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Baloxavir improves disease outcomes in mice after intranasal or ocular infection with Influenza A virus H5N1-contaminated cow’s milk

Nature Microbiology volume 10, pages 836–840 (2025)Cite this article

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A Publisher Correction to this article was published on 27 March 2025

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Abstract

Testing approved antivirals against A(H5N1) influenza viruses circulating in peridomestic species, including dairy cows, is critical to public health and pre-pandemic planning. It cannot be tested in humans due to A(H5N1) disease severity. Here, in mice, we demonstrate that US FDA-approved baloxavir treatment mediates improved disease outcomes (survival and viral dissemination) over oseltamivir after lethal intranasal and ocular challenge with A(H5N1)-contaminated cow milk.

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Fig. 1: Effects of OSE and BXA on survival and viral titres in mice inoculated with A/bovine/Ohio/B24OSU-439/2024-contaminated milk.

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Data availability

Data generated in this study are provided in the main paper, figures, extended data figures and tables, and in the Source data files. NGS sequence data are available on figshare at https://doi.org/10.6084/m9.figshare.28422422 (ref. 20). Source data are provided with this paper.

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References

  1. Peacock, T. et al. The global H5N1 influenza panzootic in mammals. Nature 637, 304–313 (2025).

    Article  CAS  PubMed  Google Scholar 

  2. Mostafa, A. et al. Avian influenza A (H5N1) virus in dairy cattle: origin, evolution, and cross-species transmission. mBio https://doi.org/10.1128/mbio.02542-24 (2024).

  3. Centers for Disease Control and Prevention CDC Reports Fourth Human Case of H5 Bird Flu Tied to Dairy Cow Outbreak (CDC Newsroom, 2024); https://www.cdc.gov/media/releases/2024/p-0703-4th-human-case-h5.html

  4. Statement from the Public Health Agency of Canada: Update on Avian Influenza and Risk to Canadians (Public Health Agency of Canada, 2024); https://www.canada.ca/en/public-health/news/2024/11/update-on-avian-influenza-and-risk-to-canadians.html

  5. Centers for Disease Control and Prevention First H5 Bird Flu Death Reported in United States (CDC Newsroom, 2025); https://www.cdc.gov/media/releases/2025/m0106-h5-birdflu-death.html

  6. Hayden, F. G. et al. Baloxavir marboxil for uncomplicated influenza in adults and adolescents. N. Engl. J. Med. 379, 913–923 (2018).

    Article  CAS  PubMed  Google Scholar 

  7. Koszalka, P., Subbarao, K. & Baz, M. Preclinical and clinical developments for combination treatment of influenza. PLoS Pathog. 18, e1010481 (2022).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  8. Shinya, K. et al. Systemic dissemination of H5N1 influenza A viruses in ferrets and hamsters after direct intragastric inoculation. J. Virol. 85, 4673–4678 (2011).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  9. Bauer, L., Benavides, F. F. W., Veldhuis Kroeze, E. J. B., de Wit, E. & van Riel, D. The neuropathogenesis of highly pathogenic avian influenza H5Nx viruses in mammalian species including humans. Trends Neurosci. 46, 953–970 (2023).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  10. Guan, L. et al. Cow’s milk containing avian influenza A(H5N1) virus — heat inactivation and infectivity in mice. N. Engl. J. Med. 391, 87–90 (2024).

    Article  PubMed  Google Scholar 

  11. Fukao, K. et al. Prophylactic treatment with baloxavir protects mice from lethal infection with influenza A and B viruses. Viruses https://doi.org/10.3390/v15112264 (2023).

  12. Taniguchi, K. et al. Characterization of the in vitro and in vivo efficacy of baloxavir marboxil against H5 highly pathogenic avian influenza virus infection. Viruses https://doi.org/10.3390/v14010111 (2022).

  13. Yen, H. L., Monto, A. S., Webster, R. G. & Govorkova, E. A. Virulence may determine the necessary duration and dosage of oseltamivir treatment for highly pathogenic A/Vietnam/1203/04 influenza virus in mice. J. Infect. Dis. 192, 665–672 (2005).

    Article  CAS  PubMed  Google Scholar 

  14. Reed, L. J. & Muench, H. A simple method of estimating fifty percent endpoints. Am. J. Hyg. 27, 493–497 (1938).

    Google Scholar 

  15. Eisfeld, A. J. et al. Pathogenicity and transmissibility of bovine H5N1 influenza virus. Nature 633, 426–432 (2024).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  16. Belser, J. A., Wadford, D. A., Xu, J., Katz, J. M. & Tumpey, T. M. Ocular infection of mice with influenza A (H7) viruses: a site of primary replication and spread to the respiratory tract. J. Virol. 83, 7075–7084 (2009).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  17. WHO Manual on Animal Influenza Diagnosis and Surveillance WHO/CDS/CSR/NCS/2002.5 Rev. 1 (World Health Organization, 2002); https://iris.who.int/bitstream/handle/10665/68026/WHO_CDS_CSR_NCS_2002.5.pdf?sequence=1&isAllowed=y

  18. Potier, M., Mameli, L., Belisle, M., Dallaire, L. & Melancon, S. B. Fluorometric assay of neuraminidase with a sodium (4-methylumbelliferyl-alpha-d-N-acetylneuraminate) substrate. Anal. Biochem. 94, 287–296 (1979).

    Article  CAS  PubMed  Google Scholar 

  19. Patel, M. C. et al. An optimized cell-based assay to assess influenza virus replication by measuring neuraminidase activity and its applications for virological surveillance. Antiviral Res. 208, 105457 (2022).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  20. Jones, J. C. Baloxavir improves disease outcomes in mice after intranasal or ocular infection with Influenza A virus H5N1-contaminated cow’s milk. figshare https://doi.org/10.6084/m9.figshare.28422422 (2025).

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Acknowledgements

We thank St Jude Children’s Research Hospital (SJCRH) animal care staff H. Weinberg, C. Stultz and D. Carey, and the SJCRH Hartwell Center for Bioinformatics for assistance with sequence analysis; the SJCRH research staff or faculty P. Seiler, J. DeBeauchamp, J. Fogo, M. Davis and S. L. Schultz-Cherry for helpful discussion of the paper and data. This study was conducted with federal funds from the National Institute of Allergy and Infectious Diseases, National Institutes of Health, Department of Health and Human Services, contract no. 75N93021C00016 (R.J.W.). The content in this manuscript is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.

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Authors and Affiliations

  1. Department of Host–Microbe Interactions, St. Jude Children’s Research Hospital, Memphis, TN, USA

    Jeremy C. Jones, Konstantin Andreev, Thomas P. Fabrizio, Elena A. Govorkova & Richard J. Webby

  2. Department of Veterinary Preventive Medicine, College of Veterinary Medicine, The Ohio State University, Columbus, OH, USA

    Andrew S. Bowman

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Contributions

J.C.J., K.A., E.A.G., A.S.B. and R.J.W. conceptualized the research project. J.C.J., K.A. and T.P.F. acquired and/or analysed the data. J.C.J. and E.A.G. wrote original drafts, and all other authors reviewed and edited subsequent drafts. Funding was acquired by R.J.W.

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Correspondence to Richard J. Webby.

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The authors declare no competing interests.

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Nature Microbiology thanks Young Ki Choi, Diego Diel and the other, anonymous, reviewer(s) for their contribution to the peer review of this work. Peer reviewer reports are available.

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Extended data

Extended Data Table 1 Deep-sequence analysis of NA protein amino acid substitutions in virus-positive brain or lung tissue
Full size table
Extended Data Table 2 Deep-sequence analysis of PA protein amino acid substitutions in virus-positive brain or lung tissue
Full size table

Extended Data Fig. 1 50% Mouse Lethal Dose (MLD50) of A/bovine/Ohio/B24OSU-439/2024 contaminated milk administered by multiple routes.

Mice (n = 3 or 4 per dilution) were inoculated with the indicated virus-contaminated milk dose in total volume of 50 μL (oral), 30 μL (intranasal), or 10 μL (ocular, 5 μL/eye). Survival was monitored for 14 days post-inoculation. MLD50 values were estimated by method of Reed and Meunch14. Mock inoculated animals received an equal dose of influenza A, M gene real-time PCR negative milk (Ct ≥ 36). The full dilution series was not used for each route.

Extended Data Fig. 2 Effects of OSE and BXA on morbidity in mice inoculated with A/bovine/Ohio/B24OSU-439/2024 contaminated milk.

Mice (n = 8/survival group) were inoculated by the indicated route and treated with OSE or BXA as indicated beginning 24 hpi. Animals were weighed daily to assess morbidity.

Supplementary information

Source data

Source Data Fig. 1

Individual source data, divided into tabs, for main figures/tables and extended figures.

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Jones, J.C., Andreev, K., Fabrizio, T.P. et al. Baloxavir improves disease outcomes in mice after intranasal or ocular infection with Influenza A virus H5N1-contaminated cow’s milk. Nat Microbiol 10, 836–840 (2025). https://doi.org/10.1038/s41564-025-01961-5

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