title: Antibody persistence and immune memory 15 months after priming with an investigational tetravalent meningococcal tetanus toxoid conjugate vaccine (MenACWY-TT) in toddlers and young children.
abstract: The present extension study, conducted in children originally vaccinated at 12-14 mo or 3-5 y of age, assessed antibody persistence and immune memory induced by an investigational tetravalent meningococcal serogroups A, C, W-135 and Y tetanus toxoid conjugate vaccine (MenACWY-TT). In the original study, participants were randomized to receive one dose of MenACWY-TT or licensed age-appropriate meningococcal control vaccines. Fifteen months post-vaccination, all participants underwent serum sampling to evaluate antibody persistence and participants previously vaccinated as toddlers received a polysaccharide challenge to assess immune memory development. Exploratory comparisons showed that (1) All children and ≥ 92.3% of the toddlers maintained serum bactericidal (rSBA) titers ≥ 1:8 at 15 mo post MenACWY-TT vaccination; statistically significantly higher rSBA geometric mean titers (GMTs) were observed compared with control vaccines. (2) At one month after polysaccharide challenge, all toddlers primed with MenACWY-TT or with the monovalent serogroup C conjugate vaccine had rSBA titers ≥ 1:8 and ≥ 1:128 for serogroup C and similar rSBA-GMTs; rSBA-GMTs for serogroups A, W-135 and Y were statistically significantly higher in toddlers primed with MenACWY-TT compared with the control vaccine. Thus, a single dose of MenACWY-TT induced persisting antibodies in toddlers and children and immune memory in toddlers. This study has been registered at www.clinicaltrials.gov NCT00126984.
authors.affiliation: Zentrum für Kinder-und Jugendmedizin, Johannes Gutenberg-University, Mainz, Germany.
authors.forename: Markus
authors.initials: M
authors.lastname: Knuf
authors.forename: Yaela
authors.initials: Y
authors.lastname: Baine
authors.forename: Veronique
authors.initials: V
authors.lastname: Bianco
authors.forename: Dominique
authors.initials: D
authors.lastname: Boutriau
authors.forename: Jacqueline M
authors.initials: JM
authors.lastname: Miller
mesh_terms: D000907:Antibodies, Bacterial / Q000097:blood*; D001770:Blood Bactericidal Activity; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007156:Immunologic Memory; D007223:Infant; D008297:Male; D022401:Meningococcal Vaccines / Q000008:administration & dosage* / Q000276:immunology*; D050296:Microbial Viability; D009345:Neisseria meningitidis / Q000276:immunology / Q000502:physiology
chemical_list: D000907:Antibodies, Bacterial; D022401:Meningococcal Vaccines; C576777:tetravalent meningococcal serogroups A, C, W-135 and Y tetanus toxoid conjugate vaccine