1. Division of Communicable Diseases; Shenzhen CDC; Shenzhen China
2. Department of Social Medicine; Guangdong Pharmaceutical College; Guangzhou China
3. Department of Epidemiology and Biostatistics; Zhengzhou University School of Public Health; Zhengzhou China
4. Department of Epidemiology and Biostatistics; Central South University School of Public Health; Changsha China
5. Department of Epidemiology and Biostatistics; Xi'an Jiaotong University School of Public Health; Xi'an China
6. Department of Gastrointestinal Disease; First Hospital of Shanxi Medical University; Taiyuan China
7. Department of Epidemiology and Biostatistics; Ningxia Medical University School of Public Health; Yinchuan China
8. Institute of Immunization; Shandong CDC; Jinan China
9. Department of Preventive Medicine; Changzhi Medical College; Changzhi China
10. University at Buffalo School of Medicine; Buffalo NY USA
11. National Immunization Program; China CDC; Beijing China