The Moderna and Pfizer COVID-19 vaccines are incredibly safe and effective. Allergic reactions to these vaccines are quite rare, occurring in approximately 4.5 per million Pfizer vaccinations, and 2.5 per million Moderna vaccinations. As discussed elsewhere on this website, patients with environmental, food, insect sting, and most medication allergies are not at increased risk of reaction to these vaccines. However, patients with a history of reaction to injectable medications or previous vaccines may be at increased risk. Allergy & Asthma Care of Fairfield County is pleased to now offer skin testing for polyethylene glycol and polysorbate, which are the components of the Pfizer and Moderna vaccines thought responsible for most allergic reactions. If you feel that you may be at increased risk of a reaction to the COVID vaccine, please call to schedule an appointment at 203-259-7070.