Poultry respiratory diseases, such as infectious bronchitis and Newcastle disease, require proactive approaches to vaccination.
“Because they are RNA viruses, there is no treatment option, so we have to control them,” said Dr. Roy Jacob, key account veterinarian for Boehringer Ingelheim Poultry Division. “It’s more challenging when it comes to infectious bronchitis.”
A coronavirus, infectious bronchitis can evolve very rapidly, making control strategies an ever-moving target. New variants or strains of the virus seem to emerge every five to eight years.
“It can mutate and produce new serotypes or a new variant every few years. That makes it challenging, and we need to be on top of vaccination, biosecurity and prevention because there is no treatment,” he added.
Newcastle disease affects the digestive, nervous and respiratory systems of poultry. Many birds infected with the contagious disease die without showing any clinical signs, according to the U.S. Department of Agriculture (USDA) Animal and Plant Health Inspection Service (APHIS). The virus has been mostly eradicated in the U.S. but can be endemic to other parts of the world.
“We are fortunate that we don’t have as much of a disease pressure as far as Newcastle disease is concerned. But there is already some low virulence present in some parts of the U.S., so it’s still a concern,” Jacob explained.
Proactive respiratory disease vaccine programs
Because Newcastle disease and infectious bronchitis mutate so frequently, it’s important for producers to work closely with their veterinary team to ensure that the vaccine used is a close match to common strains of the viruses. Otherwise, a vaccination program won’t be as effective.
“Make sure you have a pretty good understanding of the challenge strains you’re seeing in the field and adapt your vaccination strategy accordingly. No one vaccine fits all,” Jacob said.
In addition, a lot of laboratories now offer programs that provide a quantitative assessment of the effectiveness of vaccine programs.