Porcine Epidemic Diarrhea virus (PEDV) causes significant economic losses to the swine industry.Commercial vaccines are available,but are no longer effective on farms against the outbreak of a pandemic PEDV strain (SQ2014) in China.A recombinant swinepox virus vaccine (rSPV-Sa) expressing the truncated S protein from a pandemic PEDV strain (SQ2014) was constructed,and its immunogenicity and efficacy were also tested and characterized.Vaccination robustly increased the IgG titer specific for PEDV and induced neutralizing antibodies with a mean titer of 1∶16 at 42 days post-inoculation.The efficacy of the rSPV-Sa vaccine was tested in passive transfer models using homologous (SQ2014) and heterologous (CV777) challenges.In the homologous challenge,rSPV-Sa provided complete protection.None of the challenged animals showed clinical symptoms of PEDV infection and there was no mortality.The rSPV-Sa vaccine did not show protective efficacy in the heterologous challenge (100% mortality in challenged animals).Differences in the amino acid sequences of the two viruses were identified in the neutralizing epitope and might have contributed to the divergent clinical results.In summary,we are the first to describe the immunogenicity and protective efficacy of a recombinant SPV based PEDV vaccine expressing a truncated S protein in pigs.The results highly suggest that rSPV-Sa may be a potential candidate for an effective vaccine against the pandemic wild type PEDV strain SQ2014.The conclusions remain to be confirmed in large scale animal experiments.