1. Allergy and Immunology Center, and Department of Pediatrics, Korea University College of Medicine, Seoul, Korea.
2. Department of Pediatrics, College of Medicine, The Catholic University of Korea, Seoul, Korea.
3. Division of Infectious Diseases, Department of Internal Medicine, National Medical Center, Seoul, Korea.
4. Department of Pediatrics, Hallym University College of Medicine, Chuncheon, Korea.
5. Department of Pediatrics, Korea University Ansan Hospital, Ansan, Korea.
6. Division of Immunization Planning, Korea Disease Control and Prevention Agency, Cheongju, Korea.
7. Department of Pediatrics, Seoul National University College of Medicine, Seoul, Korea.