title: The fiftieth anniversary of diphtheria and tetanus immunization.
mesh_terms: D002170:Canada; D004165:Diphtheria / Q000266:history*; D004168:Diphtheria Toxoid; D005060:Europe; D049672:History, 19th Century; D049673:History, 20th Century; D006801:Humans; D007114:Immunization / Q000266:history*; D007115:Immunization Schedule; D007117:Immunization, Secondary; D013742:Tetanus / Q000266:history*; D013745:Tetanus Toxoid; D014481:United States; D014612:Vaccines / Q000266:history
chemical_list: D004168:Diphtheria Toxoid; D013745:Tetanus Toxoid; D014612:Vaccines