[Generation and characterization of recombinant classical swine fever virus C-strain expressing the cap protein of porcine circovirus type 2].

Classical swine fever (CSF), caused by classical swine fever virus (CSFV), is a devastating viral disease in swine, leading to significant economic losses to the pig husbandry. C-strain is one of the best modified live vaccines against CSF. The vaccine is highly safe and efficacious and can provide rapid and complete protection against essentially all genotypes of CSFV. Co-infections of pigs with CSFV and porcine circovirus type 2 (PCV2) occur frequently in the field, making it difficult to control the associated diseases. Here, a recombinant C-strain rHCLV-Cap expressing the Cap protein of PCV2 was constructed and evaluated in vitro and in vivo. The recombinant had comparable phenotypes to C-strain in cell cultures and rabbits. At ten days post-immunization, anti-E2, but not anti-Cap, antibodies were detected in the rabbits inoculated with the recombinant virus. Our study warrants further work to construct C-strain-based bivalent vaccines.