1. Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, Maryland 21201
2. Israel Institute for Biological Research, Ness Ziona, Israel
3. Centre pour le Développement des Vaccins, Bamako, Mali
4. National Salmonella Reference Laboratory, Centers for Disease Control and Prevention, Atlanta, Georgia 30333
5. Centro para Vacunas en Desarrollo, Hospital de Niños Roberto del Rio, Servicio de Salud Metropolitano Norte, Santiago, Chile