Critical COVID-19 in children and adolescents during the 2022 Omicron Surge in Taiwan: Risk factors and vaccine effectiveness.

Abstract

Background/aim: Critical coronavirus disease 2019 (COVID-19) is a rare but devastating complication of SARS-CoV-2 Omicron variant infection in children and adolescents. This study aimed to assess the risk factors for, and evaluate the vaccine effectiveness against, critical COVID-19 during the 2022 Omicron Surge in Taiwan.

Methods: We retrospectively enrolled 41 pediatric patients with critical COVID-19 (which required mechanical ventilation, inotropic agents, extracorporeal membrane oxygenator, or resulting in in-hospital death) and 793 with non-critical COVID-19 who were hospitalized at National Taiwan University Children Hospital during the 2022 Omicron Surge. To estimate vaccine effectiveness, population controls generated using the Monte Carlo method from national vaccination statistics were matched to critical COVID-19 cases at a ratio of 10:1 by age group and disease onset date.

Results: Only one of 41 critical COVID-19 cases had no underlying diseases. Underlying cardiovascular diseases (adjusted odds ratio [aOR] 5.4, 95% confidence interval [CI] 2.5-11.5), hematological diseases (aOR 4.9, 95% CI 2.3-10.6), neuropsychological disorders (aOR 3.8, 95% CI 1.8-7.9), or respiratory diseases (aOR 2.8, 95% CI 1.3-6.4) were risk factors for critical COVID-19. The effectiveness of two-dose and one-dose vaccination against critical diseases were 93.5% (95% CI: 70.4%-98.6%) and 75.2% (95% CI 9.2%-93.2%), respectively.

Conclusions: Underlying diseases are the major risk factors for critical COVID-19 among children and adolescents during the Omicron Surge. The two-dose COVID-19 vaccination is highly effective against critical diseases.