title: Are clinical trials required.
mesh_terms: D001241:Aspirin / Q000627:therapeutic use; D002986:Clinical Trials as Topic; D003139:Common Cold / Q000517:prevention & control; D004168:Diphtheria Toxoid; D004314:Down Syndrome / Q000188:drug therapy; D004341:Drug Evaluation; D006761:Hospitals; D006801:Humans; D007158:Immunologic Techniques; D008458:Measles Vaccine; D008889:Military Personnel; D009526:Nialamide / Q000627:therapeutic use; D010919:Placebos; D012107:Research Design; D014436:Typhoid-Paratyphoid Vaccines
chemical_list: D004168:Diphtheria Toxoid; D008458:Measles Vaccine; D010919:Placebos; D014436:Typhoid-Paratyphoid Vaccines; D001241:Aspirin; D009526:Nialamide