January 21, 2020

Scientists from Pirbright Institute develop bird flu and Marek's disease vaccine

Scientists at the Pirbright Institute in England have developed a vaccine that protects birds against both Marek's disease and avian influenza, also called bird flu.

The vaccine was developed using genetic engineering, a process that is faster and more efficient than previous methods, allowing poultry vaccine producers to rapidly update vaccine strains to keep up with virus evolution, according to the Pirbright Institute.

The scientists used the gene-editing tool CRISPR/Cas9 to insert an avian influenza gene into the turkey herpesvirus (HVT) that is used in Marek's disease vaccines.

"The genetic engineering process we have developed using CRISPR/Cas9 is far quicker and more efficient than previous technologies, as well as being very consistent and accurate", said Prof. Munir Iqbal, head of the avian influenza group at Pirbright.

"HVT is already widely used in vaccines against Marek's disease and can be administered to eggs, enabling automated delivery and providing birds with protection from the day they hatch", Iqbal added.

Iqbal said that they incorporated an additional haemagglutinin (HA) gene, which is expressed by HVT when it replicates in host cells. This means that a single dose of vaccine induces immunity against both viruses, Iqbal explained. HA is an influenza protein that is key for virus entry into host cells and is, therefore, an important target of the host immune response to block infection.

"Improving how we make vaccines is critical for preventing avian influenza outbreaks. Our work could help reduce the spread of disease between birds and reduce the risk of infection for people who work closely with poultry", Iqbal said.