Specific allergen immunotherapy as currently practiced in the USA and described in product labeling comprises the subcutaneous injection of incrementally increasing doses to a targeted maintenance dose ("build-up") followed by maintenance injections of allergenic extract/vaccine. Up to 30-40 injections may be required during the build-up phase over a 3-6 month period. When adequate maintenance doses are reached, this form of immunotherapy (SCIT) has been shown to be highly effective and safe.