*For the 106 with vaccinated reported, 93 received monovalent Pfizer-BioNTech (BNT162b2) COVID-19 vaccine, 2 received monovalent Moderna mRNA-1273 COVID-19 vaccine, and 11 received unknown vaccine type.

†P-values obtained using Chi square for categorical variables and Kruskal-Wallis for continuous. Fischer’s Exact test used for categorical variables when cell sizes were <5.

‡Age calculated at time of MIS-C illness onset.

§Sex missing for one person in unvaccinated group

¶Race/ethnicity missing for 87 in the vaccine not reported group and 8 in the primary series vaccination group. Other race includes American Indian/Alaska Native, Pacific Islander, those listed as multiple, and those with race listed as other.

∥The unvaccinated group also included 3 additional persons not shown in the table from the Island Areas census region (1 from Guam and 2 from the US Virgin Islands).

**SVI missing for 13 persons in vaccinated group and 147 in unvaccinated group.

††Either noted as a clinical diagnosis or BMI > 95th percentile when BMI percentile was available.

‡‡Severe cardiovascular involvement defined as ventricular dysfunction, pericardial effusion/pericarditis, myocarditis, congestive heart failure, arrythmia, elevated troponin, elevated BNP, or NT-pro BNP ≥ 1,000 pg./mL, shock/receipt of vasopressors, or extracorporeal membranous oxygenation (ECMO) [2]

§§Severe gastrointestinal involvement defined as mesenteric adenitis, free fluid, hepatomegaly/splenomegaly, colitis/enteritis, cholecystitis/gallbladder abnormalities, or appendicitis/appendiceal changes [2]

¶¶Severe hematologic defined as thrombocytopenia, lymphopenia, neutropenia, or thrombosis [2]

∥∥Defined as ICU admission indicated on case report form or receipt of invasive ventilation, vasopressors, or extracorporeal membranous oxygenation (ECMO)