has function has role immunizes recipient immunizes against pathogen Shigella flexneri Homo sapiens preventive vaccine function prophylactic vaccine vaccine in clinical trial role CVD 1208 vaccine CVD 1208 is derived from wild type Shigella flexneri 2a strain 2457T and has defined deletions in four genes: (1) the guaBA chromosomal operon that encodes two enzymes (inositol 5'-monophosphate dehydrogenase and guanosine 5'synthase) essential for de novo purine biosynthesis; (2) set, a locus in a chromosomal pathogenicity island that encodes Shigella enterotoxin (ShET); (3) Pic, an autotransporter mucinase encoded on the opposite strand from set; and (4) sen, an invasiveness plasmid gene encoding ShET. Oliver He PMID:15499528 VIOLIN: https://violinet.org/vaxquery/vaccine_detail.php?c_vaccine_id=441 441 vaccine CVD 1208 Shigella flexneri vaccine live attenuated bacterial vaccine live attenuated vaccine role