Immunogenic composition

An immunogenic composition comprising two or more polypeptides, wherein each polypeptide independently comprises a first region of contiguous amino acids, wherein:

• (a) the amino acid sequence of the first region has at least 80% sequence identity to an influenza A haemagglutinin head domain;
• and
• (b) the first region has one or more amino acid substitutions at positions which correspond to the following positions in SEQ ID NO:
• 9:
• position 83 is E
• position 85 is a negatively charged amino acid
• position 146 is T, N, I or A
• position 147 is a positively charged amino acid, I or is absent
• position 148 is G
• position 149 is V
• position 151 is A
• position 154 is S or P
• position 155 is H
• position 156 is a positively charged amino acid or A or G or N or E
• position 157 is a positively charged amino acid or A or G
• position 158 is a positively charged amino acid or A or S or N or C or E
• position 159 is K or A or S or N or C
• position 163 is a positively charged amino acid,
• wherein the amino acid sequences of the two or more polypeptides are different, and
• wherein the composition is capable of inducing antibodies in a subject against an influenza A virus, optionally together with one or more pharmaceutically-acceptable carriers, adjuvants, excipients or diluents.

A composition comprising a polypeptide, wherein the amino acid sequence of the polypeptide comprises a first region, wherein:

• (a) the amino acid sequence of the first region has at least 80% sequence identity to an influenza A subtype H1, H2, H3, H4, H5, H6, H7, H8, H9, H10, H11, H12, H13, H14, H15, H16, H17 or H18 haemagglutinin head domain, preferably an influenza A subtype H1, H5, H6, H9 or H11 haemagglutinin head domain;
• and
• (b) the first region has one or more amino acid substitutions at positions which correspond to the following positions in SEQ ID NO:
• 9:
• position 83 is E
• position 85 is a negatively charged amino acid
• position 146 is T, N, I or A
• position 147 is a positively charged amino acid, I or is absent
• position 148 is G
• position 149 is V
• position 151 is A
• position 154 is S or P
• position 155 is H
• position 156 is a positively charged amino acid or A or G or N or E
• position 157 is a positively charged amino acid or A or G
• position 158 is a positively charged amino acid or A or S or N or C or E
• position 159 is K or A or S or N or C
• position 163 is a positively charged amino acid.