1. Institute for Viral Disease Control and Prevention, Beijing, People’s Republic of China
2. Chinese Center for Disease Control and Prevention, Beijing, People’s Republic of China
3. Shanxi Center for Disease Control and Prevention, Taiyuan, People’s Republic of China
4. Yuncheng Center for Disease Control and Prevention, Yuncheng, People’s Republic of China
5. Yuncheng Infectious Diseases Hospital, Yuncheng, People’s Republic of China. #Beijing Ditan Hospital, Beijing, People’s Republic of China
6. Beijing Institute of Biological Products, Beijing, People’s Republic of China