title: Seroprevalence and placental transmission of maternal antibodies specific for Neisseria meningitidis Serogroups A, C, Y and W135 and influence of maternal antibodies on the immune response to a primary course of MenACWY-CRM vaccine in the United Kingdom.
abstract: BACKGROUND
  Maternal antibodies give neonates some protection against bacterial infection. We measured antibodies against Neisseria meningitidis serogroups A, C, Y and W135 in mothers and their 2-month-old infants at study enrollment. We also assessed the impact of maternal antibody present at 2 months of age on the immune response to a primary course of quadrivalent meningococcal conjugate vaccine (MenACWY-CRM197) given at 2 and 4 months of age.
  
  
  METHODS
  This was a single-center, open-label, randomized study undertaken in Oxford, United Kingdom. Two hundred sixteen healthy infants were enrolled in the study and vaccinated with MenACWY-CRM197 at 2 and 4 months of age. Blood was obtained from all mothers, in a subset of infants at 2 months and all infants at 5 months. Antibody and memory B-cell responses at 5 months were correlated with maternal antibodies.
  
  
  RESULTS
  Mothers had low IgG antibodies against serogroups C, W135 and Y polysaccharides, but high serogroup A antibody, whereas 61-78% had protective human complement serum bactericidal activity (hSBA) (≥1:4) for serogroups C, W135 and Y but only 31% for serogroup A. Only 9%, 32%, 45% and 19% of 2-month-old infants had hSBA ≥1:4 for serogroups A, C, W135 and Y, respectively. Maternal antibody had little association on responses to MenACWY-CRM197, except a moderate negative association between MenC-specific bactericidal antibody at 2 and 5 months (r = -0.5, P = 0.006, n = 28) and between carrier-specific IgG antibody at 2 months and MenC-specific hSBA/IgG antibody at 5 months (r = -0.4, P = 0.02 and 0.04, n = 32 and 23). Nonetheless, 90% of infants achieved protective MenC-hSBA titers after vaccination at 2 and 4 months of age.
  
  
  CONCLUSIONS
  The levels of serogroup-specific meningococcal antibodies were low in mothers and 2-month-old infants. Immunizing mothers before or during pregnancy with meningococcal conjugate vaccines might increase antibody levels in early infancy and provide protection against infection due to N. meningitidis.
authors.affiliation: Oxford Vaccine Group, Department of Paediatrics, University of Oxford, Oxford, United Kingdom. Geraldine.BlanchardRohner@hcuge.ch
authors.forename: Geraldine
authors.initials: G
authors.lastname: Blanchard-Rohner
authors.forename: Matthew D
authors.initials: MD
authors.lastname: Snape
authors.forename: Dominic F
authors.initials: DF
authors.lastname: Kelly
authors.forename: Daniel
authors.initials: D
authors.lastname: O'Connor
authors.forename: Tessa
authors.initials: T
authors.lastname: John
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Kibwana
authors.forename: Hannah
authors.initials: H
authors.lastname: Parks
authors.forename: Karen
authors.initials: K
authors.lastname: Ford
authors.forename: Peter M
authors.initials: PM
authors.lastname: Dull
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Pollard
mesh_terms: D000907:Antibodies, Bacterial / Q000097:blood*; D001402:B-Lymphocytes / Q000737:chemistry / Q000276:immunology; D005260:Female; D006801:Humans; D007112:Immunity, Maternally-Acquired; D007156:Immunologic Memory; D007223:Infant; D022401:Meningococcal Vaccines / Q000008:administration & dosage* / Q000276:immunology*; D009345:Neisseria meningitidis / Q000276:immunology*; D010920:Placenta / Q000378:metabolism; D011247:Pregnancy; D016036:Seroepidemiologic Studies; D006113:United Kingdom; D014611:Vaccination / Q000379:methods
chemical_list: D000907:Antibodies, Bacterial; C556088:MenACWY-CRM vaccine; D022401:Meningococcal Vaccines