Missouri and Kentucky have joined the list of states approved by the USDA for sales of an anaplasmosis vaccine marketed by University Products LLC of Baton Rouge, La.

The vaccine is the only "killed" vaccine available to prevent anaplasmosis, a disease that costs U.S. cattle and dairy producers an estimated $300 million a year.

No USDA-licensed biologic facility currently exists in Louisiana, said E. Gene Luther, although he expects to have a laboratory approved to produce the vaccine in Louisiana within a year. The vaccine currently is produced in an LSU AgCenter laboratory in Baton Rouge.

The company is less than a month away from completing the final test needed to start the licensing procedure. With the license and approved laboratory, the vaccine could be available worldwide.

The vaccine is now approved for sale in Arkansas, California, Florida, Indiana, Illinois, Iowa, Kansas, Kentucky, Louisiana, Mississippi, Missouri, Nevada, Oklahoma, Oregon, Tennessee, Texas, Wisconsin and Puerto Rico.

The University Products vaccine is a “killed vaccine,” which means it uses the dead organism to create immunity in cattle. When the vaccine is injected, the animal’s immune system creates antibodies and “cell-mediated immunity,” which protects the animal from the severe clinical disease of anaplasmosis, Luther said.

Anaplasmosis, a disease caused by an intracellular microorganism, causes red blood cells in cattle to be removed from circulation and destroyed. It occurs primarily in warm tropical and subtropical areas. Once confined to the Gulf and West Coast in the United States, it has spread to other parts of the country with the movement and distribution of cattle.

“It’s probably in every state of the union,” Luther said. “It has steadily moved north.”

Clinical signs are severe and profound anemia, and the mortality rate escalates as animals become older and have a higher need for oxygen. The greatest problems are with mature bulls and pregnant and nursing cows.

The organism is spread by ticks, which are biological vectors because they actually carry the organism, and by horseflies, which are mechanical vectors because they can move the organism from one animal to another although they don’t carry the disease themselves.

After an animal survives a natural case of anaplasmosis, its immune system will protect against the organism for the life of the animal. Cattle that recover from anaplasmosis, however, are carriers that act as a reservoir of infection and can be a source to spread the disease to susceptible cows.

“The vaccine has given good protection in areas where it has been used,” Luther said. “We have marketed hundreds of thousands of doses, and it is available from veterinarians in approved states.”

More information is available online here.