Antibody Response to Graded Dosing of COVID-19 mRNA Vaccines After Allergic Reaction to First Dose

In December 2020, an Emergency Use Authorization was issued for Pfizer-BioNTech and Moderna COVID-19 vaccines. Shortly thereafter, allergic reactions including anaphylaxis to vaccination were described.1 Initial rates of anaphylaxis were reported at 11.1 cases per million doses administered.2 Continued safety monitoring through the Vaccine Adverse Event Reporting System since then has shown lower rates of anaphylaxis.3 While rare, systemic reactions have occurred, making administration of subsequent doses problematic in some patients, resulting in vaccine hesitancy.