A Study to Evaluate the Immunogenicity and Safety of a Recombinant Protein COVID-19 Vaccine as a Booster Dose in Population Aged 12-17 Years

Approximately 300 participants aged 12-17 years old and previously vaccinated with 2 doses of mRNA COVID-19 vaccine (Comirnaty from Pfizer or mRNA-1273 from Moderna, participants previously vaccinated with mRNA1273 are more preferred) will be enrolled in this study and be randomly assigned to SCTV01E Group and mRNA-1273 Group in a ratio of 1:1.