1. Department of Virology, Research Institute for Microbial Diseases, Osaka University, Osaka 565-0871, Japan
2. Department of Human Mucosal Vaccinology, Chiba University Hospital, Chiba 260-8670, Japan
3. Department of Microbiology and Immunology, School of Pharmaceutical Sciences, Wakayama Medical University, Wakayama 640-8156, Japan
4. Department of Microbiology, Osaka Institute of Public Health, Osaka 537-0025, Japan
5. Division of Microbiology, Department of Pathology and Microbiology, Nihon University School of Medicine, Tokyo 173-8610, Japan
6. Future Medicine Education and Research Organization, Chiba University, Chiba 263-8522, Japan
7. CU-UCSD Center for Mucosal Immunology, Allergy, and Vaccines (cMAV), Departments of Medicine and Pathology, University of California, San Diego, CA 92093-0956, USA