Related Experiment Video
Updated: Aug 15, 2025
Detection of Polyfunctional T Cells in Children Vaccinated with Japanese Encephalitis Vaccine via the Flow Cytometry Technique
Published on: September 23, 2022
Examination of Adverse Reactions After COVID-19 Vaccination Among Patients With a History of Multisystem Inflammatory
Matthew D Elias1, Dongngan T Truong2, Matthew E Oster3
1Division of Cardiology, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania.
Insights
COVID-19 vaccination after multisystem inflammatory syndrome in children (MIS-C) showed no serious adverse events. These findings indicate a similar safety profile to the general population for vaccinated children with a history of MIS-C.
Area of Science:
- Pediatric immunology
- Vaccinology
- Infectious disease epidemiology
Background:
- Limited data exists on COVID-19 vaccine adverse reactions in children with a history of multisystem inflammatory syndrome in children (MIS-C).
- This data gap can cause vaccine hesitancy among families and healthcare providers.
Purpose of the Study:
- To describe adverse reactions following COVID-19 vaccination in patients previously diagnosed with MIS-C.
Main Methods:
- A multicenter, cross-sectional study surveyed 185 eligible patients (≥5 years old, ≥90 days post-MIS-C diagnosis) across 22 North American centers.
- Data collected included COVID-19 vaccination status and any adverse reactions experienced.
- Statistical comparisons used Wilcoxon rank sum and chi-squared or Fisher exact tests.
Main Results:
- Of 185 vaccinated patients (median age 12.2 years), 48.6% reported minor adverse reactions like arm soreness or fatigue.
- Most reactions were treated with common medications; 2.2% sought medical evaluation without requiring hospitalization.
- No serious adverse events, including myocarditis or MIS-C recurrence, were reported.
Conclusions:
- COVID-19 vaccination in children with a history of MIS-C appears safe, with no serious adverse events observed.
- The safety profile is comparable to that of the general pediatric population.
- Vaccination is recommended at least 90 days after MIS-C diagnosis.
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.
Related Concept Videos
01:14Myocarditis III: Medical Management
01:51Vaccinations
01:27Allergic Drug Reactions
02:06Allergic Reactions
01:27Myocarditis II: Clinical Features and Diagnostic Tests
01:30Hypersensitivities
Types of Hypersensitivities
Hypersensitivity reactions are categorized into four types: Type 1, Type 2, Type 3, and Type 4. Each type has a distinct mechanism...