Severe coronavirus disease 2019 in pediatric solid organ transplant recipients: Big data convergence study in Korea (K-COV-N cohort)

OBJECTIVES: The risk of severe COVID-19 in children with a solid organ transplant (SOT) is not well established. We compare the relative risk of severe COVID-19 infection between pediatric SOT and non-SOT children. METHODS: The newly constructed K-COV-N cohort (Korea Disease Control and Prevention Agency-COVID-19-National Health Insurance Service) was used. Children with COVID-19 (<18 years old) who underwent SOT between January 2008–January 2022 were included. Non-SOT children with COVID-19 were selected in a ratio of 1:4 using propensity score matching. Three definitions of severe COVID-19 were established based on their requirement of respiratory support: Severe I (requiring respiratory support above a high-flow nasal cannula or prolonged hospitalization ≥6 days), Severe II (requiring any oxygen supplement), and Severe III (requiring any oxygen supplement or prolonged hospitalization ≥6 days). RESULTS: Among 2,957,323 children with COVID-19, 206 pediatric SOTRs were identified and included in the analysis along with 803 matched non-SOT children. Most infections (96.6%) occurred during the Omicron period; no cases of mortality were reported. Pediatric SOTR had a 3.6-fold (95% CI=1.1–11.7, P=0.03) higher risk of Severe I, and a 4.9-fold (95% CI=1.6–15.0, P=0.006) higher risk of Severe III than non-SOT children. No cases of Severe II occurred in the non-SOT children. Although not statistically significant, no severe COVID-19 cases were reported in the vaccinated SOT group (0.0% vs 5.7%, P=0.09 in Severe III). CONCLUSIONS: Pediatric SOTRs have a significantly higher risk of severe COVID-19 than non-SOT children. Our findings support the need for tailored strategies for these high-risk children.