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.