[Study on early immunity to diphtheria in premature infants].
D004165:Diphtheria / Q000276:immunology*; D004168:Diphtheria Toxoid; D005500:Follow-Up Studies; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D014611:Vaccination
D004168:Diphtheria Toxoid