title: Inactivated genotype 1 Japanese encephalitis vaccine for swine.
abstract: Japanese encephalitis is a reproductive disorder caused by Japanese encephalitis virus (JEV) in swine. Recent genotype (G) shift phenomenon (G3 to G1) in the Asia-wide has posed a challenge for proper prevention by the current vaccine strain. Thus, new kinds of JEV G1 vaccines with enhanced immunogenicity have been required for pigs.
  
  
  
  Recombinant porcine granulocyte monocyte-colony stimulating factor (reporGM-CSF) protein was expressed in Spodoptera frugiperda (Sf-9) cells using baculovirus expression system. Two kinds of trials with inactivated JEV vaccines containing IMS1313 adjuvant (Seppic, France) were prepared with or without reporGM-CSF protein. Safety and immunogenicity of the pigs inoculated with the JEV vaccines via intramuscular route was evaluated for 28 days after inoculation.
  
  
  
  Mice, guinea pigs, and fattening pigs inoculated with the inactivated vaccine showed no signs for 14 and 21 days. Both hemagglutination inhibition and plaque reduction neutralizing antibody titers were significantly higher in pigs immunized with the vaccine containing reporGM-CSF protein after boosting. However, on the side of vaccine efficacy, most mice (87%) immunized with the inactivated JEV vaccine survived after virulent JEV challenge. Whereas the group with the vaccine containing reporGM-CSF protein showed lower protective effects than the vaccine alone for the biological activity of the GM-CSF depending on species specific.
  
  
  
  Our data indicate that animals inoculated with the JEV vaccines was safe and pigs inoculated with inactivated JEV vaccine containing reporGM-CSF protein showed higher humoral immune responses than that of inactivated JEV vaccine without reporGM-CSF protein.
authors.affiliation: Viral Disease Division, Animal and Plant Quarantine Agency, Ministry of Agriculture, Food and Rural Affairs (MAFRA), Anyang, Korea.
authors.forename: Dong-Kun
authors.identifier: http://orcid.org/0000-0001-5765-3043
authors.initials: DK
authors.lastname: Yang
authors.affiliation: Viral Disease Division, Animal and Plant Quarantine Agency, Ministry of Agriculture, Food and Rural Affairs (MAFRA), Anyang, Korea.
authors.forename: Jin-Ju
authors.identifier: http://orcid.org/0000-0002-5021-0941
authors.initials: JJ
authors.lastname: Nah
authors.affiliation: Viral Disease Division, Animal and Plant Quarantine Agency, Ministry of Agriculture, Food and Rural Affairs (MAFRA), Anyang, Korea.
authors.forename: Ha-Hyun
authors.identifier: http://orcid.org/0000-0001-6473-0035
authors.initials: HH
authors.lastname: Kim
authors.affiliation: Viral Disease Division, Animal and Plant Quarantine Agency, Ministry of Agriculture, Food and Rural Affairs (MAFRA), Anyang, Korea.
authors.forename: Jae-Young
authors.identifier: http://orcid.org/0000-0002-9554-9252
authors.initials: JY
authors.lastname: Song
keywords: GM-CSF; Inactivated vaccine; Japanese encephalitis virus; Swine