patient’s previous history of allergic reactions;
- ensure that health care providers can recognize the signs and symptoms of anaphylaxis early and immediately treat suspected anaphylaxis with intramuscular epinephrine. (Because of the acute, life-threating nature of anaphylaxis, there are no contraindications to epinephrine administration);
- make sure that patients experiencing anaphylaxis are transported to facilities where they can receive appropriate medical care and instruct all patients to seek immediate medical care if they develop signs or symptoms of an allergic reaction after their observation period ends and they have left the vaccination location.
The CDC adds that healthcare providers can play an important role in vaccine safety by being vigilant in recognizing and reporting adverse events after immunization to the Vaccine Adverse Event Reporting System.
Nonanaphylaxis allergic reactions after Pfizer-BioNTech COVID-19 vaccination with symptom onset within the 0–1-day risk window include pruritus, rash, itchy and scratchy sensations in the throat and mild respiratory symptoms. The median patient age was 43 years (range = 18–65 years), and 75 (90%) reported reactions occurred in women. The median interval from vaccine receipt to symptom onset was 12 minutes (range = <1 minute–20 hours); in 61 (85%) cases, onset occurred within 30 minutes, in 11 cases, onset occurred after 30 minutes, and for 11 cases, time of onset was missing. For 56 (67%) case reports, a past history of allergies or allergic reactions was documented.
The report notes that the high rate of anaphylaxis cases after receipt of Pfizer-BioNTech COVID-19 vaccine in women might be at least partly related to their higher rate of receiving it; , although 64% of the vaccine doses administered with sex of recipient recorded were given in women.
While the data came from VAERS, researchers suggest “it is possible that intense media attention around the national COVID-19 vaccination program and heightened awareness of reports of anaphylaxis have affected vaccine recipient and health care provider behavior and practices, including elevated concern and anxiety, higher index of suspicion for anaphylaxis, and lower threshold for early treatment of suspected cases, thereby resulting in an increase in diagnosis of suspected anaphylaxis and corresponding stimulated above-baseline reporting to VAERS.”
The study also raises the possibility that the, if anaphylaxis cases after receipt of COVID-19 vaccine are identified and reported faster than vaccine doses administered are reported, the anaphylaxis rate associated with vaccination might be overestimated.
“Mortality from COVID-19 in populations at high risk is substantial and treatment options are limited. Widespread vaccination against COVID-19 with highly effective vaccines represents an important tool in efforts to control the pandemic,” the authors conclude. “CDC and FDA will continue to monitor for adverse events, including anaphylaxis, after receipt of COVID-19 vaccines and will regularly assess the benefits and risks of vaccination in the context of the evolving epidemiology of the pandemic.”