Several PEDV vaccine candidates have been successfully cloned using the transformation-associated recombination (TAR) cloning in yeast. The clones have been sequence verified by NGS. Several clones have also been equipped with a reporter gene (green fluorescent protein gene) to monitor and facilitate virus replication and production. The obtained viruses will be assessed concerning their attenuation in vivo and subsequently the efficacy to protect from wild-type virus infection will be assessed.
We expect that several of the produced vaccine candidates will show sufficient attenuation to move forward to assess the vaccine efficacy. The reverse genetic system to produce the vaccine candidates is versatile and can be applied to modify and adapt the vaccine. This will allow to update the vaccine in case novel strains may emerge. It is also possible to extend this approach to other coronaviruses that cause severe disease in pigs.