title: Simultaneous aqueous ragweed extract and alum-precipitated pyridine ragweed extract used prophylactically.
mesh_terms: D000293:Adolescent; D000328:Adult; D000941:Antigens; D002648:Child; D003888:Desensitization, Immunologic; D005069:Evaluation Studies as Topic; D006801:Humans; D008875:Middle Aged; D010936:Plant Extracts / Q000008:administration & dosage; D010944:Plants; D011725:Pyridines / Q000008:administration & dosage*; D006255:Rhinitis, Allergic, Seasonal / Q000517:prevention & control*; D013997:Time Factors
chemical_list: D000941:Antigens; D010936:Plant Extracts; D011725:Pyridines