title: Chemoprophylaxis.
mesh_terms: D000208:Acute Disease; D002986:Clinical Trials as Topic; D003707:Demeclocycline / Q000627:therapeutic use*; D004196:Disease Outbreaks; D006801:Humans; D010919:Placebos; D011014:Pneumonia / Q000000981:diagnostic imaging / Q000517:prevention & control*; D011859:Radiography; D012141:Respiratory Tract Infections / Q000188:drug therapy*
chemical_list: D010919:Placebos; D003707:Demeclocycline