Resource: Maintaining Safety with SARS-CoV-2 Vaccine
Source: New England Journal of Medicine
Synopsis: A review article, focused on immediate allergic responses to the 6 COVID-19 vaccines that are either under EUA or in late phase studies. Of greatest concern, the anaphylactic reaction with flush, pruritus, urticaria, angioedema, tachycardia and laryngeal edema, which is estimated to occur in approximately 1: 100,000 with the new COVID-19 vaccines. This rate is higher than the 1:1,000,000 rate typically seen with prior types of vaccines. The reported cases to date suggest an IgE-mediated process, suggesting prior sensitization to one of the components in the vaccine. Allergic reactions are primarily related to the excipients (preservatives and stabilizers) used in vaccine production, which are listed in the paper. The PEG 2000 molecule is the most likely source of allergy. This is a lipid-based nanoparticle carrier, which prevents the rapid enzymatic degradation of mRNA, prolonging the half-life of the vaccine, in both the Moderna and Pfizer-BioNTech versions of the vaccine. The authors recommend that patients with a prior history of reactions to either PEG-2000 or related polysorbate products (also used in the AstraZeneca vaccine) avoid the vaccines until more information is available.
Comment: Polyethylene glycol (PEG) is a component of the COVID-19 Vaccines. Polyethylene glycol compounds are widespread in household products from skin care and cosmetics, to baby wipes and cleaners. They are used as thickeners, softeners, moisture caring agents, penetration enhancers, and surfactants. Anyone with a known allergy to polyethylene glycol should consult their physician prior to vaccine administration.
