Development could lead to vaccines that target multiple avian diseases
A new recombinant vaccine that is effective against Marek’s disease (MD) and infectious bursal disease (IBD) has been developed by researchers at the Pirbright Institute.
Most poultry vaccines use a modified herpesvirus of turkeys (HVT) to induce protection against poultry diseases, including MD and IDB. When used alone, these vaccines are highly effective. However, they often fail to activate sufficient immune responses when combined with other HVT vaccines.
The new vaccine uses a viral vector called SB-1, which has a long history of working as a combined vaccine with HVT. By genetically modifying the SB-1 strain, the team at Pirbright were able to insert protective genes from the IBD virus and confirm that the resulting virus could provide immunity against both diseases.
Writing in npj Vaccines, the researchers show the vaccine could provide immunity against IBDV infection at the same level as HVT vectored vaccines. With further advantage of complementing HVT vectored vaccines, the new SB-1 vector offers potential for developing commercial vaccines capable of giving simultaneous protection against multiple avian diseases.
“This development allows us to engineer vaccines that target multiple diseases which complement existing commercial vaccines,” explained Professor Venu Nair, head of the Viral Oncogenesis group. “The technique also offers scope for us to include other virus genes such as from avian influenza and Newcastle disease in the SB-1 vaccine, enabling us to protect against even more diseases in a single dose”.
MD and IBD are both highly infectious diseases and associated with high mortality rates. As such, they remain a constant threat to the productivity if the worldwide poultry industry.