1. Department of Epidemiology and Health Statistics, School of Public Health, Anhui Medical University, Hefei, Anhui, China
2. Department of Expanded Program on Immunization, Lu’an Municipal Center for Disease Control and Prevention, Lu’an, Anhui, China
3. Department of Chronic Non-communicable Diseases Prevention and Control, Jin’an District Center for Disease Control and Prevention, Lu’an, Anhui, China
4. Department of Expanded Program on Immunization, Shucheng District Center for Disease Control and Prevention, Lu’an, Anhui, China
5. Department of Preventive Medicine, School of Public Health, Bengbu Medical College, Bengbu, Anhui, China
6. Department of Preventive Medicine, School of Public Health, Wannan Medical College, Wuhu, Anhui, China