The Pirbright Institute will undertake two projects with ECO Animal Health Group plc (ECO) to develop vaccine candidates for porcine respiratory and reproductive syndrome virus (PRRSV). The first project is a tripartite collaboration between The Pirbright Institute, The Vaccine Group (TVG) and ECO whilst the second project is a joint collaboration between Pirbright and ECO.

Collectively, the two PRRSV species (type-1 and type-2) are responsible for one of the most economically damaging diseases to the global pig industry, costing European pig farmers an estimated €1.5 billion a year and those in the US approximately $600 million.

In the first 18-month development project, supported and funded by ECO, Pirbright will test two vaccine candidates that use TVG’s vaccine technology to assess their effectiveness at tackling PRRSV in pigs.

The vaccines are created by using TVG technology to insert non-infectious conserved PRRSV genes supplied by Pirbright into a benign herpesvirus, which then stimulates the immune system when delivered into animals. Vaccines that use herpesviruses as their base have been shown to provoke particularly strong reactions from T cells, which are a vital part of the antiviral response.

Professor Simon Graham, Group Leader of PRRS Immunology at The Pirbright Institute said: “This is an exciting project that takes a novel approach to addressing the urgent requirement for improved vaccines to combat the global spread of PRRSV.”

TVG Founder and Chief Scientific Officer, Associate Professor Dr Michael Jarvis said: “This is an exciting opportunity that brings together critical basic science and translational expertise towards addressing this major infectious disease in pigs. As PRRSV is a member of the Nidovirus group of viruses, a group that also contains SARS-CoV-2, what we learn from development of a PRRSV vaccine may also help inform our development of a vaccine against SARS-CoV-2.”

Dr Hafid Benchaoui, Head, Global R&D, ECO Animal Health Group said: “ECO Animal Health recognises the significant, ongoing challenge that PRRSV poses for pig producers all over the world. This collaboration with The Pirbright Institute and The Vaccine Group leverages the deep scientific expertise of Pirbright and The Vaccine Group’s novel herpesvirus vector technology in an exciting new approach to PRRSV vaccination.”

The second ECO funded project will see Pirbright develop a significantly improved killed vaccine over 18 months. The team will generate modified PRRSV strains and then inactivate them to create vaccine candidates. The strain modifications aim to prevent inappropriate antibody responses and enhance those that are thought to provide immunity against multiple strains of PRRSV.

This killed vaccine would offer an attractive alternative to the current generation of live vaccines, which are only partially effective against different strains and suffer from safety constraints owing to the potential for the live vaccine virus to revert back to an infectious form.

Professor Simon Graham said: “Creating a killed vaccine that can prevent the spread of multiple strains would provide flexibility in tackling outbreaks as well as an improved safety profile, both vital for effective control.”

Dr Hafid Benchaoui, Head, Global R&D, ECO Animal Health Group said: “This novel concept will provide better protection of pigs against PRRSV than current vaccines and will be safer by eliminating the significant risk of recombination in the field.”