Abstract: The present invention provides D39-derived mutant PspA that does not undergo deamination and maintains stability as a molecule even around neutral pH range. Specifically, the present invention relates to a protein of the following (a) or (b): (a) a protein comprising the amino acid sequence as set forth in SEQ ID NO: 2 and having pneumococcal vaccine antigenic activity, and a protein substantially identical to the protein; or (b) a protein being a part of the amino acid sequence as set forth in SEQ ID NO: 2, wherein aspartic acid at position 254 is comprised in the part, and having pneumococcal vaccine antigenic activity, and a protein substantially identical to the protein.

Abstract: It is an object of the present invention to provide: a complex of an antigen that is not encapsulated in a nanogel, and a nanogel; and a vaccine preparation comprising the complex.

Abstract: The present invention provides a nanogel nasal vaccine that induces cell-mediated immunity. The present invention relates to a vaccine preparation comprising a complex of a nanogel, a vaccine antigen, and an adjuvant, wherein the vaccine preparation can efficiently induce the cell-mediated immunity, and can also induce a systemic and mucosal immune response.

Abstract: The present invention provides D39-derived mutant PspA that does not undergo deamination and maintains stability as a molecule even around neutral pH range. Specifically, the present invention relates to a protein of the following (a) or (b): (a) a protein comprising the amino acid sequence as set forth in SEQ ID NO: 2 and having pneumococcal vaccine antigenic activity, and a protein substantially identical to the protein; or (b) a protein being a part of the amino acid sequence as set forth in SEQ ID NO: 2, wherein aspartic acid at position 254 is comprised in the part, and having pneumococcal vaccine antigenic activity, and a protein substantially identical to the protein.

Abstract: The present invention provides a nanogel nasal vaccine that induces cell-mediated immunity. Specifically, the present invention relates to a vaccine preparation comprising a complex of a nanogel, a vaccine antigen, and an adjuvant, wherein the vaccine preparation can efficiently induce the cell-mediated immunity, and can also induce a systemic and mucosal immune response.