Vet Sci . Highly Pathogenic Avian Influenza A(H5N1) Virus: How Far Are We from a New Pandemic?

[tetano]

Vet Sci


. 2025 Jun 9;12(6):566.
doi: 10.3390/vetsci12060566. Highly Pathogenic Avian Influenza A(H5N1) Virus: How Far Are We from a New Pandemic?

Giovanni Di Guardo[SUP] 1 [/SUP]



Affiliations

• PMID: 40559803
• PMCID: PMC12197710
• DOI: 10.3390/vetsci12060566

Abstract

The focus of this commentary is represented by the pandemic risk associated with the highly pathogenic avian influenza (HPAI) A(H5N1) virus, clade 2.3.4.4b. More in detail, the herein dealt pandemic alarm appears to be primarily justified by the huge and progressively growing number of virus-susceptible domestic and wild birds and mammals, including threatened marine mammal species like South American sea lions and elephant seals as well as harbour porpoises, bottlenose dolphins and polar bears. Of major concern is the susceptibility of dairy cattle to HPAI A(H5N1) virus, particularly the documented and unprecedented colonization of host's mammary gland tissue, resulting in viral shedding through the milk alongside a large series of cases of infection in dairy farm workers in several USA locations. Despite well-documented zoonotic capability, no evidences of a sustained and efficient HPAI A(H5N1) viral transmission between people have been hitherto reported. If this were to happen sooner or later, a new pandemic might consequently arise. Therefore, keeping all this in mind and based upon the lessons taught by the COVID-19 pandemic, a "One Health, One Earth, One Ocean"-centered approach would be absolutely needed in order to deal in the most appropriate way with the HPAI A(H5N1) virus-associated zoonotic and pandemic risk.

Keywords: birds; cattle H5N1; cow H5N1; emerging infectious diseases; highly pathogenic avian influenza A(H5N1) virus; mammals; pandemic risk; pandemics; susceptible hosts’ range; zoonoses.

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[Commonground]

Excerpt from above report:



Finally, since the global spread of HPAI A(H5N1) virus poses a serious pandemic threat, the swift development of effective human and animal vaccines should be viewed as a top priority, although we would be profoundly mistaken whenever thinking this should be the only action to be undertaken for efficiently tackling the potential start of a new pandemic. To this aim, the success of messenger RNA (mRNA) technology-based vaccines in efficiently counteracting the COVID-19 pandemic demonstrates its potential for addressing other infectious threats in people as well as in animals, such as the herein dealt HPAI A(H5N1) viral clade 2.3.4.4b. This has been clearly shown, for example, in ferrets previously immunized with ad hoc mRNA vaccines against viral HA and NA antigens, which were subsequently challenged with a lethal dose of HPAI A(H5N1) virus [23].

As a concluding remark, it is my strong belief that we should firmly keep in mind, first of all, the memorable and remarkable lessons taught by the COVID-19 pandemic and, more in general, by past infectious disease outbreaks caused by zoonotic pathogens, as it happened over one century ago with the catastrophic “Spanish flu” pandemic. Indeed, while it seems undeniable that the history of mankind, along with that of all living organisms, has been continuously shaped by infectious agents, within complex host–pathogen coevolutionary dynamics, it should also be emphasized that the origin of “emerging infectious diseases”, either proven or suspect, lies for two thirds of them in one or more animal reservoirs [24]. In consideration of the above, the “One Health, One Earth, One Ocean” paradigm, reminding us that human, animal and environmental health are mutually and inextricably linked to each other, should be regarded as the leading principle and the necessary prerequisite upon which we should develop all the actions and strategies for efficiently tackling and counteracting HPAI A(H5N1) virus spread among birds and mammals as well as from birds and mammals to humans (and vice versa) and, most importantly, between human beings, with the aim of avoiding a future pandemic. Among such actions and strategies, the following ones should be viewed as top priorities: (a) building a tight collaboration between human and animal health sectors; (b) improving eco-epidemiological surveillance for early detection of human infectious disease threats; (c) strengthening laboratory diagnostic capacities for novel microbial pathogens; (d) developing epidemic/pandemic preparedness for and response to emerging infectious agents; (e) tracking and communicating the appearance and subsequent spread among people and animals of new genetic mutants and/or reassortants of previously known pathogens; (f) developing and employing ad hoc risk analysis protocols related to infectious disease threats; (g) setting up ad hoc vaccines and immunization protocols [25].

Within such a challenging, complex and largely unpredictable scenario, it is hard to believe that the “COVID-19 Scientific Committee”, popularly known by the acronym “CTS” (standing for “Comitato Tecnico-Scientifico”) and which was officially set up in February 2020 by the Italian government for counteracting the COVID-19 pandemic, was inexplicably dismantled two years later, with no veterinarians having ever been co-opted in it. How useful, by contrast, would have been a similar “organism” (duly revisited in its composition, thus including ad hoc veterinary medical expertise) for efficiently tackling, preventing, predicting, quantifying, handling and communicating the risk of future epidemic and pandemic human and animal disease outbreaks [26]!

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