Characterization of a SARS-CoV-2 EG.5.1 clinical isolate in vitro and in vivo
Ryuta Uraki,
Maki Kiso,
Kiyoko Iwatsuki-Horimoto,
Seiya Yamayoshi,
Mutsumi Ito,
Shiho Chiba,
Yuko Sakai-Tagawa,
Masaki Imai,
Yukie Kashima,
Michiko Koga,
Noriko Fuwa,
Nobumasa Okumura,
Masayuki Hojo,
Noriko Iwamoto,
Hideaki Kato,
Hideaki Nakajima,
Norio Ohmagari,
Hiroshi Yotsuyanagi,
Yutaka Suzuki,
Yoshihiro Kawaoka
Affiliations
Ryuta Uraki
Division of Virology, 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
Maki Kiso
Division of Virology, Institute of Medical Science, University of Tokyo, Tokyo 108-8639, Japan
Kiyoko Iwatsuki-Horimoto
Division of Virology, Institute of Medical Science, University of Tokyo, Tokyo 108-8639, Japan
Seiya Yamayoshi
Division of Virology, 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
Mutsumi Ito
Division of Virology, Institute of Medical Science, University of Tokyo, Tokyo 108-8639, Japan
Shiho Chiba
Division of Virology, Institute of Medical Science, University of Tokyo, Tokyo 108-8639, Japan
Yuko Sakai-Tagawa
Division of Virology, Institute of Medical Science, University of Tokyo, Tokyo 108-8639, Japan
Masaki Imai
Division of Virology, 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
Yukie Kashima
Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba 277-0882, Japan
Michiko Koga
Department of Infectious Diseases and Applied Immunology, IMSUT Hospital of The Institute of Medical Science, University of Tokyo, Tokyo 108-8639, Japan; Division of Infectious Diseases, Advanced Clinical Research Center, Institute of Medical Science, University of Tokyo, Tokyo 108-8639, Japan
Noriko Fuwa
Disease Control and Prevention Center, National Center for Global Health and Medicine Hospital, Tokyo 162-8655, Japan
Nobumasa Okumura
Disease Control and Prevention Center, National Center for Global Health and Medicine Hospital, Tokyo 162-8655, Japan
Masayuki Hojo
Department of Respiratory Medicine, National Center for Global Health and Medicine Hospital, Tokyo 162-8655, Japan
Noriko Iwamoto
Disease Control and Prevention Center, National Center for Global Health and Medicine Hospital, Tokyo 162-8655, Japan
Hideaki Kato
Department of Hematology and Clinical Immunology, Yokohama City University School of Medicine, Yokohama 236-0004, Japan; Infection Prevention and Control Department, Yokohama City University Hospital, Kanagawa 236-0004, Japan
Hideaki Nakajima
Department of Stem Cell and Immune Regulation, Yokohama City University Graduate School of Medicine, Kanagawa 236-0004, Japan
Norio Ohmagari
Disease Control and Prevention Center, National Center for Global Health and Medicine Hospital, Tokyo 162-8655, Japan
Hiroshi Yotsuyanagi
Department of Infectious Diseases and Applied Immunology, IMSUT Hospital of The Institute of Medical Science, University of Tokyo, Tokyo 108-8639, Japan; Division of Infectious Diseases, Advanced Clinical Research Center, Institute of Medical Science, University of Tokyo, Tokyo 108-8639, Japan
Yutaka Suzuki
Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba 277-0882, Japan
Yoshihiro Kawaoka
Division of Virology, 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; Influenza Research Institute, Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI 53711, USA; Pandemic Preparedness, Infection and Advanced Research Center (UTOPIA), The University of Tokyo, Tokyo 108-8639, Japan; Corresponding author
Summary: EG.5.1 is a subvariant of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron XBB variant that is rapidly increasing in prevalence worldwide. However, the pathogenicity, transmissibility, and immune evasion properties of isolates of EG.5.1 are largely unknown. Here, we show that there are no obvious differences in growth ability and pathogenicity between EG.5.1 and XBB.1.5 in hamsters. We also demonstrate that, like XBB.1.5, EG.5.1 is transmitted more efficiently between hamsters compared to its predecessor, BA.2. In contrast, unlike XBB.1.5, we detect EG.5.1 in the lungs of four of six exposed hamsters, suggesting that the virus properties of EG.5.1 are different from those of XBB.1.5. Finally, we find that the neutralizing activity of plasma from convalescent individuals against EG.5.1 was slightly, but significantly, lower than that against XBB.1.5 or XBB.1.9.2. Our data suggest that the different virus properties after transmission and the altered antigenicity of EG.5.1 may be driving its increasing prevalence over XBB.1.5 in humans.
