A: If you have had an allergic reaction to any ingredient included in the Pfizer or Moderna vaccines, then you should not get this type of COVID-19 vaccine. If you have an allergic reaction to the first dose of these vaccines, you should not get the second dose. If you have a history of severe allergic reactions that are not related to vaccines or injectable medications getting these or other COVID-19 vaccines is still recommended.
TL;DR While allergic reactions after COVID-19 vaccination remain rare and are treatable, the following is recommended by the United States (U.S.) Centers for Disease Control and Prevention (CDC) regarding COVID-19 vaccines currently available in the U.S:
❇️If you are allergic to polyethylene glycol (PEG) (or any of the other ingredients included in the Pfizer or Moderna vaccines), CDC recommends you don’t get these vaccines. You may, however, still be able to get the J&J/Janssen vaccine.
❇️If you had a severe or immediate allergic reaction to the first dose of the Pfizer or Moderna vaccine, CDC recommends that you do not get a second dose of these vaccines.
❇️If you have a history of severe allergic reactions to other exposures besides vaccines or injectable medications (such as food, pet, latex or other environmental allergens, or oral medications) or a family history of severe allergic reactions CDC still recommends you get a COVID-19 vaccine (but you may be monitored for an additional 15 minutes at the vaccination site).
❇️If you have had a severe or immediate allergic reaction to a different vaccine or any injectable therapy in the past, you may still be able to get a COVID-19 vaccine (with additional monitoring time)-your healthcare provider can help you determine what is safest for you.
❇️If you are allergic to polysorbate (or any of the other ingredients in the J&J/Janssen vaccine), CDC recommends you do not get this vaccine. But, you may still be able to get the Pfizer or Moderna vaccine.
What counts as an allergic reaction?
CDC defines a *severe allergic reaction* (or anaphylaxis) as one that requires someone to be treated with epinephrine or EpiPen or to have to go to the hospital. An *immediate allergic reaction* is defined as one that isn’t severe enough to require emergency care and happens within 4 hours of getting the vaccine (may include symptoms such as hives, swelling or trouble breathing).
Some people develop a red, itchy rash on their arm near the location where they got their shot, which has been referred to as “COVID arm”, and can last for several days. If you experience this after the first dose of the Pfizer or Moderna vaccine, you *can* still get the second dose, but consider getting it in the other arm.
How rare is rare and what if an allergic reaction does happen?
In January, CDC reported that severe allergic reactions were occurring at a rate of 11.1 per 1 million doses for the Pfizer vaccine and 2.5 per 1 million doses for the Moderna vaccine. A study carried out among ~65,000 employees at Massachusetts General Hospital and Brigham and Women’s Hospital who received the first dose of the Pfizer or Moderna vaccine between mid-December to mid-February found that only 2.1% had an immediate allergic reaction and 0.025% had a severe allergic reaction (anaphylaxis). All people who experienced a severe allergic reaction were treated successfully and none went into anaphylactic shock.
Luckily, not only do allergic reactions to the available COVID-19 vaccines remain rare, several safeguards are in place to assure people that do have an allergic reaction are identified quickly and get any needed treatment right away.
✅First, all people are monitored for a minimum of 15 minutes post-vaccination to watch for allergic reactions and those that have had severe allergic reactions to other things besides vaccines or had any allergic reaction to a vaccine or injectable therapy in the past, are monitored for 30 minutes.
✅Second, vaccination sites have staff, medications and equipment on hand to immediately treat anyone that might experience an allergic reaction.
✅Third, vaccine sites can rapidly call for any additional emergency medical services that might be needed.
✅Fourth, vaccine providers are reporting any allergic reactions via the Vaccine Adverse Event Reporting System (VAERS) to be tracked and monitored.
Bottom line; most people don’t need to worry about an allergic reaction after COVID-19 vaccination, but if you have a history of allergic reactions-check with your healthcare provider to see which vaccine might be best for you to get. Everyone can also rest assured that systems are in place to identify and immediately treat any people who do experience allergic reactions after vaccination.
Our previous post on vaccines and anaphylaxis
Our previous post on the ingredients in the Pfizer and Moderna vaccines
Our previous post on the ingredients in the J&J/Janssen vaccine
Our previous post on “COVID arm”
For more information on vaccines and allergies from CDC see here or see here.
More information on the study mentioned
Please note the information contained here for informational purposes and is not medical advice. Please contact your health care provider for guidance specific to your situation if you have a history of allergic reactions.
