Assessment of Residual Allergenicity of Grass/Rye Pollen Allergoid Using Skin Prick Testing

Inclusion Criteria: * Positive skin prick test to grass and rye pollen allergen extract * Positive skin prick test to positive histamine control * Negative skin prick test to negative control * Specific IgE for grass and rye as documented by a RAST or equivalent test * Females of childbearing potential may enter the study if they have a negative urine pregnancy test and they have been practicing adequate contraception for 3 months prior to the study and continue to do so during the study. Exclusion Criteria: * History or presence of acute or subacute atopic dermatitis, chronic dermatitis, urticaria factitia, or urticaria due to physical/chemical influence or any other skin conditions which might interfere with the interpretation of skin prick test results * Visual inspection of the forearms indicates potential problems with the conduct or interpretation of the skin prick tests; both forearms must be available for testing * Subject has bronchial asthma or other lower respiratory tract condition (i.e., emphysema, bronchiectasis) * History or presence of diabetes, cancer or any clinically significant cardiac, metabolic, renal, hepatic, gastrointestinal, dermatologic, venereal, hematologic, neurologic or psychiatric diseases or disorders * Any clinically significant abnormal laboratory value at Visit 1 * Clinically relevant sensitivity to any common perennial allergen: house dust mites, molds, or epithelia (cat, dog, and horse). Sensitivity will be determined by a skin prick test at Visit 1, a RAST (or equivalent method) at Visit 1, or a documented history of symptoms to perennial allergens. Subjects may be enrolled in the study if they test positive, but have no current or historical symptoms to perennial allergens. * Clinically relevant sensitivity to any common springtime flowering plant: Birch, Oak, Sycamore, Beech, Ash, and Poplar. Sensitivity will be determined by a skin prick test at Visit 1, a RAST (or equivalent method) at Visit 1, or a documented history of symptoms to springtime (non-grass/rye) allergens. Subjects may be enrolled in the study if they test positive, but have no current or historical symptoms to these springtime allergens. * History of auto-immune diseases or rheumatoid diseases * Subject not allowed to receive adrenalin * Subject has disorder of tyrosine metabolism (i.e., alcaptonuria, tyrosinemia) * Subject with diseases interfering with the immune response and have received medication, which could influence the results of this study * Subject has acute or chronic infection * History of anaphylaxis, including anaphylactic food allergy, insect venom anaphylaxis, exercise or drug induced anaphylaxis * History of angioedema * History of hypersensitivity to the excipients of the study medication * History of immunotherapy with grass allergen extracts * Current therapy with ß-blockers * Currently receiving anti-allergy medication or other drugs with an antihistaminic activity * Subject has a positive drugs of abuse screen at Visit 1 * Subject participated in a clinical trial with an investigational drug within the last 3 months * Subject cannot communicate reliably with the Investigator or is not likely to cooperate with the requirements of the study * Subject is pregnant or lactating * Subject received treatment with a preparation containing MPL during the past 12 months * Use of prohibited medications or inadequate washout periods prior to screening