1. School of Public Health, Shanxi Medical University, Taiyuan, Shanxi PR, China
2. Center of Clinical Epidemiology and Evidence Based Medicine, Shanxi Medical University, Taiyuan, Shanxi PR, China
3. Department of Infectious Diseases, The Second Hospital of Yuncheng, Yuncheng, Shanxi PR, China
4. Department of STD and AIDS Control and Prevention, Shanxi Provincial Center for Disease Control and Prevention, Shanxi, PR, China
5. Department of National Immunization Program, Chinese Center for Disease Control and Prevention, Beijing, PR China
6. Chinese Preventive Medicine Association, Beijing, PR China