The dairy industry is one step closer to having a vaccine available for highly pathogenic avian influenza (H5N1). Last week, Secretary of Agriculture Tom Vilsack announced that USDA has authorized the first field trial of a vaccine for the virus.

Several groups have been working on developing a vaccine for this novel concern that was first confirmed in March, he continued. All trials have so far been conducted in contained research facilities, such as the one at the National Animal Disease Research Center, a USDA facility in Ames, Iowa. This approval will allow potential H5N1 vaccines to instead be tested in environments that more closely resemble today’s dairy farms.

It is an important development in equipping dairy farmers with a plan of attack against the disease. Since March, 193 cases have been confirmed in 13 states. Fortunately, spread has slowed this summer, with just 20 new cases in five states confirmed in the last month.

While cows that contract the disease have not been as severely impacted as poultry that do, milk production and feed intake are affected, leading impacted herds to cull cattle even after they recover due to lingering effects. There are also concerns about the disease spreading to humans after a handful of farm workers who have been around sick cows experienced mild disease symptoms.

No vaccines against the disease have been developed for poultry. Vilsack expressed optimism that with information from a field trial in dairy cattle, a vaccine that is safe and effective could be developed in the near future.

Research has been crucial because the movement of the virus to dairy cattle was not expected. As this timeline from the Centers for Disease Control and Prevention (CDC) indicates, forms of the highly pathogenic avian influenza virus have been detected in multiple species around the world for more than a century. There is much still unknown about how it spreads and mutates. In dairy cattle, it appears to be developing in the udder, which contains many potential receptors for the virus. This is in contrast to how influenza viruses typically infect the respiratory system.

Until a vaccine is tested and approved, a dairy farmer’s best protection against the disease is to continue taking biosecurity measures to prevent new contaminants from entering the farm.