Standardization of mPEG-modified allergens.

Standardization of mPEG-modified allergens can be achieved by: standardization of allergens according to established principles; production of mPEG-modified allergens by a reproducible method; control of the batch-to-batch consistency by estimation of the allergenicity and the protein content in relation to the corresponding IHR and by determination of the degree of modification by estimation of the amount of PEG per unit allergen in the modified product. Standardization of mPEG-modified allergens should be looked upon only as a model for standardization of modified allergens. I hope that the authorities in Europe will set up strict and relevant criteria for the registration of similar products and also criteria for prolonging the registration of the older products without relevant standardization and documentation of safety and efficacy.