• A plant?produced immunoenhanced pig vaccine against PRRS

Scientific Summary

Porcine reproductive respiratory syndrome virus (PRRSV) causes the most important infectious disease in pigs in Denmark and globally. It has high impact on animal welfare and agricultural economics, and the extensive use of antibiotics to control PRRSV-associated respiratory problems may endanger public health. Thus, control of PRRSV is top priority in all pig producing countries.

Contrary to most other virus infections PRRSV persists in the blood for weeks after antibodies are formed due to dominant decoy antigens masking the subdominant epitopes that provide immunity at later stages. PRRSV is extremely difficult to control as existing vaccines are not effective in preventing infection or excretion of virus. Consensus is that PRRSV can only be controlled by vaccines that are safe, efficacious and rapidly adaptable to prevalent strains.

State-of-the-art vaccine research has identified non-infectious subunit vaccines such as virus-like-particles (VLPs) to be the most efficient entities developed to date, triggering both humoral and cellular immune responses.

We propose to alter  immunosuppressive motifs in the major target for neutralizing antibodies of PRRSV (GP5) and to produce VLPs presenting the modified GP5 in plants to gain advantages in terms of safety, speed, cost, and efficacy. This poses scientific challenges such as

  • i) membrane presentation of an animal virus protein in plants
  • ii) association of GP5 with VLPs formed by a cytosol-delivered matrix protein
  • iii) verification and modification of immunosuppressive domains in GP5 and
  • iv) efficient production. VLPs will be characterized and vaccine efficacy tested in pigs.

If successful, the project will provide industrial scale ready proof-of-concept for a novel PRRSvaccine and establish a platform technology for future vaccines against e.g. SARS or HIV.