Minimal change disease soon after Pfizer-BioNTech COVID-19 vaccination

We report on the onset of minimal change disease (MCD) presenting with anasarca after a second dose of the messenger RNA (mRNA)-based Pfizer-BioNTech vaccine against coronavirus disease 2019 (COVID-19). A 75-year-old previously healthy male was admitted with rapidly progressive anasarca and proteinuria of 7.7 g/day following the second dose. A kidney biopsy revealed MCD with nephrotic syndrome. He was treated with intravenous methylprednisolone followed by prednisolone, leading to complete remission after 35 days in the hospital. Since definite causality between the vaccine and MCD remains unclear, awareness of this potential adverse effect of mRNA vaccines is important to determine its true incidence and frequency.