1. Kanonji Institute, The Research Foundation for Microbial Diseases of Osaka University, Kanonji, Kagawa, Japan.
2. Laboratory of Virology and Vaccinology, Division of Biomedical Research, National Institute of Biomedical Innovation, Ibaraki, Osaka, Japan.
3. Department of Biotechnology, Graduate School of Engineering, Osaka University, Osaka, Japan.
4. Department of Pathology, National Institute of Infectious Diseases, Tokyo, Japan.
5. Division of Clinical Virology, Department of Microbiology and Infectious Diseases, Kobe University Graduate School of Medicine, Kobe, Japan.