Abstract: The present invention relates to a composition comprising purified natural Der p1 and purified natural Der p2 allergens for use in the treatment of house-dust mite allergy in mammals, like humans. The invention further pertains pharmaceutical compositions for allergy-specific immune therapy. Specifically, the invention discloses reduced responsiveness to subsequent house dust mite allergen exposure after treatment with a pharmaceutical composition comprising purified natural Der p1 and purified natural Der p2 characterized by reduction in Th2 cell activity and reduction in CCL20 release.