Continued Circulation of Highly Pathogenic H5 Influenza Viruses in Vietnamese Live Bird Markets in 2018–2021
Lizheng Guan,
Lavanya Babujee,
Victoria L. Browning,
Robert Presler,
David Pattinson,
Hang Le Khanh Nguyen,
Vu Mai Phuong Hoang,
Mai Quynh Le,
Harm van Bakel,
Gabriele Neumann,
Yoshihiro Kawaoka
Affiliations
Lizheng Guan
Influenza Research Institute, Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI 53711, USA
Lavanya Babujee
Influenza Research Institute, Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI 53711, USA
Victoria L. Browning
Influenza Research Institute, Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI 53711, USA
Robert Presler
Influenza Research Institute, Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI 53711, USA
David Pattinson
Influenza Research Institute, Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI 53711, USA
Hang Le Khanh Nguyen
National Institute of Hygiene and Epidemiology, Hanoi 100000, Vietnam
Vu Mai Phuong Hoang
National Institute of Hygiene and Epidemiology, Hanoi 100000, Vietnam
Mai Quynh Le
National Institute of Hygiene and Epidemiology, Hanoi 100000, Vietnam
Harm van Bakel
Department of Genetics and Genomic Services, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
Gabriele Neumann
Influenza Research Institute, Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI 53711, USA
Yoshihiro Kawaoka
Influenza Research Institute, Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI 53711, USA
We isolated 77 highly pathogenic avian influenza viruses during routine surveillance in live poultry markets in northern provinces of Vietnam from 2018 to 2021. These viruses are of the H5N6 subtype and belong to HA clades 2.3.4.4g and 2.3.4.4h. Interestingly, we did not detect viruses of clade 2.3.4.4b, which in recent years have dominated in different parts of the world. The viruses isolated in this current study do not encode major determinants of mammalian adaptation (e.g., PB2-E627K or PB1-D701N) but possess amino acid substitutions that may affect viral receptor-binding, replication, or the responses to human antiviral factors. Several of the highly pathogenic H5N6 virus samples contained other influenza viruses, providing an opportunity for reassortment. Collectively, our study demonstrates that the highly pathogenic H5 viruses circulating in Vietnam in 2018–2021 were different from those in other parts of the world, and that the Vietnamese H5 viruses continue to evolve through mutations and reassortment.
