title: Re: "antitoxin responses in the elderly to tetanus-diphtheria (td) immunization".
mesh_terms: D000368:Aged; D000907:Antibodies, Bacterial / Q000032:analysis*; D003017:Clostridium tetani / Q000276:immunology*; D004165:Diphtheria / Q000517:prevention & control; D006801:Humans; D007114:Immunization; D013742:Tetanus / Q000276:immunology / Q000517:prevention & control*
chemical_list: D000907:Antibodies, Bacterial