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#Vaccination against #H5 HP #influenza virus leads to persistent immune response in wild king #penguins

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By G.M.

 


Abstract

Since 2021, the panzootic of high pathogenicity avian influenza (HPAI) represents an increasing threat to wild vertebrate populations. In this context, recent vaccines developed for poultry could provide tools for the conservation of wild endangered birds populations. The king penguin (Aptenodytes patagonicus), a long-lived seabird breeding in dense colonies with an extended chick-rearing period, was identified as a possible surrogate species for a vaccination trial in a sub-Antarctic natural setting. We investigate here the immune response of king penguin chicks to a self-amplifying mRNA vaccine against a H5 HPAI clade 2.3.4.4b protein. Thirty chicks were vaccinated (primo- and boost-injections), 20 were kept as controls. Along 250 days of monitoring, vaccinated chicks showed a high and persistent immune response, granting a strong seroneutralisation capacity against the virus, up to fledging. No adverse effects were observed. The screening for antibodies against unspecific avian influenza viruses suggested that no natural infection occurred over the entire trial. The emergence of HPAI in the Southern Indian Ocean in October 2024 highlights the timeliness of such experimental tests. Our results show the vaccine could provide a powerful tool for mitigation and emphasises the need for studies considering ethical and practical issues of vaccination for wildlife conservation.


Competing Interest Statement

The authors declare as only conflict of interest that the work was partially funded by Ceva Wildlife Research Fund, an endowment fund created by Ceva Sante Animale, whose objective is to support applied animal health research projects contributing to wildlife conservation. Ceva Wildlife Research Fund had no role in the conceptualization, design, data collection, analysis, decision to publish, or preparation of the manuscript.


Funder Information Declared

French Polar Institute (IPEV), Project ECOPATH-1151, Project ECOENERGY-119

Agence Nationale de la Recherche, https://ror.org/00rbzpz17, ECOPATHS ANR-21-CE35-0016, WILDFLU ANR-2025-CE35-00XX

Ceva Wildlife Research Fund, CWRF2

Source: BioRxIV, https://www.biorxiv.org/content/10.1101/2025.09.06.674613v1

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