The present invention provides T helper cell epitopes and compositions for use in inducing an immune response comprising at least one of these epitopes. The epitopes are contained within a peptide sequence selected from the group consisting of EPINQALTLMTKNVKPL (SEQ ID NO: 12); FAGVVLAGVALGVATAA (SEQ ID NO: 13); NLNAQAIQSLRTSLEQS (SEQ ID NO: 17) and TELLSIFGPSLRDPISA (SEQ ID NO: 20).