• Vaccine Name: live attenuated Brucella abortus strain 19 rfbD deletion mutant vaccine
• Target Pathogen: Brucella spp.
• Target Disease: Brucellosis
• Vaccine Ontology ID: VO_0009441
• Type: Live attenuated vaccine
• Status: Research
• Host Species for Licensed Use: Cattle
• Host Species as Laboratory Animal Model: Mus musculus
• Antigen: rfbD deletion mutant
• Preparation: Live attenuated mutant strain S19ΔR exhibiting rough LPS phenotype confirmed by acriflavine dye-agglutination and LPS-SDS-PAGE analysis. (Lalsiamthara et al, 2020)
• Description: The study developed a rfbD gene deleted mutant of Brucella abortus strain 19 to overcome shortcomings of the parental S19 vaccine such as residual virulence, abortion induction, and sero-diagnostic interference. Efficacy: S19ΔR showed a protective index of 1.90 against virulent Brucella abortus challenge in mice. Immune response: The mutant induced significantly lower anti-Brucella humoral response compared to S19, with minimal induction of Brucella specific IgG1, IgG2a, IgG2b, and IgG3, resulting in no apparent reactivity to RBPT antigen, indicating DIVA compatibility. (Lalsiamthara et al, 2020)

Mouse Response

• Immune Response: The mutant induced significantly lower anti-Brucella humoral response compared to S19, with minimal induction of Brucella specific IgG1, IgG2a, IgG2b, and IgG3, resulting in no apparent reactivity to RBPT antigen, indicating DIVA compatibility. (Lalsiamthara et al, 2020)
• Challenge Protocol: Mouse model was used to assess virulence, splenic bacterial load, recovery time RT50, humoral immune response, and protection against virulent challenge. (Lalsiamthara et al, 2020)
• Efficacy: S19ΔR showed a protective index of 1.90 against virulent Brucella abortus challenge in mice. (Lalsiamthara et al, 2020)
• Description: Mouse model was used to assess virulence, splenic bacterial load, recovery time RT50, humoral immune response, and protection against virulent challenge. (Lalsiamthara et al, 2020)