Are We Vaccinating for the Right BRD Viruses?

Project Title

Rapid Characterization of the Viral Microbiome in Arriving Feedlot Calves to Inform Vaccine Gaps and Risk Assessment for Bovine Respiratory Disease


Dr. Cheryl Waldner DVM (WCVM)

Yanyun Huang, Maodong Zhang and Anatoliy Trokhymchuk (Prairie Diagnostic Services) Claire Freeman, Janet Hill, John Campbell, and John A. Ellis (University of Saskatchewan Western College of Veterinary Medicine) Matthew Links (University of Saskatchewan) Simon Otto (University of Alberta School of Public Health) Volker Gerdts (Vaccine and Infectious Disease Organization)

Status Project Code
In progress. Results expected in April, 2024 ANH.20.20


Bovine respiratory disease starts when stress suppresses the immune system and allows viruses like BVDV, BHV-1, BRSV and PI3 to infect the respiratory tract. These viral infections allow bacteria like Mannheimia, Pasteurella, Histophilus and Mycoplasma to move from the upper respiratory tract and set up infections in the lower respiratory tract (lungs). Preventing the initial viral infection (through vaccination) is key to reducing the risk of BRD. There are vaccines against the four main respiratory viruses , but there may be more viruses involved that we aren’t aware of. Current virus detection techniques only look for known strains of known viruses, so we may be missing other viruses altogether. Metagenomic sequencing provides a way around this, and is a step towards automated, rapid testing.


  • Describe respiratory viruses in feedlot calves at arrival to identify vaccine gaps (vaccine use prior to arrival and need for new vaccines),
  • Determine to what extent the virome predisposes calves to the development of bacterial infection or clinical BRD, and
  • Advance rapid metagenomic sequencing and bioinformatic protocols for the diagnosis of viral BRD in feedlot calves.

What they will do

This project will assay and sequence viruses in 400 high risk calves arriving at the Livestock and Forage Center of Excellence research feedlot. They will study associations between which viruses are present with which bacteria, and which viruses are most often associated with different BRD outcomes. They will compare the viruses they find to the viruses the vaccines protect against.


This study will help identify which respiratory viruses are being most effectively vaccinated against, which vaccines need better uptake, and which new vaccines need to be developed. This will also contribute to rapid diagnostics that could help inform BRD risk classifications and BRD treatment and management protocols.