title: Five-year Antibody Persistence and Booster Response After 1 or 2 Doses of Meningococcal A, C, W and Y Tetanus Toxoid Conjugate Vaccine in Healthy Children.
abstract: We evaluated antibody persistence up to 5 years postvaccination with a quadrivalent meningococcal serogroups A, C, W and Y tetanus toxoid conjugate vaccine (MenACWY-TT), and subsequent booster responses to MenACWY-TT in healthy US children.
  
  
  
  In the initial phase II, open, multicenter study (NCT00471081), 349 infants were randomized (1:1) to receive MenACWY-TT (1 or 2 doses). In the follow-up study (NCT00718666), we evaluated antibody persistence at years 1, 3 and 5 by serum bactericidal assay using human complement (hSBA). At year 5, children received a booster dose of MenACWY-TT. We compared their immune responses at 1 month postbooster with those from 100 age-matched, meningococcal naive children, who received a primary MenACWY-TT dose. We recorded solicited adverse events for 4 days and unsolicited adverse events for 31 days, followed by an additional 5-month extended safety follow-up.
  
  
  
  At year 5, ≥64.0% of 1-dose and ≥74.6% of 2-dose recipients had hSBA titers ≥8 for MenC, MenW and MenY. For MenA, 31.7% of 1-dose and 38.0% of 2-dose recipients had hSBA titers ≥8. One month postvaccination, all booster dose recipients and ≥78.5% of primary dose recipients exhibited hSBA titers ≥8 for all serogroups. Geometric mean titers were higher in primed than in naive children. MenACWY-TT had a clinically acceptable safety profile.
  
  
  
  With the exception of serogroup W, antibody persistence 5 years after MenACWY-TT vaccination did not differ substantially between children who received 1 or 2 doses in infancy. A booster dose of MenACWY-TT elicited robust anamnestic responses and was well tolerated.
authors.affiliation: From the *Kaiser Permanente Vaccine Study Center, Kaiser Permanente Northern California Division of Research, Oakland, California; †Vaccines R&D, and ‡Late Clinical Research and Development, GSK Vaccines, King of Prussia, Pennsylvania; §Biometrics, GSK Vaccines, Bangalore, India; and ¶Vaccine Discovery and Development, GSK Vaccines, Wavre, Belgium.
authors.forename: Nicola P
authors.initials: NP
authors.lastname: Klein
authors.forename: Yaela
authors.initials: Y
authors.lastname: Baine
authors.forename: Devayani
authors.initials: D
authors.lastname: Kolhe
authors.forename: Carmen I
authors.initials: CI
authors.lastname: Baccarini
authors.forename: Jacqueline M
authors.initials: JM
authors.lastname: Miller
authors.forename: Marie
authors.initials: M
authors.lastname: Van der Wielen
mesh_terms: D000907:Antibodies, Bacterial / Q000097:blood*; D001770:Blood Bactericidal Activity; D002648:Child; D002675:Child, Preschool; D064420:Drug-Related Side Effects and Adverse Reactions / Q000453:epidemiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007117:Immunization, Secondary; D007223:Infant; D008297:Male; D022401:Meningococcal Vaccines / Q000008:administration & dosage / Q000009:adverse effects / Q000276:immunology*; D014481:United States
chemical_list: D000907:Antibodies, Bacterial; D022401:Meningococcal Vaccines; C576777:tetravalent meningococcal serogroups A, C, W-135 and Y tetanus toxoid conjugate vaccine