Patent ID: 8790635

Claim:
A vaccine comprising: Salmonella typhi Ty21a comprising core-linked Shigella dysenteriae serotype 1 O-specific polysaccharide (O-Ps) and DNA encoding O antigen biosynthesis, said DNA selected from the group consisting of: DNA encoding variants of Shigella dysenteriae serotype 1 biosynthesis polypeptides encoded by any one of SEQ ID NOs: 1 and 2, wherein the variants comprise 0 antigen biosynthesis polypeptide analogs, wherein one or more of the specified amino acids is deleted or replaced, or wherein one or more non-specified amino acids are added without loss of biosynthesis of Shigella dysenteriae serotype 1 O antigen or protective immunological activity of the O antigen biosynthesis gene product; in combination with a physiologically acceptable carrier.