Allergy vaccines: a need for standardisation in mass units of major allergen.

Treatment of respiratory allergies can be performed with allergen-specific immunotherapy using allergen extracts. These products are biologicals with an extremely complex and variable composition. Only a few components are of major importance for the disease, the so-called major allergens. At present, standardisation of allergen extracts is dominated by techniques that aim at establishing their overall IgE-binding potencies using pooled sera of allergic patients. Each company in the market uses its own type of units to express potencies, thus hampering comparability. Another disadvantage is that the major allergen composition is not determined. Most companies have introduced assays for the measurement of major allergens in their quality control systems, but these data are not yet used for labelling purposes. The need to include major allergen content in standardisation protocols is now widely accepted. To support future labelling on the basis of major allergen content the European Union has funded the multidisciplinary multicentre project CREATE. This project aims at developing international certified references for the most important major respiratory allergens and at evaluating the performance of available ELISA for their measurement. The project will facilitate expression of potencies by active ingredient (major allergen) content and will allow direct comparison of competitor products.