title: Humoral immune responses to Neisseria meningitidis in children.
abstract: An understanding of the nature of immunity to serogroup B meningococci in childhood is necessary in order to establish the reasons for poor responses to candidate vaccines in infancy. We sought to examine the nature of humoral immune responses following infection in relation to age. Serum bactericidal activity was poor in children under 12 months of age despite recent infection with Neisseria meningitidis. The highest levels of bactericidal activity were seen in children over 10 years of age. However, infants produced levels of total immunoglobulin G (IgG) and IgG subclass antibodies similar to those in older children in a meningococcal enzyme-linked immunosorbent assay. Most antibody was of the IgG1 and IgG3 subclasses. This striking age dependency of bactericidal antibody response following infection is not apparently due to failure of class switching in infants but might be due to qualitative differences in antibody specificity or affinity.
authors.affiliation: Departments of Paediatrics and Infectious Diseases & Microbiology, Imperial College School of Medicine, St. Mary's Hospital, London W2 1PG, United Kingdom. AJPollard@csi.com
authors.forename: A J
authors.initials: AJ
authors.lastname: Pollard
authors.forename: R
authors.initials: R
authors.lastname: Galassini
authors.forename: E M
authors.initials: EM
authors.lastname: van der Voort
authors.forename: R
authors.initials: R
authors.lastname: Booy
authors.forename: P
authors.initials: P
authors.lastname: Langford
authors.forename: S
authors.initials: S
authors.lastname: Nadel
authors.forename: C
authors.initials: C
authors.lastname: Ison
authors.forename: J S
authors.initials: JS
authors.lastname: Kroll
authors.forename: J
authors.initials: J
authors.lastname: Poolman
authors.forename: M
authors.initials: M
authors.lastname: Levin
mesh_terms: D000328:Adult; D000367:Age Factors; D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood*; D001428:Bacterial Vaccines / Q000276:immunology; D001770:Blood Bactericidal Activity; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D003165:Complement System Proteins / Q000276:immunology; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood / Q000145:classification; D007223:Infant; D008585:Meningitis, Meningococcal / Q000276:immunology / Q000517:prevention & control; D008589:Meningococcal Infections / Q000276:immunology* / Q000517:prevention & control; D022401:Meningococcal Vaccines; D009345:Neisseria meningitidis / Q000145:classification / Q000276:immunology*; D011817:Rabbits; D012703:Serotyping
chemical_list: D000907:Antibodies, Bacterial; D001428:Bacterial Vaccines; D007074:Immunoglobulin G; D022401:Meningococcal Vaccines; D003165:Complement System Proteins