Highly pathogenic avian influenza H5N1: history, current situation, and outlook

Florian Krammer; Enikö Hermann; Angela L Rasmussen

doi:10.1128/jvi.02209-24

Highly pathogenic avian influenza H5N1: history, current situation, and outlook

J Virol. 2025 Apr 15;99(4):e0220924. doi: 10.1128/jvi.02209-24. Epub 2025 Mar 27.

Authors

Florian Krammer^{1

2

3

4}, Enikö Hermann⁴, Angela L Rasmussen^{5

6

7}

Affiliations

¹ Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, New York, USA.
² Center for Vaccine Research and Pandemic Preparedness (C-VaRPP), Icahn School of Medicine at Mount Sinai, New York, New York, USA.
³ Department of Pathology, Molecular and Cell-Based Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, USA.
⁴ Ignaz Semmelweis Institute, Interuniversity Institute for Infection Research, Medical University of Vienna, Vienna, Vienna, Austria.
⁵ Vaccine and Infectious Disease Organization, University of Saskatchewan, Saskatoon, Saskatchewan, Canada.
⁶ Department of Biochemistry, Microbiology, and Immunology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada.
⁷ Department of Ecology and Evolution, Stony Brook University, Stony Brook, New York, USA.

Abstract

The H5N1 avian panzootic has resulted in cross-species transmission to birds and mammals, causing outbreaks in wildlife, poultry, and US dairy cattle with a range of host-dependent pathogenic outcomes. Although no human-to-human transmission has been observed, the rising number of zoonotic human cases creates opportunities for adaptive mutation or reassortment. This Gem explores the history, evolution, virology, and epidemiology of clade 2.3.4.4b H5N1 relative to its pandemic potential. Pandemic risk reduction measures are urgently required.

Keywords: H5N1; avian viruses; evolution; influenza vaccines; influenza virus; pandemic risk; reassortment; viral pathogenesis; virus-host interactions; zoonotic infections.

Publication types

Historical Article
Review

MeSH terms

Animals
Birds
Cattle
Disease Outbreaks
History, 20th Century
History, 21st Century
Humans
Influenza A Virus, H5N1 Subtype* / classification
Influenza A Virus, H5N1 Subtype* / genetics
Influenza A Virus, H5N1 Subtype* / pathogenicity
Influenza in Birds* / epidemiology
Influenza in Birds* / history
Influenza in Birds* / transmission
Influenza in Birds* / virology
Influenza, Human* / epidemiology
Influenza, Human* / transmission
Influenza, Human* / virology
Pandemics
Poultry
Viral Zoonoses / epidemiology
Viral Zoonoses / transmission
Viral Zoonoses / virology
Zoonoses / epidemiology
Zoonoses / transmission
Zoonoses / virology

Abstract

Publication types

MeSH terms

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