Delayed Cutaneous Hypersensitivity Reaction to Vaxzevria (ChAdOx1-S) Vaccine against SARS-CoV-2

Recently, an increasing number of cases with delayed cutaneous reaction after immunization with mRNA-based vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been reported. This adverse reaction, which is considered a delayed-type or T cell-mediated hypersensitivity reaction, has been described for the Moderna (mRNA-1273) and Comirnaty (Pfizer/BioNTech, BNT162b2) vaccines. We describe a delayed large local cutaneous reaction in a patient who received the viral vector vaccine Vaxzevria (ChAdOx1-S, AstraZeneca). The time course and clinical symptoms of delayed skin reaction after mRNA vaccines have a similar pattern that we recognized in our patient after Vaxzevria vaccination. This phenomenon has not been described in the Vaxzevria clinical trials and is to our knowledge the first report of this adverse reaction to a vector-based SARS-CoV-2 vaccine. With this, we hope to raise awareness about delayed injection site reactions that also occur after viral vector vaccines and to encourage additional reporting and patient education regarding the cutaneous reactions after coronavirus disease 2019 (COVID-19) vaccination.