has role protective antigen role protective antigen Salmonella spp. protein TviB The viaB (tviB) gene coding for the Vi antigen of Salmonella typhi Ty2 was subcloned into expression vector pYA248. The recombinant plasmid was termed SMM202 and transformed into Salmonella typhimurium 4072, an attenuated crp mutant. Immunization of mice with Vi4072 afforded complete protection against fatal infection with virulent S. typhi Ty2 [PubMed: 1612747]. protein Oliver He Allen Xiang Protegen ID: 729; NCBI Gene GI: 1067316; NCBI Protein GI: 29144603; NCBI Protein Accession: NP_807945; NCBITaxon: 209261