Immunogenic compositions

Abstract

This invention relates to immunogenic compositions, particularly vaccine compositions, for use in providing protection against illness caused by bacterial infection with Shigella strains.

1 . An immunogenic composition comprising (a) purified  Shigella sonnei  GMMA, (b) purified  Shigella flexneri  GMMA and (c) an adjuvant, wherein the GMMA comprise modified lipid A. 
     
     
         2 . The immunogenic composition of  claim 1  wherein the modified lipid A is a penta-acylated lipid A. 
     
     
         3 . The immunogenic composition of  claim 1  wherein the  Shigella flexneri  GMMA are purified from at least one strain selected from the group consisting of 2a, 3a and 6. 
     
     
         4 . The immunogenic composition of  claim 3  wherein the immunogenic composition comprises  Shigella flexneri  GMMA purified from each of strains 2a, 3a and 6. 
     
     
         5 . The immunogenic composition of  claim 4  wherein the GMMA are purified from (a)  Shigella sonnei  ΔtolR, ΔhtrB, virG::nadAB, (b)  Shigella flexneri  2a ΔtolR, ΔmsbB or  Shigella flexneri  2a ΔtolR, ΔhtrB (c)  Shigella flexneri  3a ΔtolR, ΔmsbB or  Shigella flexneri  3a ΔtolR, ΔhtrB and (d)  Shigella flexneri  6 ΔtolR, ΔmsbB or  Shigella flexneri  6 ΔtolR, ΔhtrB. 
     
     
         6 . The immunogenic composition of  claim 1  wherein the  S. sonnei  strain is  S. sonnei  53G. 
     
     
         7 . The immunogenic composition of  claim 1  wherein the  S. flexneri  strain(s) are selected from the group consisting of  S. flexneri  2457T (2a),  S. flexneri  6885 (3a) and  S. flexneri  10.8537 (6). 
     
     
         8 . The immunogenic composition of  claim 3  wherein the composition comprises at least one further  Shigella flexneri  strain selected from the group consisting of 1b and 2b. 
     
     
         9 . The immunogenic composition of  claim 8  wherein the further  Shigella flexneri  strain(s) are selected from the group consisting of  S. flexneri  STANSFIELD (serotype 1b) and  S. flexneri  69/50 (serotype 2b). 
     
     
         10 . The immunogenic composition of  claim 4  wherein at least two of the four types of GMMA are present in a ratio of from 1:4 to 4:1. 
     
     
         11 . The immunogenic composition of  claim 1  wherein the adjuvant is aluminium hydroxide. 
     
     
         12 . The immunogenic composition of  claim 1  wherein at least 75% of the GMMA have a diameter within the range of 25 nm to 40 nm. 
     
     
         13 . The immunogenic composition of  claim 1  which comprises at least one pharmaceutical carrier(s) and/or excipients. 
     
     
         14 . The immunogenic composition of  claim 13  which is a pharmaceutical or vaccine composition. 
     
     
         15 . A method of prevention or treatment of infection by  Shigella  comprising the step of providing a suitable amount of the immunogenic composition of  claim 14 . 
     
     
         16 . A method for immunising a patient against infection by  Shigella  comprising the step of administering to the patient an immunogenic composition of the first aspect of the invention.