1. Department of Pediatrics, Ewha Womans University School of Medicine, Seoul, Korea.
2. Center for Vaccine Evaluation and Study, Medical Research Institute, Ewha Womans University School of Medicine, Seoul, Korea.
3. Department of Pediatrics, School of Medicine, Jeju National University, Jeju, Korea.
4. Department of Pediatrics, The Catholic University of Korea School of Medicine, Seoul, Korea.
5. College of Pharmacy, Ewha Womans University, Seoul, Korea.
6. Department of Pathology, University of Alabama at Birmingham, Birmingham, Alabama, USA.
7. Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama, USA.