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Publications (8)33.78 Total impact

  • Article: Safety, immunogenicity, and immune memory of a novel meningococcal (groups A, C, Y, and W-135) polysaccharide diphtheria toxoid conjugate vaccine (MCV-4) in healthy adolescents.
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    ABSTRACT: A meningococcal (groups A, C, Y, and W-135) polysaccharide diphtheria toxoid conjugate vaccine (MCV-4; Menactra; Sanofi Pasteur Inc, Swiftwater, Pa) was developed to improve the profile of currently licensed products. The objective of this study was to compare the tolerability, immunogenicity, and immune memory of MCV-4 with those of a quadrivalent polysaccharide vaccine (PSV-4; Menomune A/C/Y/W-135; Sanofi Pasteur Inc). A randomized, double-blind trial was performed at 11 clinical centers in the United States. The vaccine MCV-4 or PSV-4 was administered to 881 healthy 11- to 18-year-olds. Sera were collected prevaccination and 28 days postvaccination. Three-year follow-up and booster vaccination with MCV-4 were performed in a participant subset from each group and a control group. Proportion of participants with a 4-fold or greater increase in serum bactericidal antibody against each serogroup 28 days after initial vaccination, geometric mean serum bactericidal antibody titers, and safety assessments. Both vaccines were well tolerated; most reactions were mild. More MCV-4 recipients reported solicited local reactions (68.9%) than PSV-4 recipients (30.2%). Both MCV-4 and PSV-4 were highly immunogenic; similar proportions of participants had 4-fold or greater increases in serum bactericidal antibody (range, 80.1%-96.7%) to the 4 serogroups. Three-year follow-up showed persistence of serum bactericidal antibody and booster responses to MCV-4 consistent with immune memory in participants previously vaccinated with MCV-4, but not in those who had previously received PSV-4. The vaccine MCV-4 was well tolerated and highly immunogenic. Persistence of bactericidal activity with MCV-4, but not PSV-4, was evident 3 years after the initial immunization. Booster response was demonstrated after a second vaccination with MCV-4.
    Archives of Pediatrics and Adolescent Medicine 11/2005; 159(10):907-13. · 4.14 Impact Factor
  • Article: Comparative trial of the safety and immunogenicity of quadrivalent (A, C, Y, W-135) meningococcal polysaccharide-diphtheria conjugate vaccine versus quadrivalent polysaccharide vaccine in two- to ten-year-old children.
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    ABSTRACT: 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). 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. 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. 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.
    The Pediatric Infectious Disease Journal 02/2005; 24(1):57-62. · 3.58 Impact Factor
  • Article: Dosage escalation, safety and immunogenicity study of four dosages of a tetravalent meninogococcal polysaccharide diphtheria toxoid conjugate vaccine in infants.
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    ABSTRACT: Young children have the highest incidence of meningococcal infection. Approximately 50% of disease in United States children less than 2 years of age is caused by serogroups C and Y. In the developing world, serogroups A and W-135 cause outbreaks and epidemics of infection. Three groups of 30 infants were enrolled. The first group of infants was given 3 doses of a quadrivalent (group A, C, Y, W-135) polysaccharide meningococcal vaccine conjugated to diphtheria toxoid (MCV-4) at a dosage of 1 microg of each serogroup polysaccharide. The second group of infants was given MCV-4 at a dosage of 4 microg, and the last group of children received a 10-microg dosage. Vaccinations were given at 2, 4 and 6 months of age.A subset of these children was vaccinated at 15 to 18 months of age with licensed meningococcal polysaccharide (A, C, Y, W-135) vaccine. Serum bactericidal antibody (SBA) titers were measured with baby rabbit complement. The proportion of infants with local reactions increased significantly with increasing dosages after Injection 1 and 3. Approximately 1 month after completion of the primary series, the proportion of infants with an SBA titer > or = 1/8 ranged from 54 to 92%, depending on the serogroup and dose of polysaccharide contained in the vaccine. The SBA geometric mean titer varied from 17.4 to 101.6. There was no statistically significant difference between the SBA responses among the 3 dosage groups. After vaccination with polysaccharide vaccine at 15 to 18 months of age, mean fold increases in SBA of 4.9 to 170.3 were observed, suggesting an anamnestic response. MCV-4 appears to have a reactogenicity profile acceptable to parents and health care providers. It was only modestly immunogenic in infants, but it appeared to prime the immune system of the majority of infants given three doses in infancy. There is no statistically significant immunologic advantage conferred by increasing the dosage beyond 4 microg/ml, and local reactions are more frequent after the 10-microg/ml dosage.
    The Pediatric Infectious Disease Journal 06/2004; 23(5):429-35. · 3.58 Impact Factor
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    Article: Assignment of Neisseria meningitidis serogroups A, C, W135, and Y anticapsular total immunoglobulin G (IgG), IgG1, and IgG2 concentrations to reference sera.
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    ABSTRACT: 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.
    Clinical and Diagnostic Laboratory Immunology 02/2004; 11(1):1-5. · 2.51 Impact Factor
  • Article: Immunogenicity and immunological priming of the serogroup a portion of a bivalent meningococcal A/C conjugate vaccine in 2-year-old children.
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    ABSTRACT: 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.
    The Journal of Infectious Diseases 05/2003; 187(7):1142-6. · 6.41 Impact Factor
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    Article: Safety, reactogenicity, and immunogenicity of a tetravalent meningococcal polysaccharide-diphtheria toxoid conjugate vaccine given to healthy adults.
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    ABSTRACT: Healthy adults, 18-55 years old, were immunized once with a tetravalent (serogroups A, C, Y, and W-135) meningococcal vaccine conjugated to diphtheria toxoid at 1 of 3 doses and were monitored for safety, reactogenicity, and immunogenicity. No immediate reactions were observed. Only 1 of 89 subjects reported fever; only 1 reported any severe reactogenicity (local pain/soreness, chills, arthralgia, anorexia, and malaise). For each serogroup and in each dose group, the geometric mean serum bactericidal antibody (SBA) titer and immunoglobulin G concentration increased after immunization. In the 4- and 10-microg-dose groups, all subjects had SBA titers >/=8 against serogroups A and C, and 89% and 93% of subjects had SBA titers >/=8 against serogroups Y and W-135, respectively. The A, C, Y, and W-135 Neisseria meningitidis-diphtheria toxoid conjugate vaccine, when given to healthy adults as a single intramuscular injection of 1, 4, or 10 microg/serogroup, is acceptably tolerated and immunogenic and deserves further development.
    The Journal of Infectious Diseases 12/2002; 186(12):1848-51. · 6.41 Impact Factor
  • Article: Dose escalation, safety and immunogenicity study of a tetravalent meninogococcal polysaccharide diphtheria conjugate vaccine in toddlers.
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    ABSTRACT: Two injections of tetravalent (Groups A, C, Y and W-135) meningococcal polysaccharide vaccine conjugated to diphtheria were given to 30 toddlers at dosages of 1, 4 and 10 microg/ml polysaccharide of each serogroup. Reactogenicity was acceptable at all dosages. The 4-microg/ml dose appears to be immunologically optimal.
    The Pediatric Infectious Disease Journal 11/2002; 21(10):978-9. · 3.58 Impact Factor
  • Article: Safety and immunogenicity of a meningococcal (Groups A, C, Y, W-135) polysaccharide diphtheria toxoid conjugate vaccine in healthy children aged 2 to 10 years in Chile.
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    ABSTRACT: Immune responses to meningococcal conjugate (Menactra; MCV-4) and plain polysaccharide (Menomune-A/C/Y/W-135; PSV-4) vaccines against serogroups A, C, Y, and W-135 were assessed in 220 of 1037 Chilean children aged 2 to 10 years participating in a comparative safety trial. Both vaccines were generally well tolerated. Geometric mean serum bactericidal antibody (SBA) titers 28 days postvaccination were comparable in both groups for all four serogroups. Seroconversion was evident in > 97% of MCV-4 and > 90% of PSV-4 vaccinees who tested seronegative at baseline. Menactra safely induced broad and robust immune responses against serogroups A, C, Y and W-135 in this population.
    Human vaccines 1(6):228-31. · 3.58 Impact Factor