Allergic Reactions to Covid19 (Sars-Cov-2) Vaccine

Abstract

1. Background The recent approval of various covid vaccines will result in massive immunization of the public with these vaccines. Cases of allergic reactions such as rashes, urticaria, anaphylaxis have been reported worldwide. The following is a summary, from an allergist’s perspective, of the components found to be present in situations where the patient has experienced an allergic reaction to the Covid 19 vaccine. The FDA granted an Emergency Use Authorization of the Pfizer-BioNTech COVID-19 vaccine on December 11, 2020 and the Moderna vaccine on December 18, 2020. The Covid19 vaccine (BNT 162b2) from PfizerBioNTech pharmaceuticals contains various excipients. Among these, there is one excipient with the ability to cause allergic reactions, ALC -0159, since it contains polyethylene glycol (PEG) or macrogol. After immunization with this vaccine, reports of reactions occurred during December 2020 in Alaska at Fairbanks Memorial Hospital. The reaction was a systemic, anaphylactic type and treated with epinephrine, corticoids and antihistamines. Reports of reactions to the vaccine have also occurred in England and Spain. Dr June Raine, Chief Executive of the Medicines and Healthcare products Regulatory Agency in the UK, made the following statement to vaccination centers regarding COVID-19 vaccination with the Pfizer/BioNTech vaccine: “Any person with a history of anaphylaxis to a vaccine, medicine or food should not receive the Pfizer/BioNTech vaccine. A second dose should not be given to anyone who has experienced anaphylaxis following administration of the first dose of this vaccine. CDC considers a history of the following to be a contradiction to vaccination with both the Pfizer BioNTech and Moderna COVID-19 vaccine: Severe allergic reaction (eg anaphylaxis) after a previous does of an mRNA COVID-19 vaccine or any of its components. Immediate allergic reaction of any severity to a previous dose of an mRNA COVID-19 vaccine or any of its components (including polyethylene glycol (PEG]). Immediate allergic reaction of any severity to polysorbate (due to potential cross-reactive hypersensitivity with the vaccine ingredient PEG). These persons should not receive mRNA COVID-19 vaccination at this time unless they have been evaluated by an allergist-immunologist and it is determined that the person can safely receive the vaccine (eg under observation, in a setting with advanced medical care available). The ACAAI (American College of Allergy Asthma and Immunology) on Dec 21st 2020 stated that reactions to vaccines, in general, are rare with the incidence of anaphylaxis estimated at 1.31 in 1 million doses given. Nevertheless, the ACAAI’s COVID-19 Vaccine Task Force recommends the following guidance for physicians and other providers related to risk of an allergic reaction on vaccination. 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 IM epinephrine as the first line treatment.