How now, brown cow, vaccine or extract?

In summary, the word “allergen vaccine” should be used to denote FDA-approved preparations of therapeutic allergens used to treat allergic diseases. The term “allergen extract” should be used for preparations of allergens that are not yet FDA-approved, are FDA-approved but not yet incorporated into a therapeutic vaccine for an individual patient, or are used for experimental purposes. The term “diagnostic allergens”, in this case also approved by the FDA or its equivalent is appropriate when these products are used for skin testing. The use of these terms by physicians in allergy/immunology will enhance the specialty and be useful to patients who do not and never did understand the term “allergen extract”.