A suicidal DNA vaccine co-expressing two major membrane-associated proteins of porcine reproductive and respiratory syndrome virus antigens induce protective responses.

We constructed a suicidal DNA vaccine pSFV-ORF5m/ORF6 co-expressing GP5m (a modified GP5) and M proteins of porcine reproductive and respiratory syndrome virus (PRRSV). In mice immunization, specific immune responses were elicited by the suicidal DNA vaccine pSFV-ORF5m/ORF6. The immunogenicity and protective efficiency was then evaluated in piglets immunized with pSFV-ORF5m/ORF6 before virus challenge: PRRSV-specific neutralizing antibodies and lymphocyte proliferative responses were developed. Post-PRRSV challenge, these immune responses were further boosted and partial protection was obtained.