title: Passively acquired anti-tetanus and anti-Haemophilus antibodies and the response to Haemophilus influenzae type b-tetanus toxoid conjugate vaccine in infancy.
abstract: OBJECTIVE
  To study the influence of maternally inherited tetanus antitoxin (anti-TT) antibodies on the response to the Haemophilus influenzae type b (Hib) capsular polysaccharide (PS)-tetanus toxoid conjugate (PRP-T) vaccine.
  
  
  METHODS
  One hundred thirty healthy infants received their first dose of PRP-T in the same syringe with diphtheria-tetanus-pertussis vaccine (DTP) at 1 to 2 months, and 66 of them received a second dose at 3 to 4 months of age.
  
  
  RESULTS
  Maternal anti-TT antibodies did not interfere with the anti-Hib PS response to the first PRP-T vaccination; the geometric mean concentration (GMC) of anti-Hib PS was 0.14 microgram/ml in those with the lowest preimmunization anti-TT (< 0.3 IU/ml, n = 15) and 0.13 microgram/ml in those with the highest anti-TT (> or = 3 IU/ml, n = 25). After the second dose of PRP-T there was a positive correlation (r = 0.37, P = 0.004) between the anti-Hib PS response and the preimmunization anti-TT; those with the lowest preimmunization anti-TT (< 0.3 IU/ml, n = 9) achieved GMC of anti-Hib PS of 1.22 micrograms/ml and those with anti-TT > or = IU/ml (n = 22) anti-Hib PS GMC of 2.67 micrograms/ml. High preimmunization anti-Hib PS antibodies did not interfere with the final antibody concentrations; the GMC of anti-Hib PS after the second dose of PRP-T was 1.60 micrograms/ml in those with a preimmunization titer > or = 1.0 microgram/ml (n = 12) and 1.57 micrograms/ml in those with a titer of < 1.0 microgram/ml (n = 53).
  
  
  CONCLUSIONS
  The data suggest that infants can be safely vaccinated with PRP-T even though they have received high concentrations of anti-TT from their mother.
authors.affiliation: National Public Health Institute, Helsinki, Finland.
authors.forename: S
authors.initials: S
authors.lastname: Kurikka
authors.forename: R M
authors.initials: RM
authors.lastname: Olander
authors.forename: J
authors.initials: J
authors.lastname: Eskola
authors.forename: H
authors.initials: H
authors.lastname: Käyhty
mesh_terms: D000907:Antibodies, Bacterial / Q000032:analysis / Q000096:biosynthesis*; D006190:Haemophilus / Q000276:immunology*; D006193:Haemophilus influenzae / Q000276:immunology*; D006801:Humans; D007110:Immunity, Active; D007112:Immunity, Maternally-Acquired; D007121:Immunocompetence; D007223:Infant; D013742:Tetanus / Q000276:immunology*; D013745:Tetanus Toxoid / Q000276:immunology*; D018074:Vaccines, Conjugate / Q000008:administration & dosage* / Q000276:immunology*
chemical_list: D000907:Antibodies, Bacterial; D013745:Tetanus Toxoid; D018074:Vaccines, Conjugate