They say this approach could lead to a reduction in the number of vaccines that need to be administered to each bird.
Vaccines that target multiple diseases are in high demand due to the many viruses that can circulate simultaneously in flocks. Protecting against the most dangerous diseases with one vaccine could reduce overall vaccination costs for poultry producers and decrease the number of times that birds need to be handled.
The researchers demonstrated that a gene editing system called CRISPR/cas9 can be used to insert a gene of the IBD virus into the currently used Marek’s disease vaccine virus. The added genetic material protects poultry against IBD in addition to the protection already offered by the Marek’s disease vaccine, meaning that bird owners would only need to use one vaccine instead of two.
Other vaccines generated by conventional methods can achieve a similar result, but by using the CRISPR/cas9 system the Pirbright researchers say they have been able to insert the IBD gene far more quickly, easily and accurately than the methods that have been used before. This will significantly reduce the time needed to generate new vaccines.
Professor Venugopal Nair, joint leader of the research at Pirbright said: "The method we have created with CRISPR/cas9 really increases the scope of how we edit the Marek’s disease vaccine to include other virus components. Now we have shown that the gene-edited vaccine protects against both Marek’s disease and IBD, we are looking at inserting more genes from other viruses."
The team intend to generate a vaccine that will be able to protect against multiple avian diseases and will next target two high consequence poultry viruses - avian influenza virus and the Newcastle disease virus. The flexibility of the new method also means that as the viruses evolve, the vaccine virus can be easily edited to include new genes which protect against emerging strains.
The Pirbright Institute says there has been huge commercial interest in using this technology to develop novel vaccines, so it intends to partner vaccine manufacturing companies to bring CRISPR/cas9 edited vaccines to market.
This scientific paper can be found in the Vaccine journal and was funded by the Biotechnology and Biological Sciences Research Council (BBSRC); grant numbers BB/P016472/1 BB/L014262/1.
Photo: Cells infected with the Marek's disease vaccine virus, HVT, (green) expressing the inserted infectious bursal disease virus gene, VP2 (red). Cell nuclei are shown in blue. © Dr Na Tang, The Pirbright Institute 2018.
PS: Whilst you're here, take a moment to see our latest job opportunities for vets.