摘要
Dear Editor,Coronavirus disease 2019(COVID-19)is a novel infectious disease caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2).Compared with previous variants,Omicron strains are more easily transmissible,have a greater ability to evade the human immune response,and are characterized as naturally virulence attenuated.1 During the early stages of the COVID-19 pandemic,it became apparent that children were less easily infected than adults.
基金
supported by the Emergency Grants for SARS-CoV-2 Prevention and Control of Guangdong Province (2021A1111110002).
