Abstract: The present invention provides a chimeric polypeptide for reducing specific IgE binding to at least two house dust mite allergens in a subject, said chimeric polypeptide comprises an amino acid sequence comprising sequences of said at least two house dust mite allergens and wherein upon exposure to said allergens, said reduced binding causes reduced allergic reaction to said allergens in said subject.

Abstract: The invention provides a recombinant nucleic acid useful for inducing a protective immune response against an allergen. The recombinant nucleic acid encodes an allergen and a signal peptide that mediates the translocation of the allergen to endoplasmic reticulum and preferably also encodes a second signal peptide that targets the gene to an endosome or a lysosome. The recombinant nucleic acid, when administered to a subject induces a Th 1 type immunity and inhibits IgE production and therefore may be used to prevent and treat an allergic reaction. In various aspects therefore, the invention provides a vaccine and immunogenic composition comprising the recombinant nucleic acid.