ArterivirusArterivirus InfectionsArteritis Virus, EquinePorcine respiratory and reproductive syndrome virusNidoviralesArteriviridaeLactate dehydrogenase-elevating virusPorcine Reproductive and Respiratory SyndromeRNA ReplicaseAntigens, CD8Antigens, CD3CD40 LigandRNA, ViralAntigens, CD40Antigens, CD44Antigens, CD34Antigens, CD28CD4-CD8 RatioOpen Reading FramesViral Nonstructural ProteinsVirus ReplicationGenome, ViralHorsesCricetinaeMolecular Sequence DataAntigens, CD14Antigens, CD38Cell LineCD4-Positive T-LymphocytesAntigens, CD1Antigens, CD80Antigens, CD2