1. From the Departments of Nutrition (EV, JF, HC, and WWF), Immunology and Infectious Diseases (INK), and Epidemiology (EV and WWF), Harvard School of Public Health, Boston, MA; the Department of Community Health, Brown University, Providence, RI (AB); and the Departments of Microbiology and Immunology (SA) and Pediatrics and Child Health (KM), Muhimbili University College of Health Sciences, Dar es