New Vaccine Protects Cattle from Bovine Anaplasmosis

Mizzou researcher Roman Ganta created the first effective vaccine proven to protect cattle from the tick-borne disease.

Reprinted with permission by the University of Missouri

University of Missouri researchers are working to develop the first-ever vaccine proven to protect cattle from a devastating tick-borne cattle disease: bovine anaplasmosis. Bovine anaplasmosis – which is common in the state – infects the red blood cells of cattle and causes hundreds of millions of dollars in economic losses nationwide each year and nearly $1 billion in losses worldwide, primarily due to reduced cattle production, treatment costs and deaths.

Roman Ganta, a McKee endowed professor in Mizzou’s College of Veterinary Medicine and a Bond Life Sciences Center researcher, led the study that created the new vaccine. The work involved genetically modifying the pathogen Anaplasma marginale – which causes bovine anaplasmosis – in a lab. By deleting a specific gene and then injecting the modified pathogen into cattle, the vaccinated cattle were successfully immunized against the disease.

“I often receive calls from cattle producers who are excited about our research and want to know how soon they can get the vaccine,” Ganta said. “There is currently no effective, widely available, vaccine for the disease, and cattle farmers are very worried about the disease harming or killing their cattle. We want to help farmers in Missouri and around the world and are working hard to come up with a viable solution.”

Moving the needle forward

Ganta has been researching molecular genetics and vector-borne diseases for more than 30 years. His research builds on a long history of advances in battling bovine anaplasmosis at the university.

“Missouri is a hotbed for tick-borne diseases, and bovine anaplasmosis causes massive economic losses both here in Missouri and around the world,” Ganta said. “Mizzou has already made substantial contributions to protecting cattle against ticks. For example, many farmers currently give their cattle an antibiotic called chlortetracycline, which was first discovered at Mizzou’s Sanborn Field in 1945. While effective, that medicine doesn’t fully eliminate the infection, so this new vaccine is an innovative step forward to fully eliminate the infection.”

Ganta said the new vaccine has been proven to give immunized cattle protection against bovine anaplasmosis for at least a month, and he and his team are eager to conduct additional research to determine how long the genetically modified pathogen can provide immunity for cattle. Ganta is also collaborating with industry partners to discuss future distribution of the new vaccine – which has been patented – to cattle producers.

“The genetically modified live vaccine offers protective immunity against wild-type Anaplasma marginale tick-transmission challenge” was published recently in Vaccine.

A 2021 Mizzou study found recent increases in both the number and severity of tick-borne diseases in the Midwest, particularly in the humid climates of Missouri, Kansas, Oklahoma and Arkansas. The documentation of what, when and where ticks are present helps public health officials better understand the threat of tick-borne diseases to people, pets and livestock.

Key Points (1)

• Anaplasmosis is a tickborne disease of ruminants caused by intracellular bacteria that infect red blood cells, causing fever and anemia.
• Tetracycline antibiotics and imidocarb are currently used for treatment. Infections may be completely cleared by treatment with these drugs, and the cattle then remain immune to severe anaplasmosis
  for at least 8 months.
• Calves are more resistant to disease (although not infection) than older cattle.

1 Tabor, A.E. (2024) Anaplasmosis in Ruminants. Merck Veterinary Manual.

Photo credit: istockphoto.com/Kateryna Kukota