1. Department of Epidemiology , National Vaccine Innovation Platform, Center for Global Health, School of Public Health, , Nanjing , China
2. Nanjing Medical University , National Vaccine Innovation Platform, Center for Global Health, School of Public Health, , Nanjing , China
3. Department of Mathematics, School of Science, Xi’an Shiyou University , Xi’an , China
4. Department of Infectious Disease, Jurong Hospital Affiliated to Jiangsu University , Jurong , China