The present invention relates to protein antigens IcsP2 and SigA2 from Shigella that are common among numerous Shigella types and species and which can protect against shigellosis or other enteric infections when administered as vaccines. In addition, the present invention relates to antigens that are in common between Shigella species and enteroinvasive Escherichia coli (EIEC). The invention also relates to the use of antibodies raised against these antigens and of DNA probes for use in the diagnosis of Shigella and EIEC infections.