In this episode, we're breaking down how bird flu has spilled over from wild birds into dairy cow herds, impacting the milk we drink. Join me, Caroline Zeiss, as we explore why this is happening, how we could control it, and what it tells us about the increased risk of bird flu spreading to humans. "The VirusDiaries" is written and recorded by me in Guilford, CT. I’m a Professor of Comparative Medicine at Yale University School of Medicine. Just to be clear, all views expressed in this podcast are mine and do not reflect those of Yale University.

References

Currentnews

https://abcnews.go.com/Health/bird-flu-continuing-spread-animals-us/story?id=121481973

B3.13avian flu in dairy cows

CasertaLC et al., Spillover of highly pathogenic avian influenza H5N1 virus to dairycattle. Nature. 2024 Oct;634(8034):669-676.

Dholakia,V et al., Polymerase mutations underlie early adaptation of H5N1 influenzavirus to dairy cattle and other mammals. bioRxiv 2025.01.06.631435; doi: https://doi.org/10.1101/2025.01.06.631435

Ting-HuiLin et al., A single mutation in bovine influenza H5N1 hemagglutinin switchesspecificity to human receptors.Science386,1128-1134(2024).

Baker,A.L., Arruda, B., Palmer, M.V. et al. Dairy cows inoculated with highlypathogenic avian influenza virus H5N1. Nature 637, 913–920 (2025).

Halwe,N.J., Cool, K., Breithaupt, A. et al. H5N1 clade 2.3.4.4b dynamics inexperimentally infected calves and cows. Nature 637, 903–912 (2025).

FacciuoloA, et al., Dairy cows develop protective immunity against reinfection withbovine H5N1 influenza virus. Nat Microbiol. 2025 Apr 17. doi:10.1038/s41564-025-01998-6.

D1.1avian flu in dairy cows

https://www.aphis.usda.gov/sites/default/files/dairy-cattle-hpai-tech-brief.pdf

https://www.cdc.gov/media/releases/2025/m0106-h5-birdflu-death.html

Vaccinationin dairy cows

https://www.science.org/content/article/companies-start-work-bird-flu-vaccines-cows-despite-major-hurdles

https://www.nmpf.org/nmpf-pushes-for-vaccine-as-usda-unveils-bird-flu-plan-dairy-cattle/

https://www.nmpf.org/dairy-groups-applaud-administration-vaccine-support-thank-usda-for-plan/

https://www.thinkglobalhealth.org/article/time-act-new-bird-flu-spillovers

https://www.cdfa.ca.gov/AHFSS/Animal_Health/HPAI.html

Wastewatertesting

TiszaMJ, Hanson BM, Clark JR, Wang L, Payne K, Ross MC, Mena KD, Gitter A, JavornikCregeen SJ, Cormier J, Avadhanula V, Terwilliger A, Balliew J, Wu F, Rios J,Deegan J, Piedra PA, Petrosino JF, Boerwinkle E, Maresso AW. Sequencing-BasedDetection of Avian Influenza A(H5N1) Virus in Wastewater in Ten Cities. N EnglJ Med. 2024 Sep 26;391(12):1157-1159.

Government  funding to control H5N1

https://www.theguardian.com/us-news/2025/jan/15/biden-administration-bird-flu-funding

https://public3.pagefreezer.com/browse/HHS.gov/21-01-2025T07:38/https://www.hhs.gov/about/news/2025/01/03/hhs-awards-306-million-avian-flu-monitoring-and-preparedness-funding.html

https://www.usda.gov/about-usda/news/press-releases/2025/02/26/usda-invests-1-billion-combat-avian-flu-and-reduce-egg-prices

https://www.aphis.usda.gov/news/agency-announcements/usda-announces-next-steps-effort-support-fight-against-avian-influenza