Multisystem inflammatory syndrome in a male adolescent after his second Pfizer-BioNTech COVID-19 vaccine.

Multisystem inflammatory syndrome (MIS) in children (MIS-C) is a complication of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, while myocarditis is a rare adverse effect to messenger ribonucleic acid (mRNA) SARS-CoV-2 vaccines, especially in males aged 12-17 years.