Department of Clinical Lab;
Tianjin First Central Hospital;
Tianjin;
300192;
China;
The First Central Clinical College;
Tianjin Medical University;
Tianjin;
300192;
China;
Department of Clinical Lab;
Tianjin Children's Hospital;
Tianjin;
300074;
China;
COVID-19; SARS-CoV-2 Omicron variant; Clinical characteristics; Pediatric patients; SARS-CoV-2 vaccine;