A protein consisting of the amino acid sequence set forth in SEQ ID NO. 1, a protein consisting of the amino acid sequence set forth in SEQ ID NO. 2, and/or an immunological equivalent thereof, for use in eliciting an immune response specific for red mites in a domestic animal, wherein the immunological equivalent is selected from a group consisting of (b) to (j) described below and is capable of eliciting Dermanyssus gallinae-specific immune response; (b) a protein consisting of an amino acid sequence in which one to several amino acids in the amino acid sequence set forth in SEQ ID NO. 1 are deleted or substituted and having an identity of at least 80% or higher with the amino acid sequence set forth in SEQ ID NO. 1, (c) a protein consisting of an amino acid sequence in which one to several amino acids are inserted in the amino acid sequence set forth in SEQ ID NO. land having an identity of at least 80% or higher with the amino acid sequence set forth in SEQ ID NO. 1, (f) a protein consisting of an amino acid sequence in which one to several amino acids in the amino acid sequence set forth in SEQ ID NO. 2 are deleted or substituted and having an identity of at least 80% or higher with the amino acid sequence set forth in SEQ ID NO. 2, (g) a protein consisting of an amino acid sequence in which one to several amino acids are inserted in the amino acid sequence set forth in SEQ ID NO. 2 and having an identity of at least 80% or higher with the amino acid sequence set forth in SEQ ID NO. 2, (i) a polypeptide fragment of the proteins consisting of the amino acid sequence set forth in SEQ ID NO. 1 or SEQ ID No. 2, or the proteins of the above (b) to (g), wherein the polypeptide fragment has no less than 30 amino acid residues, and (j) a protein consisting of an amino acid sequence in which an optional amino acid (s) is/are added at the N- and/or C-terminus of the amino acid sequence of SEQ ID No. 1 or SEQ ID No. 2, or any one of the amino acid sequence defined in the above (b) to (i). (b) a protein consisting of an amino acid sequence in which one to several amino acids in the amino acid sequence set forth in SEQ ID NO. 1 are deleted or substituted and having an identity of at least 80% or higher with the amino acid sequence set forth in SEQ ID NO. 1, (c) a protein consisting of an amino acid sequence in which one to several amino acids are inserted in the amino acid sequence set forth in SEQ ID NO. land having an identity of at least 80% or higher with the amino acid sequence set forth in SEQ ID NO. 1, (f) a protein consisting of an amino acid sequence in which one to several amino acids in the amino acid sequence set forth in SEQ ID NO. 2 are deleted or substituted and having an identity of at least 80% or higher with the amino acid sequence set forth in SEQ ID NO. 2, (g) a protein consisting of an amino acid sequence in which one to several amino acids are inserted in the amino acid sequence set forth in SEQ ID NO. 2 and having an identity of at least 80% or higher with the amino acid sequence set forth in SEQ ID NO. 2, (i) a polypeptide fragment of the proteins consisting of the amino acid sequence set forth in SEQ ID NO. 1 or SEQ ID No. 2, or the proteins of the above (b) to (g), wherein the polypeptide fragment has no less than 30 amino acid residues, and (j) a protein consisting of an amino acid sequence in which an optional amino acid (s) is/are added at the N- and/or C-terminus of the amino acid sequence of SEQ ID No. 1 or SEQ ID No. 2, or any one of the amino acid sequence defined in the above (b) to (i).