Is the COVID Vaccine Safe for People With Allergies?
We asked an immunologist to weigh in.by Sarah Ellis Health Writer
After a truly chaotic 2020, the COVID vaccines are giving us hope for a better new year. Since they were first approved by the Food and Drug Administration (FDA) in early to mid-December, Pfizer and Moderna’s vaccines have been administered to millions of Americans, primarily healthcare workers and those at highest risk of serious infection.
For the most part, vaccinations have gone down smoothly with minimal side effects. But a small number of people have reported anaphylaxis, or a severe adverse reaction to the shot, leading to fear among people with allergies about whether the vaccine is safe for them. On January 6, the Centers for Disease Control and Prevention (CDC) reported 21 confirmed cases of anaphylaxis after receipt of the Pfizer vaccine—17 of which occurred in people with a documented history of severe allergic reactions (though we don’t yet know what specifically they were allergic to). All of those patients recovered. The CDC has yet to confirm the number of reactions to the Moderna vaccine.
For now, where does that leave you? Should people with a history of allergic reactions still get the shot? The CDC says yes, unless you are allergic to one specific vaccine ingredient: polyethylene glycol. It’s a compound found in these vaccines and other medications that causes a rare allergic reaction in a very small number of people.
We asked allergist and immunologist Purvi Parikh, M.D., a spokesperson for the Allergy & Asthma Network and co-investigator for the COVID-19 vaccine trials, to share her thoughts on COVID vaccine safety for folks worried about allergic reactions. Here’s what she has to say (hint: it will probably help calm your fears).
HeanthCentral: What is in the COVID vaccines? Are there any ingredients people should be concerned about?
Purvi Parikh, M.D.: Among the two vaccines that are approved for use, one ingredient is polyethylene glycol. We don’t know for sure if this is the main culprit causing a reaction, but this is what we think it may be. The other ingredients are basically sugars, fats, and salts, which are things that people eat on an everyday basis and have in their bodies naturally.
That being said, an allergy to polyethylene glycol is pretty rare. Having an actual vaccine allergy is also very rare. We did a big study on this in one of our national allergy and immunology journals, and we found that it’s more likely that you’ll be struck by lightning than have a life-threating anaphylactic reaction to a vaccine. The worry is pretty low—the odds are 1.3 out of a million that you’ll have a true life-threatening allergic reaction. Just to give people peace of mind.
HC: What about people with other types of severe allergies to food or environmental factors—should they get the COVID shot?
PP: If you are allergic to an ingredient in the vaccine such as the polyethylene glycol, then we say you should avoid it. But if you aren’t allergic to any of those ingredients and you have other allergies—let’s say food, medication, or environmental factors—there’s no need to avoid the vaccine. We recommend that you get it because COVID-19 is far more dangerous. A main recommendation for people with allergies is that they get it at a medical facility that is equipped to treat anaphylaxis and allergic reactions, and that they wait for 30 minutes after getting the vaccine before going home, which is a little longer than the 15 minutes we ask the general public to wait.
HC: Does one vaccine (Pfizer or Moderna) appear to have caused more allergic reactions that the other?
PP: Moderna received FDA approval a week or two after Pfizer did, so it’s difficult to know for sure. Reactions to Pfizer seemed more prominent initially because that was what everyone was getting first. Then Moderna rolled out, and now we are hearing some cases from Moderna as well. I can’t really say if one is more common than the other. But both have pretty much the exact same ingredients, so just from a logical standpoint, the number of reactions should be fairly equivalent between the two.
HC: If someone is worried about whether their existing allergies might trigger a reaction to the COVID vaccine, who should they talk to about this?
PP: I recommend they talk with their allergist, first and foremost. They are the experts in the field. Again, we are encouraging those with allergies to get the vaccine unless they are allergic to a specific ingredient in one of these two vaccines. Thousands of people with allergies have already received the vaccine with no issue, even in the clinical trials.
Because these allergic reactions are so rare, people should not be afraid to get the vaccine. In fact, they should be more afraid of getting COVID-19 than any potential allergic reaction. The virus is far more common and deadly at this point.
- CDC Report of Allergic Reactions: Centers for Disease Control & Prevention. (2021). “Allergic Reactions Including Anaphylaxis After Receipt of the First Dose of Pfizer-BioNTech COVID-19 Vaccine — United States, December 14–23, 2020.” cdc.gov/mmwr/volumes/70/wr/mm7002e1.htm
- CDC Guidance on Allergic Reactions: Centers for Disease Control & Prevention. (2020). “COVID-19 Vaccines and Allergic Reactions.” cdc.gov/coronavirus/2019-ncov/vaccines/safety/allergic-reaction.html