The present disclosure provides a composition for the prophylaxis or treatment of diseases (e.g., infectious disease, allergy or autoimmune disease). The present disclosure provides a composition, a medicament, a kit, and the like for the prophylaxis or treatment of the disease of a test subject. The composition, medicament, kit, and the like contain a non-causative factor antigen component that is neither derived from nor cross-reactive with the causative factor of the disease, and is administered under conditions where a causative factor antigen component derived from and/or cross-reactive with a causative factor of the target disease is present in the target.