Division of Systems Virology, Department of Microbiology and Immunology, The Institute of Medical Science, The University of Tokyo, Tokyo, Japan; Faculty of Medicine, Kobe University, Kobe, Japan.
Division of Systems Virology, Department of Microbiology and Immunology, The Institute of Medical Science, The University of Tokyo, Tokyo, Japan.
Division of Molecular Virology and Genetics, Joint Research Center for Human Retrovirus infection, Kumamoto University, Kumamoto, Japan; Department of Clinical Pathology, Faculty of Medicine, Suez Canal University, Ismailia, Egypt.
Department of Microbiology and Immunology, Graduate School of Medicine, Hokkaido University, Sapporo, Japan.
Division of International Research Promotion, International Institute for Zoonosis Control, Hokkaido University, Sapporo, Japan; One Health Research Center, Hokkaido University, Sapporo, Japan.
Division of Systems Virology, Department of Microbiology and Immunology, The Institute of Medical Science, The University of Tokyo, Tokyo, Japan; Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
Department of Cancer Pathology, Faculty of Medicine, Hokkaido University, Sapporo, Japan; Institute for Chemical Reaction Design and Discovery (WPI-ICReDD), Hokkaido University, Sapporo, Japan.
Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, Israel.
Department of Hematology and Oncology, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
Division of Molecular Pathobiology, International Institute for Zoonosis Control, Hokkaido University, Sapporo, Japan.
Division of Systems Virology, Department of Microbiology and Immunology, The Institute of Medical Science, The University of Tokyo, Tokyo, Japan; Laboratory of Systems Virology, Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto, Japan; Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, Japan.
Division of Vaccine Science, Department of Microbiology and Immunology, The Institute of Medical Science, The University of Tokyo, Tokyo, Japan; International Vaccine Design Center, The Institute of Medical Science, The University of Tokyo, Tokyo, Japan.
Division of Vaccine Science, Department of Microbiology and Immunology, The Institute of Medical Science, The University of Tokyo, Tokyo, Japan.
Division of Infection and immunity, Joint Research Center for Human Retrovirus infection, Kumamoto University, Kumamoto, Japan.
Department of Veterinary Science, Faculty of Agriculture, University of Miyazaki, Miyazaki, Japan.
Division of Molecular Virology and Genetics, Joint Research Center for Human Retrovirus infection, Kumamoto University, Kumamoto, Japan.
Department of Cancer Pathology, Faculty of Medicine, Hokkaido University, Sapporo, Japan.
Division of Molecular Pathobiology, International Institute for Zoonosis Control, Hokkaido University, Sapporo, Japan; Department of Veterinary Science, Faculty of Agriculture, University of Miyazaki, Miyazaki, Japan.
Division of Molecular Pathobiology, International Institute for Zoonosis Control, Hokkaido University, Sapporo, Japan; International Collaboration Unit, International Institute for Zoonosis Control, Hokkaido University, Sapporo, Japan.
Institute for Genetic Medicine, Hokkaido University, Sapporo, Japan.
Tokyo Metropolitan Institute of Public Health, Tokyo, Japan.
Interpark Kuramochi Clinic, Utsunomiya, Japan.
Department of Molecular Oncology, Graduate School of Medicine, Chiba University, Chiba, Japan.
Department of Emergency and Critical Care Medicine, Graduate School of Medicine, Chiba University, Chiba, Japan.
Department of Respirology, Graduate School of Medicine, Chiba University, Chiba, Japan.
Division of International Research Promotion, International Institute for Zoonosis Control, Hokkaido University, Sapporo, Japan; One Health Research Center, Hokkaido University, Sapporo, Japan; Division of Molecular Pathobiology, International Institute for Zoonosis Control, Hokkaido University, Sapporo, Japan; International Collaboration Unit, International Institute for Zoonosis Control, Hokkaido University, Sapporo, Japan.
Department of Veterinary Science, Faculty of Agriculture, University of Miyazaki, Miyazaki, Japan; Center for Animal Disease Control, University of Miyazaki, Chiba, Japan; Graduate School of Medicine and Veterinary Medicine, University of Miyazaki, Miyazaki, Japan. Electronic address: sakatsuki@cc.miyazaki-u.ac.jp.
Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan. Electronic address: tirie@hiroshima-u.ac.jp.
Department of Cancer Pathology, Faculty of Medicine, Hokkaido University, Sapporo, Japan; Institute for Chemical Reaction Design and Discovery (WPI-ICReDD), Hokkaido University, Sapporo, Japan. Electronic address: tanaka@med.hokudai.ac.jp.
One Health Research Center, Hokkaido University, Sapporo, Japan; International Collaboration Unit, International Institute for Zoonosis Control, Hokkaido University, Sapporo, Japan; Division of Risk Analysis and Management, International Institute for Zoonosis Control, Hokkaido University, Sapporo, Japan. Electronic address: matsuk@czc.hokudai.ac.jp.
Department of Microbiology and Immunology, Graduate School of Medicine, Hokkaido University, Sapporo, Japan. Electronic address: fukut@pop.med.hokudai.ac.jp.
Division of Molecular Virology and Genetics, Joint Research Center for Human Retrovirus infection, Kumamoto University, Kumamoto, Japan. Electronic address: ikedat@kumamoto-u.ac.jp.
Division of Systems Virology, Department of Microbiology and Immunology, The Institute of Medical Science, The University of Tokyo, Tokyo, Japan; Graduate School of Medicine, The University of Tokyo, Tokyo, Japan; International Vaccine Design Center, The Institute of Medical Science, The University of Tokyo, Tokyo, Japan; International Research Center for Infectious Diseases, The Institute of Medical Science, The University of Tokyo, Tokyo, Japan; CREST, Japan Science and Technology Agency, Kawaguchi, Japan. Electronic address: keisato@g.ecc.u-tokyo.ac.jp.
Soon after the emergence and global spread of the SARS-CoV-2 Omicron lineage BA.1, another Omicron lineage, BA.2, began outcompeting BA.1. The results of statistical analysis showed that the effective reproduction number of BA.2 is 1.4-fold higher than that of BA.1. Neutralization experiments revealed that immunity induced by COVID vaccines widely administered to human populations is not effective against BA.2, similar to BA.1, and that the antigenicity of BA.2 is notably different from that of BA.1. Cell culture experiments showed that the BA.2 spike confers higher replication efficacy in human nasal epithelial cells and is more efficient in mediating syncytia formation than the BA.1 spike. Furthermore, infection experiments using hamsters indicated that the BA.2 spike-bearing virus is more pathogenic than the BA.1 spike-bearing virus. Altogether, the results of our multiscale investigations suggest that the risk of BA.2 to global health is potentially higher than that of BA.1.
