1 Pandemic Preparedness, Infection and Advanced Research Center, the University of Tokyo (UTOPIA), Tokyo, 108-8639, Japan; Influenza Research Institute, Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin, Madison, WI, 53711, USA; Division of Virology, Department of Microbiology and Immunology, Institute of Medical Science, University of Tokyo, Tokyo, 108-8639, Japan.
2 Pandemic Preparedness, Infection and Advanced Research Center, the University of Tokyo (UTOPIA), Tokyo, 108-8639, Japan; Division of Virology, Department of Microbiology and Immunology, Institute of Medical Science, University of Tokyo, Tokyo, 108-8639, Japan.
3 Vaccine Research Laboratories, Research Function, R&D Division, Daiichi Sankyo Co., Ltd., Tokyo, 134-8630, Japan.
4 Pandemic Preparedness, Infection and Advanced Research Center, the University of Tokyo (UTOPIA), Tokyo, 108-8639, Japan; The Research Center for Global Viral Diseases, National Center for Global Health and Medicine Research Institute, Tokyo, 162-8655, Japan.
5 Pandemic Preparedness, Infection and Advanced Research Center, the University of Tokyo (UTOPIA), Tokyo, 108-8639, Japan; Influenza Research Institute, Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin, Madison, WI, 53711, USA; Division of Virology, Department of Microbiology and Immunology, Institute of Medical Science, University of Tokyo, Tokyo, 108-8639, Japan; The Research Center for Global Viral Diseases, National Center for Global Health and Medicine Research Institute, Tokyo, 162-8655, Japan. Electronic address: [email protected].