Background:
Brucellosis is endemic in India. Calfhood vaccination using live attenuated B. abortus S19 is practiced in India and many other countries for control of bovine brucellosis. However, S19 vaccine has major drawbacks in terms of its safety and interference with sero-diagnosis of clinical infection:
Technology Details:
To overcome the drawbacks, B. abortus S19 strain has been modified by deletion mutation. The developed strain has been named as Brucella abortus S19∆per (in short, S19∆per). Brucella abortus S19∆per vaccine technology describes an improved brucellosis vaccine for cattle and buffaloes. B. abortus S19∆per strain has been developed through deletion of perosamine synthetase gene (per gene) from conventional Brucella vaccine, S19. The perosamine synthetase gene is involved in Lipopolysaccharide (LPS) biosynthetic pathway. LPS is a major virulence factor in Brucella. Strong antibody response to Brucella infection is also mediated by LPS. LPS mediated antibody response to S19 vaccination interferes sero-diagnosis of clinical infection. Therefore, a modified S19 strain with truncated LPS would be safer and would elicit minimal anti-Brucella antibodies without affecting protective immune response. Being an intracellular pathogen, protective immunity against Brucella infection is primarily mediated by cellular immune response:
The proof of concept has been established in the newly developed Brucella abortus S19∆per strain.