Methods of boosting immune responses

A method of boosting a pre-existing immune response against non-typeable Haemophilus influenzae and Moraxella catarrhalis in a subject, the method comprising the step of administering an immunogenic composition comprising

• (i) protein D from Haemophilus influenzae (PD) or a fragment thereof having at least 85% identity to SEQ ID NO:
• 1,
• (ii) Protein E from Haemophilus influenzae (PE) or a fragment thereof having at least 85% identity to SEQ ID NO:
• 59,
• (iii) pilin A from Haemophilus influenza (PilA) or a fragment thereof having at least 85% identity to SEQ ID NO:
• 60,
• (iv) Ubiquitous surface protein A2 from Moraxella catarrhalis (UspA2) or a fragment thereof having at least 450, 490, 511, 534 or 535 contiguous amino acids of SEQ ID NO:
• 13, and
• (v) adjuvant 3-O-desacyl-4′-monophosphoryl lipid A (MPL), and a saponin QS 21 to the subject in an amount sufficient to elicit a further or additional, immune response relative to the pre-existing immune response, wherein the pre-existing immune response has been elicited by prior administration of at least two doses of the immunogenic composition and wherein the immunogenic composition is administered at least 6 months after administration of the first of the at least two doses of the immunogenic composition comprising
• (i) protein D from Haemophilus influenzae (PD) or a fragment thereof having 85% identity to SEQ ID NO:
• 1,
• (ii) Protein E from Haemophilus influenzae (PE) or a fragment thereof having 85% identity to SEQ ID NO:
• 59,
• (iii) pilin A from Haemophilus influenzae (PilA) or a fragment thereof having 85% identity to SEQ ID NO:
• 60,
• (iv) Ubiquitous surface protein A2 from Moraxella catarrhalis (UspA2) or a fragment thereof having at least 450, 490, 511, 534 or 535 contiguous amino acids of SEQ ID NO:
• 13, and
• (vi) adjuvant 3-O-desacyl-4′-monophosphoryl lipid A (MPL), and a saponin QS 21.