Classical Swine Fever (CSF) is a highly contagious hemorrhagic disease in swine causing substantial economic losses to the swine industry worldwide. Currently available vaccines include live attenuated virus vaccines and subunit vaccines. Live attenuated virus vaccines can be efficient at triggering rapid animal immune response and protecting swine populations when combined with culling of infected pigs. However, such vaccines do not allow the Differentiation of Infected from Vaccinated Animals (DIVA) and are therefore not desired vaccine candidates. More importantly, live attenuated virus vaccines are not approved in the U.S. Therefore, the development of DIVA compatible and efficacious vaccination solutions remains a top priority to prevent the economic impacts of a CSF outbreak including supply reductions, export restrictions and food security.
This program will create a biobetter vaccine by enhancing the quality and efficacy of a CSF subunit vaccine by improving thermal stability of the antigen, and improving antigen presentation and release. These advancements at the molecular level are designed to promote long-lasting protection after a single injection in the long term and offer the capability to differentiate infected from vaccinated animals. The CSF vaccine candidates will be produced in the plant Nicotiana benthamiana to leverage the scalability and affordability of the plant transient expression technology used by iBio biotherapeutics.
Outcomes and impacts
Previously developed CSF virus (CSFv) subunit vaccines suffer from thermal instability and poor long-lasting protection. This project aims to optimize the molecular design, production, and stability of a novel CSF subunit vaccine using iBio’s low-cost, rapid-to-launch plant expression platform, and evaluation and quantification of the swine immune response to plant-made CSFv antigen candidates. The development of a plant-made self-adjuvanted CSFv subunit vaccine will provide a more stable and protective option and potentially reduce the manufacturing cost of the final product. If higher thermal stability is demonstrated for plant-made CSFv candidate vaccines, such vaccines will have the potential to ultimately reduce or eliminate the burden of maintaining a cold chain in the field. Furthermore, the development of reliable tests to distinguish between infected animals and animals vaccinated with the plant-made CSFv antigens will follow. Assuming the approach is successful for the CSFv vaccine, this technology can be applied to other DIVA compatible subunit vaccine development programs for rapid deployment.