1 National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Disease, Beijing 102206, China;National Immunization Program, Chinese Center for Disease Control and Prevention, Beijing 100050, China.
2 Lu'an Center for Disease Control and Prevention, Lu'an 23700, Anhui China.
3 Zibo Center for Disease Control and Prevention, Zibo 255026, Shandong, China.
4 Tongchuan Center for Disease Control and Prevention, Tongchuan 727031, Shaanxi, China.