Coronavirus disease 2019 (COVID-19) has infected more than 17 million individuals and caused over 300,000 deaths in the United States (US).1 The US Food and Drug Administration (FDA) has issued Emergency Use Authorizations (EUA) for COVID-19 vaccines from Pfizer-BioNTech (December 11, 2020)2 and Moderna (December 18, 2020).3
Both vaccines harness the power of nucleoside-modified messenger RNA (mRNA) technology, where intracytoplasmic mRNA translation of the viral spike protein precedes binding and neutralizing antibody production.4 While the COVID-19 vaccines are not the first to utilize mRNA (previously developed for viruses, including: influenza, rabies, Zika, and cytomegalovirus),4–8 these vaccines are the first to undergo widespread distribution. With expert knowledge of potential cutaneous or systemic dermatologic manifestations of vaccine administration, dermatologists may reassure patients and help the larger healthcare community track emerging adverse reactions.
Local reactions to vaccine administration have been common in recipients of mRNA vaccines. In an mRNA rabies vaccine trial, 95% of recipients reported cutaneous injection site reactions within seven days of vaccination.7 While local injection site reactions such as pain, swelling, and erythema have been connected with mRNA vaccines, no systemic cutaneous adverse reactions have yet been reported (Table 1).5–8 Clinical studies of the Pfizer-BioNTech COVID-19 Vaccine reported injection site pain (84.1% of recipients), swelling (10.5%), and erythema (9.5%).2 Injection site pain (92%), swelling (14.7%), and erythema (10%) were also reported in clinical studies of the Moderna COVID-19 Vaccine.3 Notably, local skin reactions occur more frequently following the required, second dose of