Patent ID: 8071084

Claim:
A method of protecting a susceptible host against an infection of Shigella sonnei ( S. sonnei ) comprising administering to said host an amount of an immunoprotective composition sufficient to invoke an immunoprotective response in the host, wherein the composition comprises an attenuated bacteria expressing an antigen comprising the S. sonnei form I O-polysaccharide, wherein said attenuated bacteria comprises an expression cassette comprising the genes wbgT, wbgU, wzx, wzy, wbgV, wbgW, wbgX, wbgY, and wbgZ isolated from the S. sonnei rfb/rfc gene cluster or Plesiomonas shigelloides ( P. shigelloides ) O17 gene cluster operably linked to transcriptional promoter and termination signals, and wherein the expression cassette does not include at least one of the following genes: IS1, wzz, IS630, aqpZ, IS629, IS91, and IS911.