[ Objective ] The aim of the study was to construct associated DNA vaccine of PRRS （Porcine reproductive and respiratory syndrome） and PCV-2 （Porcine circovirus type 2） disease and study its immunogenicity. [ Method] In_ this study, the ORF5 gene of PRRSV isolated in Liaoning was cloned into plRES-neo expression vector, and the neo gene of plRES-neo expression vector was substituted by the ORF2 gene of the PCV-2 Mongolia strain to construct the recombinant expression vector. The expression in BHK cells was detected through Western blot and IFA. Then the ELISA antibody level and the number of spleen T lymphocytes were detected after Balb/c mice were immunized with this DNA vaccine. E Result] The recombinant plasmid plRES-ORF2-ORF5 was constructed successfully and could express the target proteins in BHK cells, as indicated by Western blot and IFA. There was no significant difference in ELISA antibody between plRES-ORF2-ORF5 immunized group and inactived vaccine immunized groups, while the number of spleen T lymphocytes induced by DNA vaccine was higher than that induced by inactived vaccine. [ Conclusion] The recombinant plasmid plRES-ORF2-ORF5 should induce good humoral immune response and cellular immune response in mice, providing the conditions for better prevention and control of PRRS and PCV-2 disease.
