Merck Animal Health has updated its Prestige line of equine influenza vaccines.
“For the past 10 years, we’ve been monitoring influenza, along with other common infectious upper respiratory diseases, through the Merck Animal Health Biosurveillance Program, a partnership with the University of California, Davis,” said D. Craig Barnett, director of equine veterinary professional services. “It was through this program that we identified and isolated a new highly infectious and relevant equine influenza strain from the 2013 Ocala, Florida, influenza outbreak that impacted a large number of horses from all over the world.
“This strain is now part of our updated line of influenza-containing killed virus vaccines and represents a current, clinically significant strain responsible for a large influenza outbreak in well-vaccinated horses.”
The Prestige line includes Florida ’13 of the clade 1 family and Richmond ’07 of the clade 2 family, Merck reported. The clade 1 family of equine influenza primarily circulates in the United States, while clade 2 predominantly circulates in Europe, the company added.
“Due to the evolutionary changes that occur with equine influenza, known as antigenic drift, influenza-containing vaccines must be updated periodically to ensure protection against current strains of influenza circulating in the field and impacting our horses,” Dr. Barnett said. “And while we have not had any outbreaks of clade 2 in the United States to date, U.S. horses competing internationally should have clade 2 protection on board.”
Influenza vaccination is recommended at six-month intervals for any performance, show or pleasure horses constantly at risk of exposure, including resident horses exposed to traveling horses, Merck stated.