Chinese Center for Disease Control and Prevention (China CDC), Chinese Center for Disease Control and Prevention (China CDC) - NHC Key Laboratory of Biosafety, Zhejiang Provincial Center for Disease Control and Prevention, affiliation not provided to SSRN, affiliation not provided to SSRN, Chinese Center for Disease Control and Prevention (China CDC), Chinese Center for Disease Control and Prevention (China CDC), Chinese Center for Disease Control and Prevention (China CDC), Chinese Center for Disease Control and Prevention (China CDC), Chinese Center for Disease Control and Prevention (China CDC), Chinese Center for Disease Control and Prevention (China CDC) - National Immunization Program, Chinese Center for Disease Control and Prevention (China CDC) - National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention (China CDC) - National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention (China CDC) - National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention (China CDC) - National Institute for Viral Disease Control and Prevention, Zhejiang Provincial Center for Disease Control and Prevention, affiliation not provided to SSRN, affiliation not provided to SSRN, affiliation not provided to SSRN, Chinese Center for Disease Control and Prevention (China CDC), Chinese Center for Disease Control and Prevention (China CDC) - National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention (China CDC) - National Immunization Program and Chinese Center for Disease Control and Prevention (China CDC) - NHC Key Laboratory of Biosafety