PRRSV has become one of the most economically important diseases to the global pork industry.Current vaccination strategies only provide a limited protective efficacy.In this study,a DNA vaccine pVAXl(C)-α-γ-GP35 co-expressing GP3 and GP5 of PRRSV with interferon alpha/gamma was constructed and the immediate and long-lasting protection against highly pathogenic PRRSV (HP-PRRSV) challenge were examined in pigs.For immediate protection,the results showed that pVAXl(C)-α-γ-GP35 could provide partially protective efficacy,which was similar with the pVAX1(C)-α-γ (expressing interferon alpha/gamma).