1. Department of Pediatrics, University of California Davis Medical Center, Sacramento, California.
2. Program in International and Community Nutrition, Department of Nutrition, University of California Davis, Davis, California.
3. Division of Infectious Diseases and Vaccinology, School of Public Health, University of California Berkeley, Berkeley, California.
4. University of Arkansas for Medical Sciences, Little Rock, Arkansas.
5. Food and Drug Administration San Francisco District Office, Alameda, California.
6. PATH, Seattle, Washington.
7. Department of Paediatrics and Child Health, Nelson R. Mandela School of Medicine, University of Kwazulu-Natal, Durban, South Africa.
8. Division of Epidemiology, School of Public Health, University of California Berkeley, Berkeley, California.