title: Safety and immunogenicity of a Haemophilus influenzae type B polysaccharide-tetanus toxoid conjugate vaccine combined with diphtheria, tetanus and pertussis vaccines in Thai infants.
abstract: A randomized, open, multicenter trial was conducted to determine the safety and immunogenicity of a Haemophilus influenzae type b polysaccharide-tetanus toxoid (PRP-T) conjugate vaccine combined with tetanus, diphtheria and pertussis (DTP) vaccine in 271 Thai infants born to mothers immunized against tetanus during pregnancy. Infants were immunized at approximately 2, 4 and 6 months of age with these vaccines. To determine if elevated levels of anti-tetanus toxin antibodies suppressed the anti-PRP antibody response, a second group of infants were immunized with PRP complexed with outer membrane proteins of Neisseria meningitidis (Pedvax HIB) in one limb at 2 and 4 months of age and DTP vaccine in the other limb at 2, 4 and 6 months of age. A third group of infants received only DTP vaccine at 2, 4 and 6 months of age. The occurrence of both local and systemic adverse reactions were comparable in all 3 groups. The geometric mean anti-tetanus antibody titer was > 1 IU/ml at baseline. Approximately 1 month after the administration of the third dose of vaccine, 98.5%, 99.3% and 9.7% of the children immunized with DTP+Pedvax HIB, DTP-PRP-T or DTP possessed > or = 0.15 microgram of anti-PRP antibody per ml. No child in the DTP group achieved > or = 1 microgram/ml while 74.2% and 89.3% did so after immunization with DTP+Pedvax HIB, or DTP-PRP-T, respectively (p < 0.05). Immune responses to diphtheria, tetanus and pertussis antigens were similar in all vaccine groups. These results demonstrate that elevated tetanus antibody titers do not diminish the anti-PRP antibody response following immunization with a PRP-T conjugate combined with DTP vaccine.
authors.affiliation: Children's Hospital, Bangkok, Thailand.
authors.forename: T
authors.initials: T
authors.lastname: Chotpitayasunondh
authors.forename: C
authors.initials: C
authors.lastname: Panpitpat
authors.forename: U
authors.initials: U
authors.lastname: Thisyakorn
authors.forename: E
authors.initials: E
authors.lastname: Furer
authors.forename: J U
authors.initials: JU
authors.lastname: Que
authors.forename: T
authors.initials: T
authors.lastname: Hasler
authors.forename: S J
authors.initials: SJ
authors.lastname: Cryz
mesh_terms: D000907:Antibodies, Bacterial / Q000097:blood; D016667:Bacterial Capsules; D001425:Bacterial Outer Membrane Proteins / Q000009:adverse effects / Q000276:immunology; D015721:Diphtheria-Tetanus-Pertussis Vaccine / Q000009:adverse effects / Q000276:immunology*; D005260:Female; D018073:Haemophilus Vaccines / Q000009:adverse effects / Q000276:immunology*; D006801:Humans; D017589:Immunization Programs; D007115:Immunization Schedule; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D011135:Polysaccharides, Bacterial / Q000009:adverse effects / Q000276:immunology*; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D013745:Tetanus Toxoid / Q000009:adverse effects / Q000276:immunology*; D013785:Thailand; D017778:Vaccines, Combined / Q000009:adverse effects / Q000276:immunology; D018074:Vaccines, Conjugate / Q000009:adverse effects / Q000276:immunology
chemical_list: D000907:Antibodies, Bacterial; D001425:Bacterial Outer Membrane Proteins; D015721:Diphtheria-Tetanus-Pertussis Vaccine; D018073:Haemophilus Vaccines; C044237:Haemophilus influenzae type b polysaccharide vaccine; C061964:Haemophilus influenzae-type b polysaccharide-Neisseria meningitidis outer membrane protein conjugate vaccine; D011135:Polysaccharides, Bacterial; D013745:Tetanus Toxoid; D017778:Vaccines, Combined; D018074:Vaccines, Conjugate