Abstract 10847: Tolerability of Sars-cov-2 Mrna Vaccines and Infection for Patients With History of Kawasaki Disease

Introduction: Kawasaki disease (KD) and multisystem inflammatory syndrome in children from COVID-19 infections share overlapping symptoms, suggesting KD patients may be at risk for adverse outcomes from exposure to SARS-CoV-2 mRNA vaccine or infection. Through retrospective review of clinical outcome data, we determined tolerance of KD patients to SARS-CoV-2 antigen exposure. Methods: We evaluated two cohorts using an existing KD database of 826 patients and reviewed individual electronic medical records for the period spanning January 2020 through Jan 2022 via Epic Care Everywhere which includes Washington State immunization records. Vaccine cohort inclusion criteria were (1) age < 21 years at immunization and (2) received one or more Pfizer-BioNTech or Moderna vaccine doses. The COVID-19 infection cohort included (1) age < 21 years and (2) positive SARS-CoV-2 PCR or nuclear capsid IgG. Results: The vaccine cohort contained 153 patients with vaccine distribution by age subgroups shown in Figure 1. Pfizer-BioNTech vaccine was provided for 93.5% and the remaining received Moderna or a combination. 84.3% were fully vaccinated or received a third-dose booster. No clinically severe adverse events occurred including no vaccine-related hospitalizations or outpatient visits. The COVID-19 infection cohort included thirty-seven patients. No patients required hospitalization. The most common symptoms included low grade fever, fatigue, cough, and myalgia with resolution within a few days. Two patients, 9 and 19 years, had extended cough and fatigue for 3-4 weeks. One patient developed COVID-19 within 6 weeks of receiving IVIG for KD. Conclusions: COVID-19 infections and vaccinations are well tolerated in patients with preceding KD. No severe complications occurred in either cohort with only two patients exhibiting prolonged mild symptoms from COVID-19. This study provides assurance regarding vaccine safety and COVID-19 severity for parents of children with KD.