title: Persistence of antibodies to meningococcal IgA1 protease versus decay of antibodies to group A polysaccharide and Opc protein.
abstract: Sera were taken over a 5 year period from Gambian children vaccinated in 1983, when aged 1-4 years, with A + C meningococcal capsular polysaccharide, ELISA tests were devised to determine the concentrations of immunoglobulin A, G and M reacting with A polysaccharide and of IgG reacting with Opc protein, IgA1 protease and an internal 104 mer peptide derived from IgA1 protease. Vaccination resulted in a brief rise of antibodies to A polysaccharide followed by decline to pre-immunization levels. IgM levels were very high even before vaccination. Antibodies to Opc protein stimulated by natural exposure also declined over the 5 year period. In contrast, antibodies stimulated by natural exposure to IgA1 protease or to the internal peptide remained constant or increased (final geometric mean level of 47 micrograms IgG ml-1). We speculate that healthy carriage of Neisseria meningitidis or Haemophilus influenzae is responsible for this increase in IgG concentration.
authors.affiliation: Max-Planck Institut für molekulare Genetik, Berlin, Germany.
authors.forename: B
authors.initials: B
authors.lastname: Thiesen
authors.forename: B
authors.initials: B
authors.lastname: Greenwood
authors.forename: N
authors.initials: N
authors.lastname: Brieske
authors.forename: M
authors.initials: M
authors.lastname: Achtman
mesh_terms: D000595:Amino Acid Sequence; D000907:Antibodies, Bacterial / Q000096:biosynthesis* / Q000097:blood; D000942:Antigens, Bacterial / Q000276:immunology; D000954:Antigens, Surface / Q000276:immunology; D001425:Bacterial Outer Membrane Proteins / Q000276:immunology*; D001428:Bacterial Vaccines / Q000276:immunology; D002675:Child, Preschool; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007074:Immunoglobulin G / Q000096:biosynthesis / Q000097:blood; D007223:Infant; D008969:Molecular Sequence Data; D009345:Neisseria meningitidis / Q000201:enzymology* / Q000276:immunology*; D011135:Polysaccharides, Bacterial / Q000276:immunology*; D012697:Serine Endopeptidases / Q000276:immunology*
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D000954:Antigens, Surface; D001425:Bacterial Outer Membrane Proteins; D001428:Bacterial Vaccines; D007074:Immunoglobulin G; D011135:Polysaccharides, Bacterial; C043226:meningococcal group A polysaccharide; C074517:opc protein, bacteria; D012697:Serine Endopeptidases; C021433:IgA-specific serine endopeptidase