Evaluation of Safety and Tolerability of Tyrosine Adsorbed Ragweed Pollen Allergoid With MPL (Monophosphoryl Lipid A)

Inclusion Criteria: Non-smoker and not using any nicotine products Negative skin prick test with a standard panel of marker allergen extracts (including ragweed allergen extract) Specific IgE for ragweed with class = 0 No clinical history of IgE-mediated allergic diseases Subject agrees not to use any medication or herbal products during the study Males or non-pregnant, non-lactating females who are post-menopausal, naturally or surgically sterile, or who agree to use effective contraceptive methods throughout the course of the study. Subjects who are normally active and otherwise judged to be in good health on the basis of medical history, physical examination, routine laboratory tests and an infection screen Subjects must be willing and able to attend required study visits. Subjects must be able to follow instructions. Exclusion Criteria: Clinical history or presence of acute or subacute atopic dermatitis, chronic dermatitis, urticaria factitia, or urticaria due to physical/chemical influence. Clinical history or presence of diabetes, cancer or any clinically significant cardiac, respiratory, metabolic, renal, hepatic, gastrointestinal, dermatologic, venereal, hematologic, neurologic or psychiatric diseases or disorders. Any clinically significant (as determined by the Investigator) abnormal laboratory value at Visit 1 Clinical history of auto-immune diseases or rheumatoid diseases. Contraindication to adrenaline History of asthma Subject has used any prescription medications within 14 days or over-the-counter medications, including herbal products, within 2 days prior to Screening or will likely use any medication(s) or listed product(s) during the study. Subject has disorder of tyrosine metabolism Subject with diseases with a pathogenesis interfering with the immune response and who has received medication which could influence the results of this study Subject has acute or chronic infection Clinical history of anaphylaxis Clinical history of angioedema Clinical history of hypersensitivity to the excipients of the study medication History of immunotherapy with ragweed allergen extracts Current therapy with ß-blockers Currently receiving anti-allergy medication or other drugs with an antihistaminic activity Subject has a positive screen for cotinine or drugs of abuse at Visit 1 Subject has a positive saliva alcohol test at Visit 1 Subject participated in a clinical trial with a new chemical substance within the last 12 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 Clinically relevant abnormal vital signs or respiratory rate at the Screening Visit Subject received treatment with a preparation containing MPL® during the past 12 months.