摘要
Coronavirus disease 2019(COVID-19)is a new type of respiratory disease caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),which has caused severe social and economic costs and has become a great threat to public health because of the high mortality rate.Recent studies indicated that respiratory pathogens co-infection and secondary infection were critical risk factors for the severity and mortality rates of COVID-19(Zhou et al.,2020).
基金
supported by grants from National Natural Science Foundation of China(32025009,91951209,31722031)。