title: Immunogenicity and immune memory of a nonadjuvanted quadrivalent meningococcal glycoconjugate vaccine in infants.
abstract: BACKGROUND
  The highest rate of invasive meningococcal disease is among children under 2 years of age. There is currently no licensed quadrivalent (serogroups A, C, W-135, and Y) meningococcal glycoconjugate vaccine approved for infants. We evaluated the immunogenicity and reactogenicity of a novel quadrivalent nonadjuvanted meningococcal glycoconjugate vaccine (MenACWY-CRM) in healthy infants.
  
  
  METHODS
  One hundred eighty infants (90 in Canada and 90 in the United Kingdom) received 2 doses of MenACWY-CRM at 2 and 4 months of age administered concomitantly with routine infant vaccines. At 12 months of age, the Canadian infants received either MenACWY-CRM or a reduced dose of a licensed meningococcal polysaccharide vaccine. In the United Kingdom, all infants received a further dose of MenACWY-CRM. The serological marker of protection was a titer of > or =1:4 using a serum bactericidal assay with human complement (hSBA).
  
  
  RESULTS
  Two doses of MenACWY-CRM induced hSBA titers > or =1:4 in 57% (95% confidence interval [CI]: 45-67) and 50% (95% CI: 38-62) of infants against serogroup A in Canada and the United Kingdom, respectively, 93% (95% CI: 85-97) and 86% (95% CI: 46-93) against serogroup C, 95% (95% CI: 87-99) and 82% (95% CI: 71-90) against serogroup W-135, and 91% (95% CI: 82-96) and 74% (95% CI: 63-83) against serogroup Y. After a booster dose of MenACWY-CRM at 12 months, at least 94% of participants achieved hSBA titers > or =1:4 against each of the serogroups C, W-135, and Y and more than 79% against serogroup A. The vaccine was well tolerated.
  
  
  CONCLUSIONS
  The nonadjuvanted MenACWY-CRM is immunogenic and well tolerated in infancy and could provide broad protection against meningococcal disease in this vulnerable age group.
authors.affiliation: Oxford Vaccine Group, Department of Paediatrics, University of Oxford, Centre for Vaccinology and Tropical Medicine, Churchill Hospital, Oxford, UK. Kirsten.perrett@paediatrics.ox.ac.uk
authors.forename: Kirsten P
authors.initials: KP
authors.lastname: Perrett
authors.forename: Matthew D
authors.initials: MD
authors.lastname: Snape
authors.forename: Karen J
authors.initials: KJ
authors.lastname: Ford
authors.forename: Tessa M
authors.initials: TM
authors.lastname: John
authors.forename: Ly-Mee M
authors.initials: LM
authors.lastname: Yu
authors.forename: Joanne M
authors.initials: JM
authors.lastname: Langley
authors.forename: Shelly
authors.initials: S
authors.lastname: McNeil
authors.forename: Peter M
authors.initials: PM
authors.lastname: Dull
authors.forename: Francesca
authors.initials: F
authors.lastname: Ceddia
authors.forename: Alessandra
authors.initials: A
authors.lastname: Anemona
authors.forename: Scott A
authors.initials: SA
authors.lastname: Halperin
authors.forename: Simon
authors.initials: S
authors.lastname: Dobson
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Pollard
mesh_terms: D000276:Adjuvants, Immunologic; D000907:Antibodies, Bacterial / Q000097:blood*; D005260:Female; D006801:Humans; D007156:Immunologic Memory; D007223:Infant; D008297:Male; D008589:Meningococcal Infections / Q000276:immunology / Q000517:prevention & control*; D022401:Meningococcal Vaccines / Q000008:administration & dosage / Q000009:adverse effects / Q000276:immunology*; D009345:Neisseria meningitidis / Q000145:classification / Q000276:immunology; D012703:Serotyping; D016896:Treatment Outcome; D018074:Vaccines, Conjugate / Q000008:administration & dosage / Q000009:adverse effects / Q000276:immunology*
chemical_list: D000276:Adjuvants, Immunologic; D000907:Antibodies, Bacterial; D022401:Meningococcal Vaccines; D018074:Vaccines, Conjugate