1. Division of Infectious Diseases, Department of Internal Medicine, National Health Insurance Corporation Ilsan Hospital, Goyang, Korea.
2. Vaccine Bio Research Institute, College of Medicine, The Catholic University of Korea, Seoul, Korea.
3. Division of Infectious Diseases, Department of Internal Medicine, Korea University College of Medicine, Seoul, Korea.
4. Division of Infectious Diseases, Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, Korea.
5. Department of Laboratory Medicine, College of Medicine, The Catholic University of Korea, Seoul, Korea.