title: Influence of high titers of maternal antibody on the serologic response of infants to diphtheria vaccination at three, five and twelve months of age.
abstract: Diphtheria antitoxin was determined in serum from 44 pregnant women, of whom 26 had received one injection of diphtheria toxoid during pregnancy. Their infants were vaccinated with a combined diphtheria-tetanus vaccine at 3, 5 and 12 months of age. This vaccination schedule has been used in Sweden since 1986, replacing the old schedule of vaccination at 3, 4.5 and 6 months of age originally designed for diphtheria-tetanus-pertussis vaccine, which had not been used after cessation of general vaccination against pertussis in 1979. Serum samples from the infants were obtained at 3, 7 and 18 months of age. After 2 injections infants of mothers with high antitoxin titers, > or = 0.1 IU/ml, tended to have lower antitoxin titers than infants of mothers with low antitoxin concentrations (P = 0.067). All children had, however, antitoxin above the minimum protective level of 0.01 IU/ml. Median antitoxin titers were 1.6 IU/ml in both groups after the third booster injection. Four infants of mothers who had been vaccinated during pregnancy and who had titers of > or = 0.4 IU/ml did not reach the 0.1 IU/ml level after 2 injections: all 4 responded with high antitoxin titers after the third dose. Thus all infants were primed by 2 doses of vaccine, irrespective of maternal antibody concentration. The repressive effect of maternal antibody on titers noted after 2 doses was no longer observed after the third, booster dose.
authors.affiliation: Department of Infectious Diseases, Göteborg University, Ostra Hospital, Sweden.
authors.forename: B
authors.initials: B
authors.lastname: Björkholm
authors.forename: M
authors.initials: M
authors.lastname: Granström
authors.forename: J
authors.initials: J
authors.lastname: Taranger
authors.forename: M
authors.initials: M
authors.lastname: Wahl
authors.forename: L
authors.initials: L
authors.lastname: Hagberg
mesh_terms: D000914:Antibodies, Viral / Q000032:analysis / Q000097:blood*; D003353:Corynebacterium diphtheriae / Q000276:immunology*; D004165:Diphtheria / Q000276:immunology* / Q000517:prevention & control; D004168:Diphtheria Toxoid / Q000276:immunology* / Q000627:therapeutic use; D005260:Female; D005312:Fetal Blood / Q000276:immunology; D006801:Humans; D007112:Immunity, Maternally-Acquired; D007115:Immunization Schedule; D007117:Immunization, Secondary; D007223:Infant; D007231:Infant, Newborn; D011247:Pregnancy / Q000276:immunology; D012044:Regression Analysis; D013548:Sweden
chemical_list: D000914:Antibodies, Viral; D004168:Diphtheria Toxoid