1. Center for Global Health, School of Public Health, Nanjing Medical University, Nanjing, PR China
2. Vaccine Clinical Evaluation Department, Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, PR China
3. Institute of Global Public Health and Emergency Pharmacy, China Pharmaceutical University, Nanjing, PR China
4. NHC Key Laboratory of Enteric Pathogenic Microbiology, Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, PR China