New adjuvanted recombinant vaccine technology enhanced the protective immune response of broilers against infectious laryngotracheitis (ILT).
“These molecular adjuvants are showing promising results,” said Dr. Ravi Kulkarni, assistant professor, Department of Population Health and Pathobiology, North Carolina State University College of Veterinary Medicine.
ILT is a highly contagious respiratory disease in poultry. After recovery, birds become carriers for the disease, making infection of flock mates likely and reinfection can occur under stressful conditions. Currently, there are two ways to vaccinate against ILT in broiler chickens.
The CEO form, a live attenuated vaccine, is highly effective. However, it can cause increased virulence of the virus through bird-to-bird spread, which can result in severe clinical disease with mortality.
Conversely, the recombinant vaccine types on the market effectively reduce clinical disease but have poor immunogenicity/protection and delayed onset of immunity.
The research made possible in part by Mountaire Corporation and proceeds from the International Poultry Expo, part of International Production & Processing Expo (IPPE), sought to develop and test a better, more effective recombinant vaccine against ILT.
Understanding immune enhancing pathways
His research focuses on using synthetic adjuvant molecules that bind to the toll-like receptors in the broiler immune system to artificially induce an immune response against ILT.
“The whole idea is what if I can take these molecules and then add them to recombinant ILT vaccines, give them in ovo and then start assessing if we can heighten the immune response to protect against an ILT challenge,” Kulkarni said.
In experiments, chicks given the vaccine displayed enhanced immunogenicity against ILT when challenged with the virus. The researchers have already published the initial results of trials testing immune response and overall safety of the new vaccine technology in day-old chicks in Vaccines journal.
The technology is designed to be easily modifiable for use against other infectious agents, such as infectious bronchitis, necrotic enteritis and coccidiosis.
