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

Recently, an increasing number of cases with delayed large cutaneous reaction after immunisation with mRNA-based vaccines have been reported. This adverse reaction – which is considered a delayed-type or T-cell mediated hypersensitivity reaction – has been described primarily for the Moderna (mRNA-1273) vaccine and to a lesser extent for Comirnaty (Pfizer/BioNTech, BNT162b2).We describe a delayed large cutaneous reaction in a patient who received the viral vector vaccine Vaxzevria (ChAdOx1-S). The time course and clinical symptoms of delayed major skin reaction after vaccination with Moderna or Pfizer/BioNTech have a similar pattern that we recognized in our patient after Vaxzevria vaccination. In contrast to the Moderna vaccine trials, this phenomenon has not been described in the Vaxzevria clinical trials and is to the best of our knowledge the first report of this adverse reaction to a vector-based vaccine against SARS-CoV-2.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 COVID-19 vaccination.