A complex comprising a Class II HLA-DRB1*03 or Class II HLA-DRB1*13 molecule bound to a peptide, wherein the peptide comprises the amino acid sequence HTYTIDWTKDAVTWS or a portion thereof, or a variant of the given amino acid sequence or portion wherein the side chains of one or two or three or four or five or six or seven of the amino acid residues are altered, wherein the peptide comprising the portion, or variant, is capable of binding HLA-DRB1*03 and/or HLA-DRB1*13. The complex may be used to select Aspergillus and Candida antigen-specific T cells. A vaccine against Candida albicans infection comprising (a) a peptide comprising the amino acid sequence HTYTIDWTKDAVTWS or a portion thereof, or a variant of the given amino acid sequence or portion wherein the side chains of one or two or three or four or five or six or seven of the amino acid residues are altered, wherein the peptide comprising the portion, or variant, is capable of binding HLA-DRB1*03 and/or HLA-DRB1*04 and/or HLA-DRB1*13, or (b) a polypeptide which is a fusion of any of the peptides of (a) and another peptide, or (c) a polynucleotide encoding a peptide of (a) or a polypeptide of (b) or (d) an expression vector capable of expressing a peptide of (a) or a polypeptide of (b). A peptide of less than 10 000 molecular weight comprising the amino acid sequence HTYTIDWTKDAVTWS or a portion thereof or a variant of the given amino acid sequence or portion wherein the side chains of one or two or three or four or five or six or seven of the amino acid residues are altered, wherein the peptide comprising the portion, or variant, is capable of binding HLA-DRB1*03 and/or HLA-DRB1*13,
