Infectious bronchitis virus causes devastating losses to the poultry industry but scientists are now developing a new way to vaccinate chicks against the disease — one that can be delivered while they are still in their egg. Researchers have used a “reverse genetic” system to produce a new vaccine strain which is safe to deliver to chicks while they are still in the egg, making it more effective than current vaccines.
A pre-hatching prototype vaccine virus which provides immunity to IBV has been developed by scientists at the Institute for Animal Health (IAH) and vaccine company Intervet UK. It can be delivered to chicks still in the egg (in-ovo) using robotic ‘vaccinators’.
IBV is the worst infectious disease in terms of economic loss to the UK poultry industry. Infection can lead to severe respiratory disease, dramatically reduce egg production and affect the quality and hatchability of eggs.
The researchers, funded by the Biotechnology and Biological Sciences Research Council (BBSRC), Department of the Environment, Food and Rural Affairs (Defra) and Intervet UK, used a ‘reverse genetic’ system to produce new vaccine strains. Existing strains, which are usually delivered by less efficient spray or drinking water dosage, can prevent chicks hatching if delivered in the egg.
The scientists have extracted a so-called spike protein from a pathogenic virus strain which triggers an immune response, and incorporated it into a harmless non-pathogenic strain. Dr Paul Britton, Head of the Coronavirus Group at IAH Compton, explained, “This hybrid virus was able to induce immunity when inoculated before hatching. When hatched chicks were exposed to the virulent M41 strain, we observed protection rates of up to 100 percent. With the UK poultry industry sustaining losses of ?23.6M a year to infectious bronchitis virus we hope that our research could have a real impact on improving yields for UK farmers.”
“We are currently trying to modify the vaccine further, in collaboration with Intervet, to make it suitable for commercial use,” said Dr Britton.
Professor Julia Goodfellow, Chief Executive of BBSRC, said: “BBSRC research into endemic UK animal disease has the potential to save UK farmers and consumers millions of pounds each year. IBV is one of the severe animal diseases that BBSRC supports research into, and the work at the Institute for Animal Health shows real promise in delivering tangible improvements on the farm.”