title: Antibody persistence, PRP-specific immune memory, and booster responses in infants immunised with a combination DTPa-HBV-IPV/Hib vaccine.
abstract: A new single-injection combination vaccine against six diseases has been developed to accommodate the growing number of recommended paediatric vaccines. A pentavalent liquid diphtheria, tetanus, acellular pertussis (3-component), hepatitis B, and inactivated polio (types 1-3) combined vaccine (DTPa-HBV-IPV) is extemporaneously mixed with a lyophilized Haemophilus influenza type B (Hib) conjugate vaccine (polyribosyl-ribitol phosphate (PRP)-T) and given as a single-injection. A cohort of 368 healthy infants was initially studied to evaluate the immunogenicity and reactogenicity of this hexavalent combination given as a primary course at 2, 4, and 6 months of age. At 15 months of age, from this cohort, 219 children received a booster dose of a licensed DTPa/Hib (PRP-T) vaccine to assess the booster response, while 70 received a challenge dose of unconjugated PRP (PRP) vaccine (to evaluate Hib-specific memory) plus a separate DTPa vaccine. Seven to 10 days following plain PRP challenge, anti-PRP geometric mean antibody concentrations (GMCs) had increased 13-fold to 5.67 microg/ml, and thirty days after conjugated PRP booster vaccination, anti-PRP antibody GMCs increased 102-fold. Both responses are indicative of immune memory. Vaccination was well tolerated following all primary and booster doses, although 10.5% of booster recipients experienced >50-mm local swelling at the site of DTPa vaccination. We conclude that DTPa-HBV-IPV/Hib is safe and immunogenic for primary vaccination, and that Hib-specific memory is induced by primary vaccination.
authors.affiliation: Murdoch Children's Research Institute, The University of Melbourne, Vic. 3010, Australia. t.nolan@unimelb.edu.au
authors.forename: T
authors.initials: T
authors.lastname: Nolan
authors.forename: A
authors.initials: A
authors.lastname: Altmann
authors.forename: M
authors.initials: M
authors.lastname: Skeljo
authors.forename: C
authors.initials: C
authors.lastname: Streeton
authors.forename: L
authors.initials: L
authors.lastname: Schuerman
mesh_terms: D000907:Antibodies, Bacterial / Q000032:analysis / Q000096:biosynthesis; D000914:Antibodies, Viral / Q000032:analysis / Q000096:biosynthesis; D015331:Cohort Studies; D015721:Diphtheria-Tetanus-Pertussis Vaccine / Q000008:administration & dosage / Q000009:adverse effects / Q000276:immunology*; D018073:Haemophilus Vaccines / Q000008:administration & dosage / Q000009:adverse effects / Q000276:immunology*; D017325:Hepatitis B Vaccines / Q000008:administration & dosage / Q000009:adverse effects / Q000276:immunology*; D006801:Humans; D007115:Immunization Schedule; D007117:Immunization, Secondary; D007156:Immunologic Memory; D007223:Infant; D007231:Infant, Newborn; D016037:Single-Blind Method; D013745:Tetanus Toxoid / Q000276:immunology; D017778:Vaccines, Combined / Q000276:immunology; D018074:Vaccines, Conjugate
chemical_list: D000907:Antibodies, Bacterial; D000914:Antibodies, Viral; D015721:Diphtheria-Tetanus-Pertussis Vaccine; D018073:Haemophilus Vaccines; D017325:Hepatitis B Vaccines; D013745:Tetanus Toxoid; D017778:Vaccines, Combined; D018074:Vaccines, Conjugate