1. Department of Microbiology, Yokohama City University School of Medicine, Kanagawa 236-0004, Japan
2. Advanced Medical Research Center, Yokohama City University, Kanagawa 236-0004, Japan
3. Bioscience Division, Reagent Development Department, Tosoh Corporation, Kanagawa 252-1123, Japan
4. Life Science Laboratory, Technology and Development Division, Kanto Chemical Co., Inc., Kanagawa 259-1146, Japan
5. Department of Emergency Medicine, Yokohama City University Hospital, Kanagawa 236-0004, Japan
6. School of Medical Technology, Faculty of Health Sciences, Gunma Paz University, Gunma 370-0006, Japan
7. Influenza Research Center, National Institute of Infectious Diseases, Tokyo 208-0011, Japan