• Vaccine Name: Porin and S-LPS Extracted from Virulent Brucella abortus 2308
• Target Pathogen: Brucella spp.
• Target Disease: Brucellosis
• Vaccine Ontology ID: VO_0000403
• Type: Subunit vaccine
• Antigen: The antigen for this vaccine is a complex of porin and smooth lipopolysaccharide (S-LPS) extracted from virulent Brucella abortus 2308 (Winter et al., 1988).
• Adjuvant:
  • Adjuvant name:
  • VO adjuvant ID: VO_0001250
  • Description: The porin-S-LPS was given without adjuvant or in several adjuvants: trehalose dimycolate and muramyl dipeptide; the pluronic polymer L-121 and muramyl dipeptide; or complexed with Quil A in immunostimulating complexes (Winter et al., 1988).
• Preparation: The S-LPS was produced from smooth strain 2308 by extraction in hot phenol followed by treatment with guanidinium thiocyanate. Inocula were prepared from a freshly thawed vial which was diluted in sterile phosphate buffered saline to yield an infecting dose of 5 x 10^4 bacteria per 0.1 ml. Each dose was mixed with its appropriate adjuvant (Winter et al., 1988).

Mouse Response

• Host Strain: BALB/c
• Vaccination Protocol: Five week-old female mice were used. The mice were vaccinated subcutaneously. Blood samples were taken on one or more occasions during the course of some experiments. Quantitative cultures for viable B. abortus were performed on spleens at 1 and 4 weeks postinfection. Each mouse was vaccinated with 30 micrograms of porin-S-LPS (Winter et al., 1988).
• Immune Response: Protective vaccines caused the formation of increased concentrations of circulating O-polysaccharide-specific antibodies, although there were individual exceptions to the quantitative associatiQn between O-polysaccharide-specific antibodies and protection. Antibodies specific for porin or R-LPS were found in negligible quantities in vaccinated mice (Winter et al., 1988).
• Challenge Protocol: B. abortus smooth strain 2308 of known virulence was used for challenge infections. In some experiments, vaccination or challenge was performed with vaccine strain 19. Animals were challenged 4 weeks postinfection with approximnately 5 x 10^4 CFU of live B. abortus cells (Winter et al., 1988).
• Efficacy: Vaccination with porin-S-LPS conferred significant protection against challenge infections with either B. abortus 2308 or 19 at both 1 and 4 weeks postinfection. The magnitude of protection was not significantly enhanced at either time period by the inclusion of TDM and MDP adjuvant in the vaccine. In contrast, vaccination with the same quantity of porin-R-LPS with or without adjuvant provided no significant protection against either challenge strain (Winter et al., 1988).