A hypervesiculating Shigella bacterium that expresses no more than 4 proteins between TolA, TolB, TolQ, TolR and Pal and that does not express a native Shigella lipopolysaccharide.Una bacteria Shigella hipervesiculante que expresa no más de 4 proteínas entre TolA, TolB, TolQ, TolR y Pal y que no expresa un lipopolisacárido de Shigella nativo.