REDFIELD, Iowa (DTN) -- A researcher at Louisiana State University (LSU) has developed a new vaccine to fight the No. 1 disease causing fatalities in cattle -- bovine respiratory disease (BRD).
BRD can kill up to 8 million calves each year, costing the U.S. cattle industry more than $1 billion. LSU professor of veterinary medicine Shafiqul Chowdhury said the vaccine is safer than other vaccines currently available.
He took bovine herpes virus type 1 (BHV-1) and genetically modified it to provide the protective proteins of other bovine respiratory viruses, including bovine viral diarrhea virus type 1 and 2 and bovine respiratory syncytial virus, to help prevent BRD. This work took Chowdhury 10 years to develop, and he currently has applied for a patent for the vaccine. Once acquired, a commercial company will manufacture the vaccine, as a licensing agreement has already been signed.
It is estimated that 20% of all cattle raised for beef production will require clinical treatment for BRD at some point in their lives, according to Matthew Scott, assistant professor of microbial ecology and infectious disease at Texas A&M College of Veterinary Medicine and Biomedical Sciences. BRD is considered a multifactorial disease complex because several factors play a role in its development, including genetic susceptibility, suppression of the immune system, stress, co-mingling with sick cattle, sudden weather/climate shifts, and being exposed to pathogens.
VACCINE DEVELOPMENT AND BENEFITS
Chowdhury said the way this vaccine was developed, it will be safer than the current cocktails of live vaccines, and the calf mortality rate in vaccinated animals should decrease. The U.S. does not require marker or DIVA (differentiating infected from vaccinated animals) vaccines, which can be distinguished from the virulent field viruses. Current vaccines are not DIVA/marker vaccines, and therefore the vaccine viruses can circulate and be maintained in the cattle population.
Chowdhury's vaccine has no chance of causing spread and circulation of the vaccine virus. This new vaccine is cost-effective since it uses one virus, genetically modified BHV-1, which grows well in cell culture. In current commercial vaccines, individual viruses are grown separately and then mixed.
This vaccine also does not cause abortion, a potential outcome among cows that reach adulthood after being given the commercial vaccine cocktail.
It is hoped that the vaccine will prevent clinical signs of disease, which include high fever, discharge from nose and eyes, coughing, tilted head/ear position, and signs of depression, such as decreased appetite, slow body movement, and unwillingness to stand, according to Scott.
"At birth, calves can receive passive immunity from receiving the proper amount of colostrum," Scott added. "As calves grow, their immunity can be boosted further with vaccines, de-wormers, and adequate nutrition."
Other preventatives of BRD include proper ventilation, minimal pen movements, low-stress handling techniques, clean bedding, and access to feed and water.
Jennifer Carrico can be reached at jennifer.carrico@dtn.com
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