Two animal health organizations to commercialize H5N1 vaccine for dairy cattle

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Elanco Animal Health and Medgene, a South Dakota-based animal health company focusing on vaccine technology, have entered into an agreement which includes the commercialization of a highly pathogenic avian influenza (HPAI) H5N1 vaccine for dairy cattle, developed by Medgene.¹ The partnership comes at a time when bird flu cases are on the rise, with infections observed in humans as well as several wild and domestic mammals, including cats, dogs, raccoons, bears, foxes, and more.^2,3

The vaccine has met all platform technology guidelines requirements from the USDA, according to the company. It is now in the final stages of review for conditional license approval.¹

“Medgene has an established reputation of supporting animal owners and their veterinarians with our USDA-licensed platform technology and bioinformatics software to design transformational vaccines,” Mark Luecke, CEO of Medgene, said in a news release.¹ “With our critically important H5N1 vaccine for dairy cattle in the final stages of approval, we’re excited to partner with Elanco to quickly bring this much needed solution to US dairies.”

Medgene’s vaccine platform technology in cattle received prior approval from the USDA, which accelerated Medgene’s H5N1 vaccine development, according to the company.¹ The company also has existing vaccine manufacturing supply ready for deployment to support the US dairy herd, said Elanco.¹

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Currently entering its fourth year, the H5N1 outbreak has affected 973 dairy herds, with 17 states in the US experiencing outbreaks in dairy cows as of February 21, 2025.³ “The cross-species transmission of the disease into nearly 1,000 dairy herds across the US since March 2024, along with zoonotic transmission to people, shows that more interventions are quickly needed. This virus is prevalent and predicted to persist over time, thus a cattle vaccine will be critical to slow virus spread between birds and cattle,” wrote Elanco in a news release.¹

“As egg prices soar and milk production wanes in infected dairies, the need for new solutions to curb disease spread is evident,” Jeff Simmons, president and CEO of Elanco said.¹ “Elanco is pleased to partner with Medgene to bring customers options to fight this devastating disease and believes this product will become part of a routine vaccination protocol for the US dairy industry. This partnership further strengthens our diverse dairy portfolio and advances our One Health platform of animal health solutions, not only benefitting our dairy customers, but helping curb disease spread for our poultry customers, and working to improve egg prices for consumers.”

Zoetis also has an H5N1 vaccine, for which it received a conditional license in 2016 and a contract award for the USDA’s National Veterinary Stockpile. The vaccine was later utilized by the US Fish & Wildlife Service in 2023 to protect California condors.⁴

RELATED: USDA confirms new avian influenza genotype in dairy cattle

More recently, the USDA issued a conditional license for a vaccine—Avian Influenza Vaccine, H5N2 Subtype, Killed Virus, developed by Zoetis—to protect chickens against the H5N2 subtype of HPAI, a newer strain of HPAI detected in the US in early 2022.⁴ Causing severe disease in birds, HPAI H5N2 has a high mortality rate in these animals. However, this subtype of avian influenza has a lower zoonotic transmission when compared to H5N1, with fewer reports of infection in mammals.⁵

Still, HPAI H5N2 outbreaks in birds have been observed in several countries in the last few decades, including Canada, Mexico, South Africa, Haiti, and the US. In May 2024, Mexico confirmed the first recorded human case of H5N2 in a 59-year-old man with underlying conditions, who later died due to complications. The patient had no history of exposure to poultry or other animals.⁵

Clinical signs of H5N1 in cattle

Fewer than 10% of cows in a herd have shown signs of illness, with the lactating cows being most highly impacted.⁶ Common clinical signs of H5N1 in cows include low appetite and reduced milk production. Abnormal appearance of milk, such as milk that is thickened and/or discolored is another sign of infection.

References

1. Elanco enters agreement with Medgene to commercialize highly pathogenic avian influenza vaccine in dairy cattle. News release. Elanco Animal Health Incorporated. February 22, 2025. Accessed February 27, 2025. https://www.elanco.com/en-us/insights/elanco-enters-agreement-with-medgene-to-commercialize-hpai-vaccine-in-dairy-cattle
2. Bautista-Alejandre A. New study finds cows can transmit avian flu to other mammals. dvm360. August 2, 2024. Accessed February 27, 2025. https://www.dvm360.com/view/new-study-finds-cows-can-transmit-avian-flu-to-other-mammals
3. Current situation: Bird flu in dairy cows. US Centers for Disease Control and Prevention. Accessed February 27, 2025. https://www.cdc.gov/bird-flu/situation-summary/mammals.html#:~:text=In%20recent%20years%2C%20HPAI%20H5N1,such%20as%20tigers%20and%20leopards
4. McCafferty C. USDA issues conditional license for H5N2 vaccination. dvm360. February 17, 2025. Accessed February 27, 2025. https://www.dvm360.com/view/usda-issues-conditional-license-for-h5n2-vaccination
5. Apostolopoulos V, Rodriguez-Morales AJ, Diaz B, Mehta R, Sah R. First confirmed human case of H5N2 virus infection in Mexico: An emerging zoonotic concern. Infezioni in Medicina. 2024;32(3). doi:10.53854/liim-3203-16
6. Avian influenza virus type A (H5N1) in US dairy cattle. American Veterinary Medical Association. February 20, 2025. Accessed February 27, 2025. https://www.avma.org/resources-tools/animal-health-and-welfare/animal-health/avian-influenza/avian-influenza-virus-type-h5n1-us-dairy-cattle#:~:text=On%20March%2025%2C%202024%2C%20the,here%20and%20background%20information%20here.