title: Genetic variation of the prevailing porcine respiratory and reproductive syndrome viruses occurring on a pig farm upon vaccination.
abstract: Recurrence of porcine respiratory and reproductive syndrome (PRRS) was observed on a pig farm after introducing two PRRS live virus vaccines to combat preceding outbreaks. The phylogenetic analysis of the nucleotide sequence encoding the GP5 envelope glycoprotein and the nucleocapsid protein coding sequences (ORF5 and ORF7, respectively) showed a close genetic relationship between the new outbreak-related and one of the vaccine viruses, while the prevailing PRRS virus genetic variants disappeared from the farm. These findings, supported by the epidemiological data, indicate that the new variant PRRS viruses might originate from a vaccine virus and demonstrate the limited efficacy of modified live vaccines against heterologous PRRS virus strains.
authors.affiliation: Central Veterinary Institute, Institute of Debrecen, Debrecen, Hungary. kissi@oai.hu
authors.forename: I
authors.initials: I
authors.lastname: Kiss
authors.forename: L
authors.initials: L
authors.lastname: Sámi
authors.forename: S
authors.initials: S
authors.lastname: Kecskeméti
authors.forename: K
authors.initials: K
authors.lastname: Hanada
mesh_terms: D000822:Animal Husbandry; D000818:Animals; D004196:Disease Outbreaks / Q000517:prevention & control; D014644:Genetic Variation; D008969:Molecular Sequence Data; D019251:Nucleocapsid / Q000235:genetics; D010802:Phylogeny; D019318:Porcine Reproductive and Respiratory Syndrome / Q000453:epidemiology / Q000401:mortality / Q000517:prevention & control / Q000821:virology*; D019316:Porcine respiratory and reproductive syndrome virus / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D017422:Sequence Analysis, DNA; D013552:Swine; D014611:Vaccination / Q000662:veterinary*; D014759:Viral Envelope Proteins; D014764:Viral Proteins / Q000235:genetics; D014765:Viral Vaccines / Q000008:administration & dosage*
chemical_list: D014759:Viral Envelope Proteins; D014764:Viral Proteins; D014765:Viral Vaccines; C114789:glycoprotein 5, PRRSV