The present invention relates generally to reagents useful in the immunotherapeutic or immunoprophylactic treatment of allergic diseases. More particularly, the present invention provides modified allergens exhibiting reduced IgE interactivity including reduced IgE production-stimulatory activity, while retaining T-cell antigenicity, which are useful in the immunomodulation of type I allergic disease conditions. The present invention further contemplates a method of immunomodulation of allergic diseases such as type I allergic disease conditions by the administration of modified allergens exhibiting reduced IgE interactivity while retaining T-cell antigenicity.