title: Pseudorabies virus variant in Bartha-K61-vaccinated pigs, China, 2012.
abstract: The widely used pseudorabies virus (PRV) Bartha-K61 vaccine has played a key role in the eradication of PRV. Since late 2011, however, a disease characterized by neurologic symptoms and a high number of deaths among newborn piglets has occurred among Bartha-K61-vaccinated pigs on many farms in China. Clinical samples from pigs on 15 farms in 6 provinces were examined. The PRV gE gene was detectable by PCR in all samples, and sequence analysis of the gE gene showed that all isolates belonged to a relatively independent cluster and contained 2 amino acid insertions. A PRV (named HeN1) was isolated and caused transitional fever in pigs. In protection assays, Bartha-K61 vaccine provided 100% protection against lethal challenge with SC (a classical PRV) but only 50% protection against 4 challenges with strain HeN1. The findings suggest that Bartha-K61 vaccine does not provide effective protection against PRV HeN1 infection.
authors.forename: Tong-Qing
authors.initials: TQ
authors.lastname: An
authors.forename: Jin-Mei
authors.initials: JM
authors.lastname: Peng
authors.forename: Zhi-Jun
authors.initials: ZJ
authors.lastname: Tian
authors.forename: Hong-Yuan
authors.initials: HY
authors.lastname: Zhao
authors.forename: Na
authors.initials: N
authors.lastname: Li
authors.forename: Yi-Min
authors.initials: YM
authors.lastname: Liu
authors.forename: Jia-Zeng
authors.initials: JZ
authors.lastname: Chen
authors.forename: Chao-Liang
authors.initials: CL
authors.lastname: Leng
authors.forename: Yan
authors.initials: Y
authors.lastname: Sun
authors.forename: Dan
authors.initials: D
authors.lastname: Chang
authors.forename: Guang-Zhi
authors.initials: GZ
authors.lastname: Tong
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000276:immunology; D002681:China; D011558:Herpesvirus 1, Suid / Q000235:genetics* / Q000276:immunology* / Q000302:isolation & purification; D009500:Neutralization Tests; D010802:Phylogeny; D011557:Pseudorabies / Q000276:immunology* / Q000517:prevention & control*; D022421:Pseudorabies Vaccines / Q000276:immunology*; D013552:Swine; D013553:Swine Diseases; D014611:Vaccination; D014759:Viral Envelope Proteins / Q000235:genetics
chemical_list: D000914:Antibodies, Viral; D022421:Pseudorabies Vaccines; D014759:Viral Envelope Proteins
keywords: Bartha-K61 vaccine strain; China; immune evasion; pigs; pseudorabies virus; virulent; virus variant; viruses