Antineutrophil Cytoplasmic Antibody-associated Vasculitis after COVID-19 Vaccination with Pfizer-BioNTech

The extent of rare side effects of mRNA vaccines for coronavirus disease 2019 (COVID-19) remains un-clear. Several cases of antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) following COVID-19 vaccination have been reported. We herein report a 72-year-old man who presented with a fever after receiving the second dose of the Pfizer-BioNTech COVID-19 vaccine. He was diagnosed with acute kid-ney injury due to myeloperoxidase-ANCA-associated vasculitis and was treated with intermittent hemodialy-sis, high-dose prednisolone, and intravenous rituximab. His general symptoms and renal impairment subse-quently improved. When systemic symptoms are prolonged or renal abnormalities appear after COVID-19 vaccination, the possibility of AAV should be considered.