• Vaccine Name: Classical swine fever virus vaccine VAC-E0
• Target Pathogen: Classical swine fever virus
• Target Disease: Classical swine fever, hog cholera
• Vaccine Ontology ID: VO_0011427
• Type: Recombinant vector vaccine
• Status: Research
• Antigen: Classical swine fever virus envelope glycoprotein E0
• E0 gene engineering:
  • Type: Recombinant vector construction
  • Description: A 0.7-kbp fragment (corresponding to nucleotides 1114 to 1838 of CSFV Alfort Tu¨bingen which encompassed the coding sequence for all but 5 amino acids (aa) of CSFV E0 was isolated from plasmid pHCK11 by digestion with BglI and BanI. The missing codons were substituted for with synthetic adaptor oligonucleotides. The 59 adaptor BBA (59GATCCACCAT GGGGGCCCTGT39) linked the BglI site of the 0.7-kbp fragment to the BamHI site of pGS62 and contained a sequence according to Kozak’s rules. Besides the initial methionine, BBA coded for 3 aa: glycine (not found in the CSFV sequence) and alanine and leucine (corresponding to CSFV aa 250 and 251). The 39 adaptor BEA (59GTGCCTATGCCTGAGTTA39) connected the BanI site of the 0.7-kbp fragment to the EcoRI site of pGS62 and encoded amino acids corresponding to glycine 491 to alanine 494 of CSFV as well as a stop codon. After ligation with adaptors BBA and BEA, the 0.7-kbp fragment was introduced into recombination vector pGS62 to derive plasmid pGS62-E0 (König et al., 1995). To generate a VVR vaccine, CVI cells were infected with vaccinia virus strain WR (VAC-WR) at a multiplicity of infection (MOI) of 0.05 and after 1 h were transfected with the respective recombination plasmids by using a mammalian transfection kit. After 48 h of incubation, virus progeny was harvested by repeated freezing and thawing. Selection for a thymidine kinase-negative phenotype on human 143tk2 cells was carried out with medium containing 1% agarose and 100 mg of bromodeoxyuridine per ml. VVR were isolated from thymidine kinase negative virus plaques and were plaque purified twice (König et al., 1995).
  • Detailed Gene Information: Click Here.
• Immunization Route: Intradermal injection (i.d.)

Pig Response

• Vaccination Protocol: Pigs were vaccinated with a single dose of VVR (VAC-E0 or VAC-E2) or control strain VAC-WR by three different routes simultaneously (intradermally, intraperitoneally, and intravenously). A total of 5 x 10^7 PFU of VVR was given by each route. Clinical reactions after vaccination were monitored by daily examination (König et al., 1995).
• Challenge Protocol: The pigs were challenged intranasally 5 weeks after immunization with 2 x 10^7 50% tissue culture infective doses of CSFV Alfort Tu¨bingen. Clinical symptoms were monitored daily. Blood samples were taken at days 5 and 12 postinfection (p.i.) and at the slaughter of the animals (days 12 to 27 p.i.) (König et al., 1995).
• Efficacy: Swine vaccinated with VVR expressing E0 and/or E2 resisted a lethal challenge infection with CSFV. Glycoprotein E0 represents a second determinant for the induction of protective immunity against classical swine fever (König et al., 1995).