If H5N1 were on a soccer team, as one expert described it, it just might be able to score a goal: human-to-human transmission.
With each mammal that becomes infected with H5N1 avian influenza virus, the concern for a human pandemic grows, especially since it has appeared in dairy cows because these animals do not normally get influenza (Viruses 2019;11[6]:561).
In fact, it was an astute veterinarian, Barb Petersen, DVM, who identified H5N1 in U.S. dairy cows in 2024 after ruling out other causes of the signs she was seeing in her patients. Dr. Petersen owns and operates Sunrise Veterinary Service, in the Texas Panhandle, which serves about 40,000 dairy cattle.