• Vaccine Name: Orf Virus Vaccine PBK-asd
• Target Pathogen: Orf Virus
• Target Disease: Orf disease, Sore mouth (Ovine Ecthyma)
• Type: DNA vaccine
• Status: Research
• Host Species for Licensed Use: None
• Antigen: B2L protein and Kisspeptin-54 (neuropeptide) (Wassie et al., 2019)
• Preparation: The PVAX-asd plasmid was prepared by excising the kanamycin antibiotic resistance gene from PVAX1 plasmid and replaced by aspartate-β- semialdehyde dehydrogenase (ASD) gene. The orf virus isolate MT-05 B2L gene, GenBankTM accession number JN613809.1 was chemically synthesized and subcloned into PVAX-asd plasmid with NheI and BamHI restriction enzymes. The positive plasmid was identified by restriction digestion and confirmed by sequencing. Finally, the fusion plasmid labeled as PVAX-B2L-asd and stored in −20 °C. The recombinant B2L and kisspeptin-54 plasmid was constructed by subcloning the kisspeptin-54 into PVAX-B2L-asd plasmid. Briefly, the KISS1 gene and subcloned into PVAX-B2L-asd plasmid with BamHI and EcoRI restriction enzymes. The (G4S)3 linker was used to improve and maintain the folding, expression, and biological activity of the fusion protein. This recombinant plasmid labeled as PVAX-B2L-(G4S) 3-kisspeptin-54-asd (PBK-asd). (Wassie et al., 2019)
• Immunization Route: Intramuscular injection (i.m.)
• Description: Recombinant B2L and Kisspeptin-54 DNA vaccine induces immunity against Orf Virus in mice

Mouse Response

• Vaccination Protocol: The experiment was performed in the completely randomized design, and 36 rats were equally assigned into one of the following three groups: PBK-asd, PK-asd and PVAX-asd (control). Both the treatments and the control group rats were treated with (100 μg/dose) plasmid diluted in 1 ml saline. The injection was given through intramuscular route. All treatment rats were boosted twice at an interval of 3 weeks. (Wassie et al., 2019)
• Immune Response: he ELISA results showed that the anti-B2L antibody was significantly higher in the PBK-asd group than in the control group from the 4th week after the initial immunization until the end of the experiment (p < 0.05). This data suggesting that immunization of rats using recombinant B2L and kisspeptin-54 DNA vaccine could stimulate antibody production against orf virus envelope protein (B2L). Rats inoculated with PBK-asd vaccine up-regulated antigen-mediated splenocyte proliferation and significantly raised antigen-specific tumor necrosis factor-alpha (TNFα-), interferon-gamma (IFN-ϒ) and interleukin (IL-2) compared to the control group (p < 0.05). (Wassie et al., 2019)
• Efficacy: The capability of the vaccine to induce both humoral and cell-mediated immune response defines its efficacy. Our results showed that the recombinant PBK-asd vaccine induced a strong antigen-specific humoral ant-orf antibody after booster immunization. (Wassie et al., 2019)