Fudan University - Department of Epidemiology, University of Michigan at Ann Arbor - Department of Epidemiology, Fudan University - School of Public Health, University of Michigan at Ann Arbor - Department of Epidemiology, Fudan University - Key Laboratory of Public Health Safety, Fudan University - School of Public Health, Fudan University - Key Laboratory of Health Technology Assessment, UNICEF China - Child Health and Development, UNICEF China, Fudan University - Shanghai Institute of Infectious Disease and Biosecurity and Fudan University - Department of Epidemiology