• Vaccine Name: B. melitensis LPS-GBOMP
• Target Pathogen: Brucella spp.
• Target Disease: Brucellosis
• Vaccine Ontology ID: VO_0000312
• Type: Subunit vaccine
• Antigen: The antigens used in this vaccine were purified Brucella melitensis lipopolysaccharide (LPS) as a noncovalent complex with Neisseria meningitidis group B outer membrane protein (GBOMP) (Bhattacharjee et al., 2002).
• Preparation: To create the vaccine, the LPS was extracted from killed B. melitensis cells and purified. N. meningitidis group B strain 8047 bacteria were grown in a synthetic medium, and outer membrane protein (GBOMP) was extracted. The B. melitensis LPS-GBOMP noncovalent complex vaccine was prepared with purified B. melitensis LPS dissolved in 42 ml of TEEN buffer. This mixture was added to the LPS solution and kept at 5°C for 30 min. The detergent was removed, and buffer was exchanged with sterile 0.9% NaCl solution. The final product was filtered and the LPS content was determined (Bhattacharjee et al., 2002).
• Storage: The vaccines were stored at −20°C until use (Bhattacharjee et al., 2002).

Mouse Response

• Host Strain: BALB/c
• Vaccination Protocol: Each mouse was given an intramuscular injection of 0.3 mg of xylazine hydrochloride and 1.0 mg of ketamine hydrochloride in 50 μl of sterile saline prior to immunization. The mice were then immunized by administration of 25 μl of vaccine containing 10 μg of LPS slowly into the nostrils with a micropipette, with a second dose of vaccine was given 4 weeks after the initial dose (Bhattacharjee et al., 2002).
• Immune Response: Anti-B. melitensis LPS IgG titers were significantly increased two weeks after i.n. immunization with B. melitensis LPS-GBOMP vaccine. The pattern of IgG1 response closely resembled that of total IgG, but IgG2a and IgG2b responses were blunted compared to the IgG1 response,and the IgG3 response was also blunted compared to that of IgG1(Bhattacharjee et al., 2002).
• Challenge Protocol: Groups of immunized and control mice were challenged intranasally at various times with 10^4 CFU of B. melitensis 16 M suspended in 30 μl of phosphate-buffered saline. In one experiment, mice were challenged with 10^5 CFU of bacteria (Bhattacharjee et al., 2002).
• Efficacy: I.n. immunization with B. melitensis LPS-GBOMP subunit vaccine significantly protects mice against intranasal challenge with virulent B. melitensis. Vaccination reduces spleen and liver bacterial dissemination but has no effect on the course of lung infection (Bhattacharjee et al., 2002).