H5N1 Cattle Vaccine
- University of Nebraska–Lincoln researchers said April 23 they developed an H5N1 vaccine candidate that protected dairy calves and mice in preclinical tests, targeting bird flu after the virus spilled into U.S. cattle. - The calves were vaccinated at one week old with intramuscular and intranasal doses, then boosted four weeks later; in separate mouse tests, vaccinated animals were fully protected from lethal infection. - No H5N1 vaccine is licensed for cattle, even after the 2024 dairy-cattle spillover and worker illnesses. (eurekalert.org)
Bird flu is a virus that usually spreads in birds, but in 2024 one H5N1 strain jumped into U.S. dairy cattle. University of Nebraska–Lincoln researchers now say an experimental cattle vaccine protected dairy calves and mice in preclinical tests. (eurekalert.org) The team, led by virologist Eric Weaver at the Nebraska Center for Virology, announced the results on April 23. The work is slated for publication in *npj Vaccines*. (eurekalert.org) (phys.org) Vaccines can train the body in two places: the bloodstream, which helps stop severe illness, and the nose and airways, which can help block spread. This candidate was built to do both. (eurekalert.org) The calves got the vaccine at one week of age through two routes at once: an intramuscular shot and an intranasal dose. They received a booster four weeks later. (eurekalert.org) In separate mouse experiments, vaccinated animals were fully protected against lethal infection from multiple H5N1 strains. In calves, the researchers reported strong immune responses and protection against severe disease. (eurekalert.org) (phys.org) That delivery strategy matches how this virus behaves in cattle. Weaver said the shot in muscle is meant to limit spread through the body, while the nasal dose is meant to reduce animal-to-animal transmission. (eurekalert.org) The timing matters because there is still no licensed H5N1 vaccine for cattle. The Nebraska team started calf testing in early 2025 after the dairy outbreak kept expanding instead of fading out. (eurekalert.org) H5N1 has already forced the culling of more than 166 million commercial poultry birds in the United States since 2022. After the virus moved into dairy cattle in 2024, about 70 farm workers with close exposure became ill, according to the university release. (eurekalert.org) Weaver is now seeking funding and industry partners to push the vaccine into further evaluation, including a possible multispecies version. He said the goal is a platform that could protect “the farm and the farmer.” (eurekalert.org) For now, the result is still preclinical, not a licensed product. But it gives cattle producers and animal-health officials a concrete vaccine design to test as H5N1 keeps circulating across species. (eurekalert.org)
