title: Randomized trial to assess the immunogenicity, safety and antibody persistence up to three years after a single dose of a tetravalent meningococcal serogroups A, C, W-135 and Y tetanus toxoid conjugate vaccine in toddlers.
abstract: Effective vaccines offering broad protection to toddlers, who are at high risk for invasive meningococcal disease, are needed. Here, the immunogenicity, safety and antibody persistence of the tetravalent meningococcal ACWY tetanus toxoid conjugate vaccine (MenACWY-TT) were evaluated in toddlers. Healthy participants aged 12 to 23 mo (n = 304) were randomized (3:1) to receive one dose of MenACWY-TT or a monovalent meningococcal serogroup C conjugate vaccine (MenC-CRM 197). Serum bactericidal activity was evaluated with assays using rabbit (rSBA) and human (hSBA) complement up to three years post-vaccination. MenACWY-TT was demonstrated to be non-inferior to MenC-CRM 197 in terms of immunogenicity to serogroup C, and the pre-specified immunogenicity criteria for serogroups A, W-135 and Y were met. Exploratory analyses suggested that rSBA geometric mean titers (GMTs), hSBA GMTs and proportions of toddlers with rSBA titers ≥ 1:128 and hSBA titers ≥ 1:4 and ≥ 1:8 were higher for all serogroups at one month post-vaccination with MenACWY-TT compared with MenC-CRM 197. At three years post-vaccination, at least 90.8% and 73.6% of MenACWY-TT recipients retained rSBA titers ≥ 1:8 for all serogroups and hSBA titers ≥ 1:4 for serogroups C, W-135 and Y, respectively, but the percentages of toddlers with hSBA titers ≥ 1:4 for serogroup A decreased to 21.8%. In both groups, grade 3 adverse events were infrequently reported and no serious adverse events were considered causally related to vaccination. These results suggest that one single dose of MenACWY-TT induces a robust and persistent immune response and has an acceptable safety profile in toddlers.
authors.affiliation: Vaccine Research Center; University of Tampere, Medical School/FM3; Tampere, Finland. timo.vesikari@uta.fi
authors.forename: Timo
authors.initials: T
authors.lastname: Vesikari
authors.forename: Aino
authors.initials: A
authors.lastname: Forstén
authors.forename: Dominique
authors.initials: D
authors.lastname: Boutriau
authors.forename: Véronique
authors.initials: V
authors.lastname: Bianco
authors.forename: Marie
authors.initials: M
authors.lastname: Van der Wielen
authors.forename: Jacqueline M
authors.initials: JM
authors.lastname: Miller
mesh_terms: D000907:Antibodies, Bacterial / Q000097:blood*; D001770:Blood Bactericidal Activity; D003165:Complement System Proteins / Q000276:immunology; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008585:Meningitis, Meningococcal / Q000517:prevention & control*; D022401:Meningococcal Vaccines / Q000008:administration & dosage / Q000276:immunology*; D013997:Time Factors
chemical_list: D000907:Antibodies, Bacterial; D022401:Meningococcal Vaccines; C576777:tetravalent meningococcal serogroups A, C, W-135 and Y tetanus toxoid conjugate vaccine; D003165:Complement System Proteins