Universal T-cell epitopes for anti-malarial vaccines

An immunogenic composition which comprises a first peptide comprising a universal T-cell epitope, wherein said universal T-cell epitope:

• (a) is a sequence of contiguous amino acids as present in a sequence of a circumsporozoite (CS) protein of a plasmodial species, said epitope sequence (i) having a length and alignment of a motif of aliphatic and aromatic amino acid residues which are identical to the length and alignment of the motif of amino acid residues in positions corresponding to residues 2, 3, 6, 10, and 14 of a sequence EYLNKIQNSLSTEWSPCSVT (SEQ ID NO:3) or (ii) corresponding in length and alignment to SEQ ID NO:3 as present in P. falciparum NF54 strain CS protein;
• (b) is not contiguous in the first peptide with any amino acid sequence which is immediately adjacent to the sequence of the epitope in the sequence of the CS protein of the plasmodial species;
• and
• (c) binds many diverse major histocompatability complex (MHC) Class II molecules;
• wherein said composition elicits an anti-CS parasite-specific T-cell response in humans of diverse human leukocyte antigen (HLA) genetic backgrounds.