1. Department of Pediatrics, Yonsei University College of Medicine, Severance Children's Hospital, Korea.
2. Department of Pediatrics, Kangnam Severance Hospital, Korea.
3. Department of Pediatrics, Ewha Womans University College of Medicine, Korea.
4. Division of Influenza, Korea Centers for Disease Control and Prevention, Korea.
5. Division of Respiratory Viruses, Korea Centers for Disease Control and Prevention, Korea.