1. Division of Foodborne, Waterborne, and Environmental Diseases, Centers for Disease Control and Prevention , Atlanta, Georgia , USA
2. Center for Vaccine Development and Global Health, University of Maryland School of Medicine , Baltimore, Maryland , USA
3. Department of Medicine, Center for Vaccine Development and Global Health, University of Maryland School of Medicine , Baltimore, Maryland , USA
4. Department of Pediatrics, Center for Vaccine Development and Global Health, University of Maryland School of Medicine , Baltimore, Maryland , USA
5. Medical Research Council Unit, The Gambia at the London School of Hygiene and Tropical Medicine , Banjul , The Gambia
6. Center for Global Health Research, Kenya Medical Research Institute , Kisumu , Kenya
7. Division of Global Health Protection, Centers for Disease Control and Prevention , Nairobi , Kenya
8. Centre pour le Développement des Vaccins du Mali (CVD-Mali) , Bamako , Mali