This peptide/²-1,3-glucan complex includes ²-1,3-glucan and a peptide/polynucleotide conjugate in which an antigenic peptide is bonded covalently to a polynucleotide or a derivative thereof. The polynucleotide or derivative thereof of the peptide/polynucleotide conjugate bonds via a hydrogen bond with ²-1,3-glucan, forming a complex having a triple helix structure including a single molecular chain of the polynucleotide or derivative thereof and two molecular chains of the ²-1,3-glucan. Alternatively, the side chain of the ²-1,3-glucan and the antigenic peptide are bonded covalently formed by either a cycloaddition reaction between an alkyne and an azide derivative, or a reaction between a maleimide group or a vinyl sulfone group and a thiol group.
