1. Influenza Division, Center for Immunization and Respiratory Diseases Centers for Disease Control and Prevention Atlanta Georgia USA
2. Battelle Memorial Institute Atlanta Georgia USA
3. Division of Child and Adolescent Health, Department of Pediatrics, College of Physicians and Surgeons Columbia University New York New York USA
4. Department of Population and Family Health, Mailman School of Public Health Columbia University New York New York USA
5. Division of Pediatric Infectious Diseases, Department of Pediatrics, College of Physicians and Surgeons Columbia University New York New York USA