Highly pathogenic avian influenza A(H5N1) virus: How far are we from another pandemic?

From Top Italian Scientists Journal
Published
June 1, 2025
Title
Highly pathogenic avian influenza A(H5N1) virus: How far are we from another pandemic?
Author
Giovanni Di Guardo
DOI
10.62684/TYGE2289
Keywords
Highly pathogenic avian influenza.
Downloads
Download PDF
Download PDF

Giovanni Di Guardo

Former Professor of General Pathology and Veterinary Pathophysiology at the Veterinary Medical Faculty of the University of Teramo, Località Piano d’Accio, 64100 Teramo, Italy.

Correspondence to: gdiguardo@unite.it

Abstract

The present Editorial deals with the pandemic risk brought about by the highly pathogenic avian influenza A(H5N1) virus. Such pandemic alarm is justified, among others, by the progressively and rapidly expanding range of virus-susceptible hosts, including humans alongside a huge number of domestic and wild avian and mammalian species, several of which distantly related to each other. Despite its documented zoonotic potential, no clear-cut evidence of viral interhuman transmission has been thus far reported. Should this happen sooner or later, it could pave the way for a new pandemic.

Declarations

Conflict of Interest

The Author declares that there is no conflict of interest.

References

  1. USA Centers for Disease Control and Prevention (CDC). 1880-1959 Highlights in the History of Avian Influenza (Bird Flu) Timeline. DOI: https://www.cdc.gov/bird-flu/avian-timeline/1880-1959.html.
  2. USA Centers for Disease Control and Prevention (CDC). Emergence and Evolution of H5N1 Bird Flu. (2024). DOI:https://www.cdc.gov/flu/avianflu/communication-resources/bird-flu-origin-infographic.html.
  3. USA Centers for Disease Control and Prevention (CDC). About Bird Flu. (2024). DOI: https://www.cdc.gov/flu/avianflu/communication-resources/bird-flu-origin-infographic.html.
  4. Huang P., Sun L., Li J., Wu Q., Rezaei N., Jiang S., Pan C. (2023). Potential cross-species transmission of highly pathogenic avian influenza H5 subtype (HPAI H5) viruses to humans calls for the development of H5-specific and universal influenza vaccines. Cell Discov. 9(1):58. DOI: 10.1038/s41421-023-00571-x.
  5. Uhart M.M., Vanstreels R.E.T., Nelson M.I., Olivera V., Campagna J., Zavattieri V., Lemey P., Campagna C., Falabella V., Rimondi A. (2024). Epidemiological data of an influenza A/H5N1 outbreak in elephant seals in Argentina indicates mammal-to-mammal transmission. Nature Commun. 15(1):9516. DOI: 10.1038/s41467-024-53766-5.
  6. Di Guardo G. (2024). Central Nervous System Disorders of Marine Mammals: Models for Human Disease? Pathogens 13(8):684. DOI: 10.3390/pathogens13080684.
  7. Bauer L., Benavides F.F.W., Veldhuis Kroeze E.J.B., de Wit E., van Riel D. (2023). The neuropathogenesis of highly pathogenic avian influenza H5Nx viruses in mammalian species including humans. Trends Neurosci. 46(11):953-970. DOI: 10.1016/j.tins.2023.08.002.
  8. McKie R. (2024). Next pandemic likely to be caused by flu virus, scientists warn. The Observer. DOI: https://www.theguardian.com/world/2024/apr/20/next-pandemic-likely-to-be-caused-by-flu-virus-scientists-warn.
  9. Mahase E. (2025). H5N1: UK reports world's first case in a sheep. BMJ 388: r591. DOI : https://doi.org/10.1136/bmj.r591.
  10. Burrough E.R., Magstadt D.R., Petersen B., Timmermans S.J., Gauger P.C., Zhang J., Siepker C., Mainenti M., Li G., Thompson A.C., Gorden P.J., Plummer P.J., Main R. (2024). Highly Pathogenic Avian Influenza A(H5N1) Clade 2.3.4.4b Virus Infection in Domestic Dairy Cattle and Cats, United States, 2024. Emerg. Infect. Dis. 30(7):1335-1343. DOI: 10.3201/eid3007.240508.
  11. Garg S., et al. (2025). Highly Pathogenic Avian Influenza A(H5N1) Virus Infections in Humans. N. Engl. J. Med. 392(9):843-854. DOI: 10.1056/NEJMoa2414610.
  12. Gu C., Maemura T., Guan L., et al. (2024). A human isolate of bovine H5N1 is transmissible and lethal in animal models. Nature 636:711-718. DOI: https://doi.org/10.1038/s41586-024-08254-7.