Infectious bronchitis virus (IBV) is highly contagious disease and responsible for major economic losses to the poultry industry worldwide. Infected chickens experience weight loss, decreased egg production and impaired egg quality, as well as being left vulnerable to other diseases, according to an announcement from The Roslin Institute in the U.K.
Current vaccines protect against some strains of the virus, but not others, and these failures are possibly linked to differences in the spike protein — the protein that enables the virus to attach to and enter cells — between strains of the virus, researchers said.
Research is needed to develop new vaccines that protect against multiple strains of IBV.
"There is a real need to develop new vaccines against infectious bronchitis that protect against multiple strains and offer rapid responses. We are trying to make a vaccine that offers broad protection, but further research is needed to develop a more robust vaccine," said professor Lonneke Vervelde with The Roslin Institute.
Researchers at The Roslin Institute and the Pirbright Institute tested a new approach using a specialist type of vaccine, known as recombinant virus vaccines. These vaccines use harmless or weak versions of a virus or bacteria to introduce microbes into cells in the body, the announcement said.
In this instance, experts used recombinant viruses with different spike proteins as vaccines to build two versions of a harmless virus.
Results show that the vaccine offered partial protection against IBV, but further research is needed to develop a more robust vaccine, Roslin said.
Researchers said these recombinant vaccines have the potential to be more cost effective and respond to emerging new virus strains. The next step will be to make a vaccine that remains harmless but induces a stronger immune response. The research has been published in the Journal of Virology.
Pirbright Institute researcher Dr. Erica Bickerton said, "Our research hopes to develop more cost-effective and efficient commercial vaccines that are capable of protecting chickens against this serious disease."