title: Persistence of antibodies for 42 months following vaccination of adolescents with a meningococcal serogroups A, C, W-135, and Y tetanus toxoid conjugate vaccine (MenACWY-TT).
abstract: OBJECTIVE
  A primary dose of the European Union (EU)-licensed meningococcal A, C, W-135, and Y tetanus toxoid conjugate vaccine (MenACWY-TT) was immunogenic and well-tolerated in subjects aged 15-19 years. This study assessed antibody persistence at 3.5 years after vaccination with a MenACWY-TT or a tetravalent ACWY polysaccharide vaccine (MenPS, control).
  
  
  METHODS
  In the original study, participants were randomized to receive a single dose of MenACWY-TT or MenPS. Serum bactericidal activity using rabbit serum as exogenous complement source was evaluated up to 42 months post-vaccination.
  
  
  RESULTS
  At 42 months post-vaccination with MenACWY-TT (n = 19) or MenPS (n = 17), all subjects in each group had serum bactericidal activity titers ≥1:8 against all serogroups, except for two subjects in the MenPS group against serogroup C. Geometric mean antibody titers were higher than pre-vaccination levels at all post-vaccination time-points in both groups, and were significantly higher in the MenACWY-TT group versus the MenPS group for serogroup W-135 at month 42 (exploratory analysis).
  
  
  CONCLUSIONS
  These results indicate that seroprotection following primary vaccination with MenACWY-TT extends more than 3 years. Ongoing persistence data are required to understand the duration of protection following vaccination and to guide decisions on the need for future booster doses.
authors.affiliation: Department of Infectious Diseases, Aarhus University Hospital, Brendstrupgårdsvej 100, 8200 Aarhus N, Denmark. larsoest@rm.dk
authors.forename: Lars
authors.initials: L
authors.lastname: Østergaard
authors.forename: Marie
authors.initials: M
authors.lastname: Van der Wielen
authors.forename: Veronique
authors.initials: V
authors.lastname: Bianco
authors.forename: Jacqueline M
authors.initials: JM
authors.lastname: Miller
mesh_terms: D000293:Adolescent; D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood*; D001770:Blood Bactericidal Activity / Q000276:immunology; D005260:Female; D006801:Humans; D008297:Male; D008589:Meningococcal Infections / Q000517:prevention & control*; D022401:Meningococcal Vaccines / Q000008:administration & dosage / Q000276:immunology*; D009345:Neisseria meningitidis / Q000276:immunology*; D011817:Rabbits; D013745:Tetanus Toxoid / Q000276:immunology; D014611:Vaccination; D055815:Young Adult
chemical_list: D000907:Antibodies, Bacterial; D022401:Meningococcal Vaccines; D013745:Tetanus Toxoid; C576777:tetravalent meningococcal serogroups A, C, W-135 and Y tetanus toxoid conjugate vaccine