title: An oral Aujeszky's disease vaccine (YS-400) induces neutralizing antibody in pigs.
abstract: OBJECTIVE
  Aujeszky's disease (AD) is an economically important disease affecting both wild and domestic pigs of the species Sus scrofa. A previous study yielded serological evidence of AD in Korean wild boars, which could spread AD to other animals. A new Aujeszky's disease virus (ADV) bait vaccine is required to prevent AD outbreaks in swine. In the present study, we investigated the safety and immunogenicity of a gE-deleted marker vaccine, strain YS-400, in young domestic pigs.
  
  
  METHODS
  The YS-400 strain was propagated in Vero cells, and the trial ADV bait vaccine (a vaccine blister in a matrix including an attractant) was prepared. Pigs were orally immunized with the vaccine (2 mL, 10(7.5) TCID50/mL) delivered using a syringe or in the bait vaccine. The animals were observed for 9 weeks after vaccination, and immunogenicity was assessed using a virus neutralization (VN) test and enzyme linked immunosorbent assay.
  
  
  RESULTS
  The YS-400 strain was non-pathogenic to pigs when given orally and induced high VN titers (1:32-1:128) 6 weeks post-administration. Of the pigs given the ADV bait vaccine twice or three times, 40% were seropositive by 2 weeks, and 100% were seropositive by 7 weeks after the first dose. Pigs that consumed the AD bait vaccine three times developed VN titers that were slightly higher than those of pigs given the vaccine twice.
  
  
  CONCLUSIONS
  Domestic pigs given the trial ADV bait vaccine exhibited no adverse effects and developed high VN titers against ADV, indicating that the YS-400 strain is safe and can prevent ADV infection in domestic pigs.
authors.affiliation: Viral Disease Division, Animal and Plant Quarantine Agency, MAFRA, Gimcheon, Korea.
authors.forename: Dong-Kun
authors.identifier: 0000-0001-5765-3043
authors.initials: DK
authors.lastname: Yang
authors.affiliation: Viral Disease Division, Animal and Plant Quarantine Agency, MAFRA, Gimcheon, Korea.
authors.forename: Ha-Hyun
authors.identifier: 0000-0001-6473-0035
authors.initials: HH
authors.lastname: Kim
authors.affiliation: Viral Disease Division, Animal and Plant Quarantine Agency, MAFRA, Gimcheon, Korea.
authors.forename: Sung-Suk
authors.identifier: 0000-0001-5124-9736
authors.initials: SS
authors.lastname: Choi
authors.affiliation: Viral Disease Division, Animal and Plant Quarantine Agency, MAFRA, Gimcheon, Korea.
authors.forename: Bang-Hun
authors.identifier: 0000-0002-3429-3425
authors.initials: BH
authors.lastname: Hyun
authors.affiliation: Viral Disease Division, Animal and Plant Quarantine Agency, MAFRA, Gimcheon, Korea.
authors.forename: Jae-Young
authors.identifier: 0000-0002-9554-9252
authors.initials: JY
authors.lastname: Song
keywords: Aujeszky's disease virus; Immunity; Oral vaccine