 In reality, the multiple isolates of paramyxoviruses in pigs, using modern nucleic acid sequencing methods, have never been identified as SeV.All viruses in the "Paramyxoviridae" family are antigenically stable; therefore the family representatives that are close relatives and belong to the same genus, most likely, share common antigenic determinants.Thus, porcine parainfluenza 1, which has high sequence homology with SeV and also belongs to the same as SeV Respirovirus genus, probably, has cross-reactive antibodies with SeV.