1. Chinese Centre for Disease Control and Prevention, 155 Changbai Road, Changping District, Beijing, 102206, China.
2. National Centre for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, United States of America (USA).
3. National Centre for Chronic and Noncommunicable Disease Control and Prevention, Chinese Centre for Disease Control and Prevention, Beijing, China.
4. School of Public Health, Peking University, Beijing, China.
5. Shanghai Municipal Centre for Disease Control and Prevention, Shanghai, China.
6. Hubei Provincial Centre for Disease Control and Prevention, Wuhan, China.
7. Dalian Centre for Disease Control and Prevention, Dalian, China.
8. Qingdao Centre for Disease Control and Prevention, Qingdao, China.
9. Ningbo Centre for Disease Control and Prevention, Ningbo, China.
10. Guangdong Provincial Centre for Disease Control and Prevention, Guangzhou, China.
11. Zhaoyuan Centre for Disease Control and Prevention, Yantai, China.
12. Fogarty International Center, National Institutes of Health, Bethesda, USA.