Multisystem Inflamatory Syndrome After SARS-CoV-2 Infection and COVID-19 Vaccination

Mark B. Salzman; Cheng-Wei Huang; Christopher M. O'Brien; Rhina D. Castillo


Emerging Infectious Diseases. 2021;27(7):1944-1948. 

In This Article

Abstract and Introduction


We report 3 patients in California, USA, who experienced multisystem inflammatory syndrome (MIS) after immunization and severe acute respiratory syndrome coronavirus 2 infection. During the same period, 3 adults who were not vaccinated had MIS develop at a time when ≈7% of the adult patient population had received ≥1 vaccine.


Multisystem inflammatory syndrome (MIS) in children (MIS-C) and adults (MIS-A) are febrile syndromes with elevated inflammatory markers that usually manifest 2–6 weeks after a severe acute respiratory syndrome 2 (SARS-CoV-2) infection.[1–3] The Brighton Collaboration Case Definition for MIS-C/A was recently published to be used in the evaluation of patients after SARS-CoV-2 immunization;[3] some scientists are concerned that vaccination against SARS-CoV-2 can trigger MIS-C/A. We report 6 cases of MIS from a large integrated health system in Southern California, USA; 3 of those patients received SARS-CoV-2 vaccination shortly before seeking care for MIS. All 6 patients met the Brighton Collaboration Level 1 of diagnostic certainty for a definitive case and had MIS illness onset between January 15–February 15, 2021. The Chief Compliance Officer for the Southern California Permanente Medical Group reviewed this case series and confirmed that it was compliant with the Health Insurance Portability and Accountability Act for publication.