Brucella abortus S19 Delta Pe28 vaccine

The **Brucella abortus S19 Delta Pe28 vaccine** is a live attenuated bacterial vaccine derived from the standard Brucella abortus strain S19, with a targeted deletion in the pe28 gene to enhance safety and distinguishability from wild-type strains. As a modified version of the S19 vaccine, it induces protective immunity against bovine brucellosis by eliciting humoral and cellular responses specific to Brucella antigens while minimizing persistence and virulence-associated effects of the parental strain. Primarily indicated for immunization of cattle to prevent abortion and infection caused by B. abortus, it leverages the attenuated phenotype of S19—due to defects in erythritol metabolism and other virulence factors—with the pe28 deletion likely further reducing regulatory gene-mediated persistence.