Antibodies against h5n1 strains of influenza a virus

Abstract

Provided are human antibodies that can neutralize a H5N1 strain of influenza A virus. Also provided are antibodies that can neutralize a strain of influenza A virus in clade 2 of the H5 subtype, that can neutralize a H5N1 strain of influenza A virus and have a lambda light chain, and that are IgG antibodies (but not with a IgG1 heavy chain) that can neutralize a H5N1 strain of influenza A virus.

1 . An isolated antibody, or an antigen binding fragment thereof, that neutralizes a H5N1 strain of influenza A virus comprising the heavy chain CDR1, CDR2 and CDR3 and the light chain CDR1, CDR2, and CDR3 sequences as set forth in SEQ ID NOs: 17-22, 23-28, 29-34, 35-40, 45-50, 55-60, 65-70, 75-80, 85-90, 95-100, or 105-110, respectively, wherein the concentration of antibody or antigen binding fragment required for 50% neutralisation of H5N1 in clade 1 is 10 μg/ml or lower. 
     
     
         2 . The antibody of  claim 1 , or an antigen binding fragment thereof, wherein the concentration of antibody or fragment required for 50% neutralisation of H5N1 in clade 1 is 1 μg/ml or lower. 
     
     
         3 . The antibody of  claim 1 , or an antigen binding fragment thereof, wherein the concentration of antibody or fragment required for 50% neutralisation of H5N1 in clade 1 is 100 ng/ml or lower. 
     
     
         4 . The antibody of  claim 1 , or an antigen binding fragment thereof, wherein the antibody or fragment can neutralize a H5N1 strain of influenza A virus in clade 1 and a H5N1 strain of influenza A virus in clade 2. 
     
     
         5 . The antibody of  claim 4 , or an antigen binding fragment thereof, wherein the antibody or fragment can neutralise 100 TCID 50  of both a H5N1 strain of influenza A virus in clade 1 and a H5N1 strain of influenza A virus in clade 2 at a concentration of 1 μg/ml or lower. 
     
     
         6 . A pharmaceutical composition comprising two antibodies of  claim 1 , or antigen binding fragments thereof, wherein the antibodies can, between them, neutralize a clade 1 and a clade 2 H5N1 strain of influenza A virus. 
     
     
         7 . The pharmaceutical composition of  claim 6 , wherein said antibodies bind to different epitopes on the same H5 hemagglutinin.