An LSU researcher has developed a new vaccine against bovine respiratory disease and related illnesses that kill around 8 million calves each year and cost the U.S. cattle industry more than $1 billion.

Most cattle producers now use a commercially available modified live BRD vaccine containing several live viruses (a cocktail) to protect their herds. Still, the diseases kill more than one out of every five calves.

“Our vaccine is safer for calves and far more effective than the vaccine cocktail,” said Dr. Shafiqul Chowdhury, a professor of veterinary medicine.

Chowdhury took bovine herpes virus type 1 (BHV-1) and genetically modified it to provide the protective proteins of other bovine respiratory viruses -- bovine viral diarrhea virus type 1 & 2 (BVDV 1more & 2), and bovine respiratory syncytial virus (BRSV) -- to prevent bovine respiratory disease.

LSU Vice President of Research & Economic Development Robert Twilley said research that leads to new tools like Dr. Chowdhury’s vaccine is one of the pillars of LSU’s Scholarship First Agenda, which advances agriculture, biomedicine, coastal protection, defense and energy.

“Global population growth and environmental changes mean we must increase the amount of food we produce,” Twilley said. “This LSU-developed vaccine will help protect the world’s food supply and improve outcomes for cattle producers in Louisiana and nationwide.”

Chowdhury said the calf mortality rate in vaccinated animals is just one area where the current vaccine cocktail falls short.

The United States does not require marker or DIVA (Differentiating Infected from Vaccinated Animals) vaccines, which can be distinguished from the virulent field viruses. The current vaccine cocktail is not a DIVA/marker vaccine. Vaccine viruses can therefore circulate and be maintained in the cattle population. They may change over time and regain the ability to cause disease.

Cattle producers have also reported spontaneous abortions and bovine respiratory disease in vaccinated animals. Variants of the live vaccine viruses are thought to be the cause. The lack of markers in the vaccine cocktail makes it impossible to distinguish the vaccine viruses from the disease-causing viruses.

With Chowdhury’s vaccine, there is no chance for the vaccine virus to spread and circulate in the cattle population, he said.

Chowdhury’s vaccine offers other advantages:

• It’s cost-effective. It uses one virus, genetically engineered BHV-1, which grows well in cell culture. In the commercial cocktail vaccine, individual viruses are grown separately and then mixed. Each vaccine batch requires extensive quality control. BRSV, the virus, grows poorly in cell culture with a meager yield.
• It does not cause abortion, a potential outcome among cows that reach adulthood after being given the commercial vaccine cocktail.

Chowdhury has applied for a patent for the vaccine, with the help of the Office of Innovation & Technology Commercialization, part of the LSU Office of Innovation & Ecosystem Development. Chowdhury has already been awarded several U.S. and international patents. He has several additional patents pending.

“Dr. Chowdhury’s vaccines could be a game-changer for the cattle industry, and we couldn’t be more excited to support this kind of groundbreaking research,” Twilley said. 

Source: Louisiana State University