title: Induction of immunological memory in UK infants by a meningococcal A/C conjugate vaccine.
abstract: The induction of immunological memory to serogroup A and C polysaccharides in UK infants immunized with three doses of a meningococcal A/C oligosaccharide CRM197 conjugate vaccine was investigated. Forty UK infants vaccinated previously with three doses of a meningococcal A/C oligosaccharide-CRM197 conjugate vaccine at 2, 3 and 4 months of age, were revaccinated at a mean age of 145.6 weeks with either a 10 or 50 microg dose of licensed meningococcal A/C polysaccharide vaccine. Serogroup-specific antibody and serum bactericidal antibody (SBA) responses were measured by enzyme-linked immunosorbent assay and serum bactericidal assays, respectively. Following challenge, anti-serogroup A and C polysaccharide antibody levels rose from pre-booster geometric mean concentrations (GMC) of 3.1 and 2.1 microg/ml respectively to 19.6 and 21.0 microg/ml 1 month post-booster. Serum bactericidal antibody geometric mean titres (GMTs) for serogroups A and C increased 156- and 113-fold from 2.1 and 7.1 pre-booster respectively to 327.4 and 800.7 post-booster. A serogroup A control group of 45 children received a 10 microg dose of licensed meningococcal A/C polysaccharide vaccine (with no prior history of serogroup A vaccination) had serogroup A SBA GMTs of 2.3 pre-vaccination rising to 8 post-vaccination with corresponding GMCs of 0.8 and 10.8 microg/ml. These rises in SBA following serogroup A/C conjugate vaccination are indicative of immunological priming.
authors.affiliation: Manchester Public Health Laboratory, Withington Hospital, UK.
authors.forename: R
authors.initials: R
authors.lastname: Borrow
authors.forename: A J
authors.initials: AJ
authors.lastname: Fox
authors.forename: P C
authors.initials: PC
authors.lastname: Richmond
authors.forename: S
authors.initials: S
authors.lastname: Clark
authors.forename: F
authors.initials: F
authors.lastname: Sadler
authors.forename: J
authors.initials: J
authors.lastname: Findlow
authors.forename: R
authors.initials: R
authors.lastname: Morris
authors.forename: N T
authors.initials: NT
authors.lastname: Begg
authors.forename: K A
authors.initials: KA
authors.lastname: Cartwright
mesh_terms: D000907:Antibodies, Bacterial / Q000032:analysis / Q000235:genetics; D001428:Bacterial Vaccines / Q000008:administration & dosage / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007115:Immunization Schedule; D007156:Immunologic Memory / Q000276:immunology*; D007223:Infant; D008297:Male; D008589:Meningococcal Infections / Q000276:immunology* / Q000517:prevention & control; D011135:Polysaccharides, Bacterial / Q000276:immunology*; D012703:Serotyping; D018074:Vaccines, Conjugate / Q000008:administration & dosage / Q000276:immunology*
chemical_list: D000907:Antibodies, Bacterial; D001428:Bacterial Vaccines; D011135:Polysaccharides, Bacterial; D018074:Vaccines, Conjugate