Examination of Adverse Reactions After COVID-19 Vaccination Among Patients With a History of Multisystem Inflammatory Syndrome in Children.

Importance: Data are limited regarding adverse reactions after COVID-19 vaccination in patients with a history of multisystem inflammatory syndrome in children (MIS-C). The lack of vaccine safety data in this unique population may cause hesitancy and concern for many families and health care professionals. Objective: To describe adverse reactions following COVID-19 vaccination in patients with a history of MIS-C. Design, Setting, and Participants: In this multicenter cross-sectional study including 22 North American centers participating in a National Heart, Lung, and Blood Institute, National Institutes of Health-sponsored study, Long-Term Outcomes After the Multisystem Inflammatory Syndrome in Children (MUSIC), patients with a prior diagnosis of MIS-C who were eligible for COVID-19 vaccination (age ≥5 years; ≥90 days after MIS-C diagnosis) were surveyed between December 13, 2021, and February 18, 2022, regarding COVID-19 vaccination status and adverse reactions. Exposures: COVID-19 vaccination after MIS-C diagnosis. Main Outcomes and Measures: The main outcome was adverse reactions following COVID-19 vaccination. Comparisons were made using the Wilcoxon rank sum test for continuous variables and the χ2 or Fisher exact test for categorical variables. Results: Of 385 vaccine-eligible patients who were surveyed, 185 (48.1%) received at least 1 vaccine dose; 136 of the vaccinated patients (73.5%) were male, and the median age was 12.2 years (IQR, 9.5-14.7 years). Among vaccinated patients, 1 (0.5%) identified as American Indian/Alaska Native, non-Hispanic; 9 (4.9%) as Asian, non-Hispanic; 45 (24.3%) as Black, non-Hispanic; 59 (31.9%) as Hispanic or Latino; 53 (28.6%) as White, non-Hispanic; 2 (1.1%) as multiracial, non-Hispanic; and 2 (1.1%) as other, non-Hispanic; 14 (7.6%) had unknown or undeclared race and ethnicity. The median time from MIS-C diagnosis to first vaccine dose was 9.0 months (IQR, 5.1-11.9 months); 31 patients (16.8%) received 1 dose, 142 (76.8%) received 2 doses, and 12 (6.5%) received 3 doses. Almost all patients received the BNT162b2 vaccine (347 of 351 vaccine doses [98.9%]). Minor adverse reactions were observed in 90 patients (48.6%) and were most often arm soreness (62 patients [33.5%]) and/or fatigue (32 [17.3%]). In 32 patients (17.3%), adverse reactions were treated with medications, most commonly acetaminophen (21 patients [11.4%]) or ibuprofen (11 [5.9%]). Four patients (2.2%) sought medical evaluation, but none required testing or hospitalization. There were no patients with any serious adverse events, including myocarditis or recurrence of MIS-C. Conclusions and Relevance: In this cross-sectional study of patients with a history of MIS-C, no serious adverse events were reported after COVID-19 vaccination. These findings suggest that the safety profile of COVID-19 vaccination administered at least 90 days following MIS-C diagnosis appears to be similar to that in the general population.

Vitamin D and morbidity in children with Multisystem inflammatory syndrome related to Covid-19.

Background: Multisystem inflammatory syndrome (MIS-C) is a clinical presentation reported in children related to Coronavirus-19 infection who present with a toxic shock like syndrome. Vitamin D deficiency has been postulated to play a role with severity of coronavirus infection in adult patients and other viral respiratory infections. Objective: This study aims to investigate if severe vitamin D deficiency was associated with increased disease severity and cardiac involvement in MIS-C. Methods: This is a retrospective and single center study. We included hospitalized patients less than 18 years of age with diagnosis of MIS-C between March and July 2020. Severe vitamin D deficiency was defined as 25-OH vitamin D level < 10 ng/ml within 48 h of admission. The composite outcome severe disease included patients requiring inotropes, mechanical ventilation, and extracorporeal membrane oxygenation. Results: Of the 31 patients with MIS-C, 45% were male and 58% were African American. The median age was 8 (1-13) years. Ten patients had severe vitamin D deficiency with a mean level of 7.2 ng/ml. Ninety percent of patients with severe vitamin D deficiency had severe disease (P < 0.001). Patients with severe vitamin D deficiency had an increased risk of cardiac involvement (P < 0.001). Conclusions: We describe a potential association between severe vitamin D deficiency and severe disease in children presenting with MIS-C. Severe vitamin D deficiency predisposes patients for cardiovascular involvement and may play a critical role in the host immune response to COVID-19 infection. Future prospective studies at the basic science and clinical level should be pursued to better delineate this association.

Echocardiographic Indicators Associated with Adverse Clinical Course and Cardiac Sequelae in Multisystem Inflammatory Syndrome in Children with Coronavirus Disease 2019.

BACKGROUND: Multisystem inflammatory syndrome in children (MIS-C) associated with coronavirus disease 2019 causes significant cardiovascular involvement, which can be a determinant of clinical course and outcome. The aim of this study was to investigate whether echocardiographic measures of ventricular function were independently associated with adverse clinical course and cardiac sequelae in patients with MIS-C. METHODS: In a longitudinal observational study of 54 patients with MIS-C (mean age, 6.8 ± 4.4 years; 46% male; 56% African American), measures of ventricular function and morphometry at initial presentation, predischarge, and at a median of 3- and 10-week follow-up were retrospectively analyzed and were compared with those in 108 age- and gender-matched normal control subjects. The magnitude of strain is expressed as an absolute value. Risk stratification for adverse clinical course and outcomes were analyzed among the tertiles of clinical and echocardiographic data using analysis of variance and univariate and multivariate regression. RESULTS: Median left ventricular apical four-chamber peak longitudinal strain (LVA4LS) and left ventricular global longitudinal strain (LVGLS) at initial presentation were significantly decreased in patients with MIS-C compared with the normal cohort (16.2% and 15.1% vs 22.3% and 22.0%, respectively, P < .01). Patients in the lowest LVA4LS tertile (<13%) had significantly higher C-reactive protein and high-sensitivity troponin, need for intensive care, and need for mechanical life support as well as longer hospital length of stay compared with those in the highest tertile (>18.5%; P < .01). Initial LVA4LS and LVGLS were normal in 13 of 54 and 10 of 39 patients, respectively. There was no mortality. In multivariate regression, only LVA4LS was associated with both the need for intensive care and length of stay. At median 10-week follow-up to date, seven of 36 patients (19%) and six of 25 patients (24%) had abnormal LVA4LS and LVGLS, respectively. Initial LVA4LS < 16.2% indicated abnormal LVA4LS at follow-up with 100% sensitivity. CONCLUSION: Impaired LVGLS and LVA4LS at initial presentation independently indicate a higher risk for adverse acute clinical course and persistent subclinical left ventricular dysfunction at 10-week follow-up, suggesting that they could be applied to identify higher risk children with MIS-C.