Development of DNA vaccines against porcine circovirus type 2 and their immune efficacy in mice

Eukaryotic expression recombinant plasmids pcDNA3-ORF2,pcDNA3-V1,pcDNA3-V2,pcDNA3-V3 and pcDNA3-V1-V2 were constructed by using pcDNA3,PCV2 ORF2,and the variant regions of PCV2 ORF2 in order to develop DNA vaccines against porcine circovirus type 2(PCV2).After quantities of the 5 recombinant plasmids were produced and purified,five groups of 5-week-old female mice were immunized with one of the 5 plasmids,respectively,and levels of the antibody against PCV2 in sera from the immunized mice were detected by ELISA.The results showed that antibody levels of mice immunized with the 5 plasmids were different,and the plasmid pcDNA3-V1-V2 induced the highest antibody level which lasted the longest among the 5 plasmids.