This invention relates to a vaccine formulation against Shigellosis comprising the outer membrane vesicles (OMVs) of antigen from six serotypes of Shigella which includes- Shigella dysenteriae type 1 from sero-group A, Shigella flexneri 2a from sero group B, Shigella flexneri 3a and Shigella flexneri 6 from sero group B, Shigella boydii type 4 from sero group C and Shigella sonnei (phase -1) from sero group D.