UTMB When highly pathogenic avian influenza A (H5N1) was first confirmed in U.S. dairy cattle in early 2024, it challenged assumptions about which species are at risk from “bird flu”. Follow-up investigations show that this virus can spread efficiently within and between dairy herds and occasionally infect other mammals, including cats and humans [1]. Few health professionals believed that humans were being infected with avian influenza A (H5N1) during these outbreaks.
In a new manuscript published in the journal Influenza and Other Respiratory Viruses by UTMB One Health collaborators (Dr. Ismaila Shittu first author), Low Levels of Neutralizing Antibodies to Influenza A (H5N1) and D Viruses Among Cattle and Cattle Workers on U.S. Farms, 2024–2025, adds important information to this evolving story [2]. The researchers tested cattle and cattle worker sera against the H5N1 influenza A virus, which is associated with the current U.S. dairy cattle epizootic, and Influenza D virus, which is a newly recognized virus known to circulate in cattle populations. The researchers measured neutralizing antibodies in cattle and cattle worker sera. These assays tell scientists if the cattle or cattle workers have evidence of previous infection by looking for evidence of blocking viral infections into susceptible cells in the laboratory [3].