How a Newly Developed Vaccine Provides Tick Protection for Livestock

Ticks are a significant threat to livestock worldwide. Not only are they carriers for disease causing agents, but they also create economic losses due to illness-related issues like poor weight gain, skin damage, reduced milk and meat production and secondary infections.

The transmission of harmful pathogens, such as Anaplasma marginale — the bacterium that results in bovine anaplasmosis disease — causes further problems, wreaking health havoc on herds across the globe.

To address this issue, Dr. Roman Ganta, a Curators’ distinguished professor and McKee endowed professor at the University of Missouri’s College of Veterinary Medicine, and a Bond Life Sciences Center researcher, led a study to develop a groundbreaking solution.

Development of a Groundbreaking Vaccine

Dr. Ganta’s research team at University of Missouri are working to develop and distribute the world’s first-ever vaccine aimed at preventing tick-borne illnesses in livestock.

The new vaccine has been proven to protect cattle from the tick-borne cattle disease known as bovine anaplasmosis. This devastating livestock illness infects the red blood cells of cattle, causing severe infection. Symptoms of the disease include fever, lethargy, reduced milk production and weight loss just to name a few.

“Bovine anaplasmosis is prevalent in cattle worldwide, causing mass devastation,” Ganta said. “This novel approach is the best approach to solving the problem. If we can take this vaccine to the farmers and they can use it as a solution, they can improve the quality of their meat production and prevent massive economic losses.”

To develop the vaccine, Ganta and his team created a version of the bacterium, which is no longer causing the disease, but gives strong immunity protection. The team deleted a specific gene identified as essential for the pathogen virulence, then injected the modified pathogen into cattle. The vaccinated animals proved to be successfully immunized against bovine anaplasmosis when assessed one month after vaccination.

“The infection itself cannot be prevented, but we can stop it from leading to serious outcomes for animals.”

Vaccine Timeline

Currently, the vaccine is not commercially available. Ganta and technology transfer offices of University of Missouri and Kansas State University (where the research was initiated) are collaborating with an industrial partner in hopes of making it widely available to farmers in the next four to six years.

“There’s a large interest, not just in the U.S., but throughout the world,” Ganta said. “Interest in this vaccine reaches as far as Israel, Brazil, the U.K. and even in South Africa. There is a serious tick problem in the cattle industry, creating high demand for the vaccine.”

Common Livestock Ticks

Certain tick species are responsible for the transmission and spread of bovine anaplasmosis. It’s important for farmers and livestock owners to recognize these pests so they can act quickly should an infestation occur.

While adult ticks tend to cause the most harm to livestock, young nymphs can also become problematic.

The following are common tick species known to carry and transmit wild-type Anaplasma marginale:

American Dog Tick or Wood Tick (Dermacentor variabilis)

This well-known hard tick species is known for spreading bovine anaplasmosis in addition to Rocky Mountain spotted fever among dogs and humans.

The American dog tick is found predominantly in the United States, east of the Rocky Mountains.

Rocky Mountain Wood Tick (Dermacentor andersoni)

Another primary vector of Anaplasma marginale in the United States, the Rocky Mountain wood tick is a large reddish-brown or gray-brown tick that can become problematic on cattle farms.

Issues may include, but are not limited to, ibovine anaplasmosis, tick paralysis and even death. This species is commonly found in southwestern Canada and in the Rocky Mountain region in the northwestern portion of the United States.

According to Dr. Ganta, tick-borne illnesses reach far beyond the United States, creating substantial demand for solutions, including the development of the new and effective vaccine.

Winter Tick or Moose Tick (Dermacentor albipictus)

Winter ticks are a common nuisance to domestic livestock, such as cattle. This tick can transmit Anaplasma marginale, which causes the pathogen anaplasmosis. It is considered a “one-host tick,” meaning they feed on a single host throughout the entirety of its life cycle.

This tick species lives in temperate areas across North America.

Tips to Prevent Tick-Borne Diseases

While the vaccine is still under development, there are several measures farmers can take to control tick populations and prevent disease spread.

Monitor New Herd Animals

According to Dr. Ganta, outbreaks occur most often in new animals introduced into an existing herd.

“The new animals may bring a tick-borne disease, infecting the existing animals. Established herds could be naive to bovine anaplasmosis positive, ultimately causing an outbreak to occur,” he explained.

In this case, Ganta advises farmers to closely monitor any new animals carefully for symptoms of the disease. He also stresses the importance of consulting a veterinarian who can assess, monitor and treat infections.

Chemical Applications

Farmers can control tick populations with the use of various chemical agents, known as acaricides, applied to cattle. Common options include organophosphates, pyrethroids and amidine amitraz. Although highly effective, overuse of such chemical agents can create resistance in tick populations. It’s important to rotate acaricides routinely.

Note: Before applying any chemical agent to a herd, consult a veterinarian or local extension office for approved products in your area. Always follow label instructions regarding proper dosage and frequency of treatment.

Pasture & Environmental Maintenance

Regular pasture and farm maintenance can make a big difference in controlling tick populations. Consider limiting livestock access to wooded areas and keeping grasses mowed. This is especially important along fence lines and tree-lined edges where shaded areas provide habitat for ticks.

Natural pest control methods may also be beneficial. Use of integrated pest management, natural acaricides and plant extracts such as essential oils, have shown promising results.

Also consider minimizing or removing leaf litter and other heavy vegetation found around pastureland. And, if possible, give each animal an in-depth look over. Check areas of the body that tend to carry ticks such as the ears, neck and chest.

Future Global Impact

As Ganta looks to the future, he says the most rewarding outcomes are yet to come.

“The prevalence of tick-borne diseases in livestock globally is huge. My hope is that this vaccine will be used widely, starting in Missouri and expanding to other states and well beyond.”