RESUMO
BACKGROUND: A quadrivalent meningococcal diphtheria conjugate vaccine (MCV-4) has been developed to provide T-cell dependent immune responses against 4 major disease-causing serogroups (A, C, Y, W-135). METHODS: In a comparative, randomized, modified double blind, controlled study in healthy 2- to 10-year-old U.S. children, safety and immunogenicity profiles of MCV-4 (n = 696) were compared with those of a licensed quadrivalent polysaccharide vaccine, Menomune A/C/Y/W-135 (PSV-4, n = 702). Vaccine-related adverse reactions were assessed for 28-day and 6-month follow-up periods. Serum bactericidal activity (SBA) was assayed in prevaccination, day 28 and 6-month postvaccination sera samples. RESULTS: Both vaccines were well-tolerated, with no vaccine-related serious adverse events and similar rates of mostly mild local and systemic reactions. Functional antibody (SBA) seroconversion percentages were significantly higher for all 4 serogroups in the MCV-4 group. The SBA geometric mean titers against serogroups A, C, Y and W-135 with MCV-4 were 1700, 354, 637 and 750, respectively, compared with PSV-4 (893, 231, 408 and 426) 28 days postvaccination (P < 0.001 for all comparisons). This significant difference persisted through 6 months. CONCLUSIONS: In 2- to 10-year-old children MCV-4 had a safety profile similar to that of PSV-4 and elicited significantly higher and more persistent serum bactericidal antibody responses against meningococcal serogroups A, C, Y and W-135 than did the licensed polysaccharide vaccine.
Assuntos
Anticorpos Antibacterianos/sangue , Infecções Meningocócicas/prevenção & controle , Vacinas Meningocócicas/efeitos adversos , Vacinas Meningocócicas/imunologia , Neisseria meningitidis/imunologia , Vacinas Conjugadas/efeitos adversos , Vacinas Conjugadas/imunologia , Criança , Pré-Escolar , Toxoide Diftérico/imunologia , Método Duplo-Cego , Humanos , Vacinas Meningocócicas/administração & dosagem , Neisseria meningitidis/classificação , Polissacarídeos Bacterianos/imunologia , Sorotipagem , Vacinas Conjugadas/administração & dosagemRESUMO
Meningococcal serogroup-specific immunoglobulin G (IgG), IgG1, and IgG2 concentrations were assigned to three reference sera, CDC 1992, 89-SF, and 96/562, for meningococcal serogroups A, C, Y, and W135 via the method of cross standardization. The sum of the serogroup-specific IgG1 and IgG2 concentrations determined for the four meningococcal serogroups showed good agreement with the serogroup-specific IgG either determined here or as previously represented. Following the assignment of meningococcal serogroup-specific IgG1 and IgG2 concentration to these reference sera, a meningococcal serogroup-specific IgG1 and IgG2 enzyme-linked immunosorbent assay protocol was developed. The serogroup A and C specific subclass distribution of a panel of adult sera collected following vaccination with any combination of meningococcal serogroup C conjugate, bivalent, or tetravalent polysaccharide vaccines was determined. For the determination of serogroup W135 and Y specific subclass distribution, an adolescent panel 28 days following a single dose of either tetravalent polysaccharide or conjugate vaccine was used. The sum of the serogroup-specific IgG1 and IgG2 showed strong correlation with the serogroup-specific total IgG determined. The assignment here of IgG1 and IgG2 subclasses to these reference sera will allow more detailed evaluation of meningococcal conjugate and polysaccharide vaccines.
Assuntos
Anticorpos Antibacterianos/sangue , Neisseria meningitidis/classificação , Neisseria meningitidis/imunologia , Adolescente , Adulto , Ensaio de Imunoadsorção Enzimática/normas , Humanos , Imunoglobulina G/sangue , Infecções Meningocócicas/imunologia , Infecções Meningocócicas/microbiologia , Infecções Meningocócicas/prevenção & controle , Vacinas Meningocócicas/imunologia , Neisseria meningitidis Sorogrupo A/classificação , Neisseria meningitidis Sorogrupo A/imunologia , Neisseria meningitidis Sorogrupo C/classificação , Neisseria meningitidis Sorogrupo C/imunologia , Neisseria meningitidis Sorogrupo W-135/classificação , Neisseria meningitidis Sorogrupo W-135/imunologia , Neisseria meningitidis Sorogrupo Y/classificação , Neisseria meningitidis Sorogrupo Y/imunologia , Padrões de Referência , SorotipagemRESUMO
Two-year-old children were vaccinated with 1 dose of meningococcal A/C conjugate (MACC) or meningococcal A/C polysaccharide (MACP) vaccine. Meningococcal serogroup A (MenA)-specific IgG geometric mean avidity indices (GMAIs) increased 1 month after vaccination with MACC (GMAI, 210; 95% confidence interval [CI], 140-300) and MACP (GMAI, 190; 95% CI, 120-310). One year after vaccination, the GMAI of the MACP-vaccinated cohort decreased to 130 (95%, CI 100-170), but a constant GMAI was maintained in the MACC-vaccinated cohort (210; 95% CI, 140-300), despite declining MenA-specific IgG antibody levels.