ABSTRACT
Multisystem inflammatory syndrome in children (MIS-C) is a serious complication that is observed most commonly in pediatric patients following severe acute respiratory syndrome coronavirus 2 infections. However, the mechanism and predictors of disease are poorly understood. There are no prior reports of MIS-C among patients who have been fully vaccinated, and only a single case of MIS in an adult patient who had received his second shot just 4 days prior to symptom onset. Here, we present an adolescent with sickle cell disease who was fully vaccinated against severe acute respiratory syndrome coronavirus 2 and had no prior history of known or suspected infection, who presented in shock and was ultimately diagnosed with MIS-C. This case highlights the importance of clinical suspicion for MIS-C even when patients are fully vaccinated.