• Vaccine Name: B. melitensis with deleted bp26 (CGV26)
• Target Pathogen: Brucella spp.
• Target Disease: Brucellosis
• Vaccine Ontology ID: VO_0000338
• Type: Live, attenuated vaccine
• Antigen: The antigen for this vaccine is Brucella melitensis containing a deletion of the bp26 gene, a strain called CGV26 (Guilloteau et al., 2006).
• RL3382 gene engineering:
  • Type: Recombinant protein preparation
  • Description: The CGV26 and CGV2631 strains were engineered with Brucella melitensis Rev.1 mutant strains containing deletions in the bp26 gene or both bp26 and omp31 genes (Guilloteau et al., 2006).
  • Detailed Gene Information: Click Here.
• Preparation: Mutants were kept freeze-dried. Bacteria were rehydrated in sterile buffered saline solution, seeded on Trypticase Soy Agar, supplemented with yeast extract and incubated at 37 °C. Fresh bacterial suspensions were harvested in BSS from 24 h cultures and spectrophotometrically adjusted. Each suspension used was always checked for purity and dissociation and the exact doses were assembled (Guilloteau et al., 2006).
• Virulence: The virulence of the CGV26 mutant was similar to that of the parental Rev.1 strain (Guilloteau et al., 2006).

Sheep Response

• Host Strain: Préalpes
• Vaccination Protocol: 42 Brucella-free Préalpes females of 3–4 months of age were randomly allotted into seven groups of six animals. Six groups were inoculated either by CJ or SC route with 1 × 10^9 cfu of CGV26 mutant or the Rev.1 vaccine as a vaccinated control group. The vaccine suspension was administered conjunctivally with a calibrated dropper by depositing 33 μl on the surface of the right eye or subcutaneously with a needle by injecting 1 ml just behind the left elbow joint. One group remained as a separate uninfected control group. Swabs were taken from the conjunctiva and nostrils in groups inoculated by CJ route for bacteriological analyses. At regular intervals after inoculation, blood samples were collected for analysis of the immune response induced (Guilloteau et al., 2006).
• Persistence: The local persistence of the CGV26 mutant was not statistically different from the Rev.1 strain (Guilloteau et al., 2006).
• Immune Response: The results together showed that the CGV26 mutant was able to induce both specific antibody response and systemic lymphoproliferation in sheep. Specific systemic antibody response to S-LPS of Brucella was induced after inoculation of the mutant and the Rev.1 strain. The intensity of this response was much higher and earlier after SC vaccination (1 week) than that after CJ vaccination (second week) (Guilloteau et al., 2006).
• Efficacy: This mutant induced significant specific antibody and cell-mediated immunity in sheep (Guilloteau et al., 2006).