Nanjing Medical University, Academy of Military Medical Sciences - Institute of Biotechnology, CanSino Biologics Inc., Jiangsu Provincial Center for Disease Control and Prevention - NHC Key Laboratory of Enteric Pathogenic Microbiology, Chinese Center for Disease Control and Prevention (China CDC) - National Immunization Program, Jiangsu Provincial Center for Disease Control and Prevention - NHC Key Laboratory of Enteric Pathogenic Microbiology, Academy of Military Medical Sciences - Institute of Biotechnology, Chinese Center for Disease Control and Prevention (China CDC), Academy of Military Medical Sciences - Institute of Biotechnology, Jiangsu Provincial Center for Disease Control and Prevention - NHC Key Laboratory of Enteric Pathogenic Microbiology, Government of the People's Republic of China - Center of Disease Control and Prevention, Chongqing Center for Disease Control and Prevention, Nanjing Medical University - School of Public Health, Anhui Provincial Center for Disease Control and Prevention, Chongqing Center for Disease Control and Prevention, Shandong Provincial Center for Disease Control and Prevention, Yunan Provincial Center for Disease Control and Prevention, Hunan Provincial Center for Disease Control and Prevention, Anhui Provincial Center for Disease Control and Prevention, Hunan Provincial Center for Disease Control and Prevention, Yunan Provincial Center for Disease Control and Prevention, CanSino Biologics Inc., Nanjing Medical University - Department of Epidemiology and Biostatistics, Academy of Military Medical Sciences - Institute of Biotechnology and Jiangsu Provincial Center for Disease Control and Prevention - NHC Key Laboratory of Enteric Pathogenic Microbiology

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

Chinese Center for Disease Control and Prevention (China CDC), Anhui Medical University, Zibo Municipal Center for Disease Control and Prevention, Tongchaun Municipal Center for Disease Control and Prevention, Chinese Center for Disease Control and Prevention (China CDC), Lu’an Municipal Center for Disease Control and Prevention, Lu’an Municipal Center for Disease Control and Prevention, Zibo Municipal Center for Disease Control and Prevention, Tongchaun Municipal Center for Disease Control and Prevention, 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) and Chinese Center for Disease Control and Prevention (China CDC) - National Immunization Program

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 Academy of Sciences (CAS) and Please see PDF for full list of authors & affiliations