Patent ID: 8628809

Claim:
A method of inducing mucosal immune responses to an antigen in a subject in need thereof comprising administering to a mucosal site of said subject a vaccine comprising said antigen in combination with an adjuvant, wherein the Dioscorea polysaccharide (1) is characterized by a Fourier transform infrared (FT-IR) spectrum with peaks at 3000-2850 cm −1 , 1050-1020 cm −1 , 1085-1075 cm −1 , 1155-1150 cm −1 and 845-830 cm −1 , (2) is primarily composed of α-pyranosides and (3) is prepared by a process comprising the steps of: (a) eliminating small molecules by immersing a Dioscorea sp. in a 40% (v/v) alcoholic solution to obtain an insoluble solid portion; (b) de-starching the insoluble solid portion obtained in step (a) in a water solution by a starch-hydrolyzing enzyme to obtain an aqueous solution; (c) treating the aqueous solution obtained in step (b) with a 75% (v/v) alcoholic solution to obtain a precipitated solid portion including the Dioscorea polysaccharide; and (d) removing all protein substances from the precipitated solid portion obtained in step (c) with a deproteinizing agent.