The FDA has recently granted emergency use authorization for two Covid-19 vaccines. One is from Pfizer-BioN Tech and the other from Moderna. Both vaccines have shown a very high level of effectiveness (95%) as well as safety. Allergic reactions to these vaccines are extremely rare but several have occurred.
The most likely causative agent is polyethylene glycol (PEG), a stabilizing agent that has been used in both vaccines. PEG, as well as a related compound polysorbate, can be found in certain medications as well as foods.
The CDC has issued guidance on Covid-19 vaccines and severe allergic reactions. Most individuals can, and should, be able to receive the vaccine. People with allergies to foods, medications, aeroallergens, insect stings, and latex are not at an increased risk of reacting to the vaccine. Immunocompromised patients can also receive the vaccine. They should be informed that they may have a diminished immune response.
The Covid-19 vaccine should not be administered to individuals with a known history of a severe allergic reaction to any component of the vaccine. Therefore, individuals with any history of allergy to polyethylene glycol or polysorbate should not receive the vaccine. Someone who has a severe allergic reaction to the first dose of the Covid-19 vaccine should not receive a second dose.
All patients should receive the Covid-19 vaccine in a setting where anaphylaxis can be treated. There should be a 15-30 minute observation period based on the patient history and discussion with the clinician. A thirty minute observation is recommended for a person who has had anaphylaxis to an injectable medicine without PEG or polysorbate, anaphylaxis to prior vaccines without PEG or polysorbate, anaphylaxis to food, venom, or latex, and idiopathic anaphylaxis
Feel free to contact us at 208-378-0080 with any questions regarding the Covid-19 vaccines.