The induction of immunologic memory after vaccination with Haemophilus influenzae type b conjugate and acellular pertussis-containing diphtheria, tetanus, and pertussis vaccine combination.
The significance of reduced antibody responses to the Haemophilus influenzae type b (Hib) component of acellular pertussis-containing combination vaccines (DTaP-Hib) is unclear. A DTaP-Hib vaccine evaluated in infants vaccinated at ages 2, 3, and 4 months showed reduced anti-Hib polysaccharide IgG (geometric mean concentration [GMC], 1.23 microgram/mL; 57%, >1.0 microgram/mL). Polyribitolribosyl phosphate (PRP) and Hib conjugate (PRP-T) vaccine given as a booster during the second year of life was evaluated for the presence of immunological memory. After boosting, most children achieved anti-PRP IgG >1.0 microgram/mL, although the GMC was higher with PRP-T (88.5 microgram/mL) than with PRP vaccine (7.86 microgram/mL, P<.001). The GMC of the PRP group was higher than anticipated for naive PRP recipients of the same age. PRP-specific IgG avidity was significantly higher after boosting than after priming, providing further evidence for the generation of memory. Despite reduced immunogenicity, DTaP-Hib combination vaccines appear to prime for immunologic memory.
Immunobiology Unit, Institute of Child Health, London WC1N 1EH, UK. d.goldblatt@ich.ucl.ac.uk
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D
Goldblatt
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Richmond
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Millard
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Thornton
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Miller
D000907:Antibodies, Bacterial / Q000097:blood; D000915:Antibody Affinity; D015721:Diphtheria-Tetanus-Pertussis Vaccine / Q000276:immunology*; D022681:Diphtheria-Tetanus-acellular Pertussis Vaccines; D018073:Haemophilus Vaccines / Q000276:immunology*; D019741:Haemophilus influenzae type b / Q000276:immunology*; D006801:Humans; D007117:Immunization, Secondary; D007156:Immunologic Memory; D007223:Infant; D011134:Polysaccharides / Q000276:immunology; D013745:Tetanus Toxoid / Q000276:immunology*; D017778:Vaccines, Combined / Q000276:immunology; D018074:Vaccines, Conjugate / Q000276:immunology*
D000907:Antibodies, Bacterial; D015721:Diphtheria-Tetanus-Pertussis Vaccine; D022681:Diphtheria-Tetanus-acellular Pertussis Vaccines; D018073:Haemophilus Vaccines; C055753:Haemophilus influenza type b polysaccharide vaccine-tetanus toxin conjugate; D011134:Polysaccharides; D013745:Tetanus Toxoid; D017778:Vaccines, Combined; D018074:Vaccines, Conjugate; C008984:polyribitol phosphate