UPDATED: March 11, 2021

The American College of Allergy, Asthma and Immunology (ACAAI) COVID-19 Vaccine Task Force continues to closely monitor information from sources reporting on allergic reactions to the COVID-19 vaccines. As such, ACAAI has updated its guidance to reflect the most recent recommendations from the CDC and the FDA.

Reactions to vaccines, in general, are rare with the occurrence of anaphylaxis estimated at 1.31 in 1 million doses given. Subsequent to the FDA emergency use authorization of the mRNA-based Pfizer-BioNTech COVID-19 vaccine on Dec. 11, 2020, and the Moderna vaccine on Dec. 18, 2020, anaphylaxis rates as of Jan. 29, 2021 are reported by the CDC to be five per million with Pfizer-BioNTech and 2.5 per million with Moderna. The anaphylaxis rate for the Johnson & Johnson COVID-19 vaccine has not been reported.

The ACAAI COVID-19 Vaccine Task Force recommends the following guidance related to risk of an allergic reaction on vaccination.

These recommendations are based on best knowledge to date but could change at any time, pending new information and further guidance from the FDA, CDC.

1. Anyone receiving the vaccine should be screened to determine possible risk of an allergic reaction to the mRNA (Moderna and Pfizer) and adenovirus vector (Johnson & Johnson) COVID-19 vaccines. You should be asked if you have a history of a severe allergic reaction to any prior vaccine. If the answer is yes, you should be referred to a board-certified allergist/immunologist for further evaluation prior to COVID-19 vaccination.
2. According to the CDC, if you have had a severe or an immediate allergic reaction of any severity within 4 hours after getting the first COVID-19 shot, you should not get the second shot. Additionally, patients who experience a severe or an immediate allergic reaction of any severity (hives, swelling, wheezing) or who have questions related to risk of an allergic reaction, may be referred to a local board-certified allergist/immunologist to provide more care or advice.
3. The COVID-19 vaccines should be administered in a health care setting where anaphylaxis can be treated. All individuals must be observed for at least 15-30 minutes after injection to monitor for any adverse reaction. All anaphylactic reactions should be managed immediately with epinephrine as the first line treatment. Most anaphylactic reactions have occurred within 15 minutes.
4. The mRNA and adenovirus vector COVID-19 vaccines should not be administered to individuals with a known history of a severe allergic reaction to any component of a particular vaccine. Although the specific vaccine component causing the anaphylaxis has not been identified, polyethylene glycol (PEG) is one of the ingredients in the mRNA vaccines and has been known to cause anaphylaxis. Polysorbate 80 is an ingredient in the Johnson & Johnson vaccine which may cause anaphylaxis and may cross-react with PEG.

Patients with allergic reactions to PEG should not be immunized with the mRNA COVID-19 vaccines. Consideration may be given to vaccination with adenovirus vector COVID-19 vaccine.

The CDC recommends that the adenovirus vector vaccine may be an option instead of a second dose of an mRNA vaccine for patients who had an adverse reaction to the mRNA product. People who have received one mRNA COVID-19 vaccine dose but for whom the second dose is contraindicated should wait at least 28 days after the mRNA vaccine dose to receive the adenovirus vector COVID-19 vaccine. These patients should have the vaccine in a setting able to treat anaphylaxis and observed a minimum of 30 minutes after the injection.

In patients with a contraindication to adenovirus vector COVID-19 vaccine (including due to a known polysorbate allergy), there should be consideration of administering the mRNA COVID-19 vaccination.

Per CDC guidance, polysorbate allergy is no longer a contraindication to mRNA COVID-19 vaccination, it is a precaution. However, because of potential cross-reactive hypersensitivity between ingredients in mRNA and adenovirus vector COVID-19 vaccines, consultation with an allergist-immunologist should be considered to help determine if the patient can safely receive vaccination. If the mRNA vaccine is given in a patient with polysorbate allergy, it should be done in a setting able to treat anaphylaxis and the patient observed a minimum of 30 minutes after the injection.

1. Data regarding risk in individuals with a history of allergic reactions related to mast cell activation syndrome/idiopathic anaphylaxis is very limited and evolving. A decision to receive COVID-19 vaccines should be undertaken by you with your physician or other provider administering the vaccine using their professional judgment balancing the benefits and risks associated with taking the vaccine.
2. People with common allergies to medications, foods, inhalants, insects, and latex are probably no more likely than the general public to have an allergic reaction to the mRNA COVID-19 vaccines. Those patients should be informed of the benefits of the vaccine versus its risks.
3. The mRNA and adenovirus vector COVID-19 vaccines are not live vaccines and can be administered to immunocompromised patients. Physicians and other providers should inform immunocompromised patients of the possibility of a diminished immune response to the vaccines.
4. Infrequently, people who have received dermal fillers may develop swelling at or near the site of filler injection (usually face or lips) following administration of a dose of an mRNA COVID-19 vaccine. This appears to be temporary and can resolve with medical treatment, including corticosteroid therapy. mRNA and adenovirus vector COVID-19 vaccines may be administered to people who have received injectable dermal fillers who have no contraindications to vaccination. No additional precautions are needed. However, these people should be advised to contact their health care provider for evaluation if they develop swelling at or near the site of dermal filler following vaccination.
5. If you are receiving the mRNA COVID vaccine, you should expect local (e.g., pain, swelling, skin rash at the injection site, some swelling of the lymph nodes on the same side as the vaccinated arm) and systemic (e.g., fever, fatigue, headache, chills, muscle pain, joint pain, or inflammation) post-vaccination symptoms. These are expected side effects, not allergic reactions. They usually resolve within a few days.

January 8, 2021

The American College of Allergy, Asthma and Immunology (ACAAI) COVID-19 Vaccine Task Force is closely monitoring information from sources reporting on allergic reactions to the mRNA COVID-19 vaccines. As such, ACAAI has updated its guidance to reflect the most recent recommendations from the CDC and the FDA. In addition, the Task Force recommends certain questions regarding past vaccine reactions to be asked of everyone receiving a vaccine.

With the FDA emergency use authorization of the Pfizer-BioNTech COVID-19 vaccine on Dec. 11, 2020, and the Moderna vaccine on Dec. 18, 2020, the ACAAI COVID-19 Vaccine Task Force recommends the following guidance for physicians and other providers related to risk of an allergic reaction on vaccination.

These recommendations are based on best knowledge to date but could change at any time, pending new information and further guidance from the FDA, CDC or other experts.

1. Anyone receiving the vaccine should be screened to determine possible risk of an allergic reaction to the mRNA COVID-19 vaccines. You should be asked if you have a history of a severe allergic reaction to any prior vaccine. If the answer is yes, you should be referred to a board-certified allergist/immunologist for further evaluation prior to COVID-19 vaccination.

2. According to the CDC, if you have had a severe or an immediate allergic reaction of any severity within 4 hours after getting the first COVID-19 shot, you should not get the second shot. Additionally, patients who experience a severe or an immediate allergic reaction of any severity (hives, swelling, wheezing) or who have questions related to risk of an allergic reaction, may be referred to a local board-certified allergist/immunologist to provide more care or advice.

3. The mRNA COVID-19 vaccines should be administered in a health care setting where anaphylaxis can be treated. All individuals must be observed for at least 15-30 minutes after injection to monitor for any adverse reaction. All anaphylactic reactions should be managed immediately with epinephrine as the first line treatment. The majority of anaphylactic reactions have occurred within 15 minutes.

4. The mRNA COVID-19 vaccines should not be administered to individuals with a known history of a severe allergic reaction to any component of the vaccine. Although the specific vaccine component causing the anaphylaxis has not been identified, polyethylene glycol (PEG) is one of the ingredients and has been known to cause anaphylaxis. Since polysorbate, a substance found in medications and foods, can cross-react with PEG, patients with allergic reactions to polysorbate should not be immunized with the mRNA vaccines.

5. Data regarding risk in individuals with a history of allergic reactions related to mast cell activation syndrome/idiopathic anaphylaxis is very limited and evolving. A decision to receive either of the mRNA COVID-19 vaccines should be undertaken by you with your physician or other provider administering the vaccine using their professional judgment balancing the benefits and risks associated with taking the vaccine.

6. People with common allergies to medications, foods, inhalants, insects, and latex are probably no more likely than the general public to have an allergic reaction to the mRNA COVID-19 vaccines. Those patients should be informed of the benefits of the vaccine versus its risks.

7. The mRNA COVID-19 vaccines are not live vaccines and can be administered to immunocompromised patients. Physicians and other providers should inform such immunocompromised patients of the possibility of a diminished immune response to the vaccines.

8. If you are receiving the mRNA COVID vaccine, you should expect local (e.g., pain, swelling, skin rash at the injection site, some swelling of the lymph nodes on the same side as the vaccinated arm) and systemic (e.g., fever, fatigue, headache, chills, muscle pain, joint pain, or inflammation) post-vaccination symptoms. These are expected side effects, not allergic reactions. They usually resolve within a few days.

References

McNeil MM, Weintraub ES, Duffy J, et al. Risk of anaphylaxis after vaccination in children and adults. J Allergy Clin Immunol. 2016;137(3):868-878.

Dreskin et al. International Consensus (ICON): allergic reactions to vaccines World Allergy Organization Journal (2016) 9:32.

Wylon, K., Dölle, S. & Worm, M. Polyethylene glycol as a cause of anaphylaxis. Allergy Asthma Clin Immunol 12, 67 (2016).

Stone CA, Liu Y, et al. Immediate Hypersensitivity to Polyethylene Glycols and Polysorbates: More Common Than We Have Recognized. J Allergy Clin Immunol Pract. 2019; 7(5): 1533–1540.