Production and immunogenicity of a deoxyribonucleic acid Alphavirus vaccine expressing classical swine fever virus E2-Erns protein and porcine Circovirus Cap-Rep protein

Abstract

Classical swine fever virus (CSFV) and porcine Circovirus type 2 (PCV2) are economically pivotal infectious disease viruses of swine. Alphaviral RNA replicon plasmids have been used as an important vector for constructing nucleic acid vaccines. Here, we aimed to construct a recombinant alphaviral plasmid vaccine pSCA1-E2-Erns-Cap-Rep for the prevention and control of CSFV and PCV2. Our results showed that the recombinant alphaviral plasmid vaccine pSCA1-E2-Erns-Cap-Rep was successfully constructed. The vaccine encoding E2 and Erns of CSFV, Cap, and Rep of PCV2 can induce E2, Erns, Cap, and Rep protein expression. ELISA analysis showed that mice-immunized pSCA1-E2-Erns-Cap-Rep plasmid vaccine produced higher anti–CSFV- and anti–PCV2-specific antibodies with dose- and time-dependent manners. Furthermore, neutralizing assays were measured using IF and ELISA methods. The results showed the production of neutralizing antibodies could neutralize CSFV (up to 210.13) and PCV2 (28.6) effectively, which exhibited the immune efficacy of the pSCA1-E2-Erns-Cap-Rep plasmid vaccine. Taken together, this pSCA1-E2-Erns-Cp-Rep plasmid vaccine could be considered a novel candidate vaccine against CSFV and PCV2.

A Comprehensive Review of Our Understanding and Challenges of Viral Vaccines against Swine Pathogens

“…A DNA vaccine encoding the E2 protein gene was used against CSFV and shown to confer total protection following virulent challenge [ 121 ]. Recently, a novel bivalent vaccine containing the recombinant alphaviral plasmid encoding the E2 and Erns proteins of CSFV and Rep as well as the Cap of PCV2 showed promising results in mice [ 122 ]. The mosaic vaccines have been developed using the DNA vaccine strategy for viruses with different strains with limited cross-protection.…”