Antibody Persistence and Response to a Booster Dose of a Quadrivalent Conjugate Vaccine for Meningococcal Disease in Adolescents
ABSTRACT BACKGROUND:: In a previous randomized phase 2 study in adolescents, a CRM197 meningococcal conjugate vaccine against serogroups A, C, W-135, and Y (MenACWY-CRM) was well tolerated and immunogenic, compared with a plain polysaccharide vaccine (MenACWY-PS). METHODS:: This extension study assessed antibody persistence 5 years after primary vaccination with MenACWY-CRM (n=50) or MenACWY-PS (n=51), and the immunogenicity and reactogenicity of a dose of MenACWY-CRM given 5 years after primary vaccination; antibody response was also compared with vaccine-naive controls (n=54). The primary endpoints were the percentage of subjects with titers ≥8 by serum bactericidal activity assay using human complement (hSBA) 5 years after primary vaccination, and hSBA geometric mean titers 1 month after the MenACWY-CRM dose given in the current study. RESULTS:: Five years after primary vaccination, over 70% of subjects who had received MenACWY-CRM were seropositive (hSBA titers ≥8) for serogroups C, W-135, and Y; for serogroups C and Y, the percentages of seropositive subjects were significantly higher in subjects previously vaccinated with MenACWY-CRM than in subjects previously vaccinated with MenACWY-PS. The MenACWY-CRM dose given 5 years post primary vaccination elicited an anamnestic response across serogroups in those previously vaccinated with MenACWY-CRM. Responses in those previously vaccinated with MenACWY-PS were less robust but adequate and similar to that seen in the vaccine-naive group, both in magnitude and kinetics. MenACWY-CRM was well tolerated in all three groups. CONCLUSION:: MenACWY-CRM provided a broad and persistent immune response in adolescents. A subsequent dose of MenACWY-CRM elicited an adequate antibody response, regardless of vaccine history.
- [Show abstract] [Hide abstract]
ABSTRACT: Since the introduction of the first meningococcal conjugate vaccines in 1999, remarkable progress has been made in reducing the morbidity and mortality caused by meningococcal disease. Currently, varying meningococcal conjugate vaccines provide protection against serogroups A, C, Y, and W meningococcal disease. A large impact has been seen after vaccine introduction, particularly in the UK after vaccinating all 1-17 year olds. The introduction of serogroup A conjugate vaccine in the meningitis belt has the potential to control epidemics of disease that disproportionately affect this area of the world. Issues remain that require continued vigilance with disease surveillance and frequent reassessment of vaccine strategies. These issues include duration of protection, potential increases in non-vaccine serogroups, and vaccine safety and potential interference with other routine vaccines. Serogroup B meningococcal vaccines are protein-based vaccines, with the first approved in early 2013. Understanding the potential impact of serogroup B vaccines is critical to developing future meningococcal vaccination strategies.Drugs 07/2013; DOI:10.1007/s40265-013-0079-2 · 4.13 Impact Factor
- [Show abstract] [Hide abstract]
ABSTRACT: Serogroup C meningococcal (MenC) disease accounts for one-third of all meningococcal cases and causes meningococcal outbreaks in the U.S. Quadrivalent meningococcal vaccine conjugated to diphtheria toxoid (MenACYWD) was recommended in 2005 for adolescents and high risk groups such as military recruits. We evaluated anti-MenC antibody persistence in U.S. military personnel vaccinated with either MenACYWD or meningococcal polysaccharide vaccine (MPSV4). Twelve hundred subjects vaccinated with MenACYWD from 2006 to 2008 or MPSV4 from 2002 to 2004 were randomly selected from the Defense Medical Surveillance System. Baseline serologic responses to MenC were assessed in all subjects; 100 subjects per vaccine group were tested during one of the following six post-vaccination time-points: 5-7, 11-13, 17-19, 23-25, 29-31, or 35-37 months. Anti-MenC geometric mean titers (GMT) were measured by rabbit complement serum bactericidal assay (rSBA) and geometric mean concentrations (GMC) by enzyme-linked immunosorbent assay (ELISA). Continuous variables were compared using the Wilcoxon rank sum test and the proportion of subjects with an rSBA titer ≥8 by chi-square. Pre-vaccination rSBA GMT was <8 for the MenACWYD group. rSBA GMT increased to 703 at 5-7 months post-vaccination and decreased by 94% to 43 at 3 years post-vaccination. GMT was significantly lower in the MenACWYD group at 5-7 months post-vaccination compared to the MPSV4 group. The percentage of MenACWYD recipients achieving an rSBA titer of ≥8 decreased from 87% at 5-7 months to 54% at 3 years. There were no significant differences between vaccine groups in the proportion of subjects with a titer of ≥8 at any time-point. GMC for the MenACWYD group was 0.14μg/mL at baseline, 1.07μg/mL at 5-7 months, and 0.66μg/mL at 3 years, and significantly lower than the MPSV4 group at all time-points. Anti-MenC responses wane following vaccination with MenACYWD; a booster dose is needed to maintain protective levels of circulating antibody.Vaccine 05/2014; 32(30). DOI:10.1016/j.vaccine.2014.05.001 · 3.49 Impact Factor
- [Show abstract] [Hide abstract]
ABSTRACT: Background: The aim of this study was to evaluate antibody persistence 5 years after primary vaccination with the quadrivalent meningococcal conjugate vaccines MenACWY-CRM or MenACWY-D and 2 years after a booster dose of MenACWY-CRM, in the context of a phase 3 study. Methods: Subjects (aged 19.2 +/- 2.3 years) were assigned to 5 groups according to whether they had previously received primary vaccination (at 14.2 +/- 2.2 years) with MenACWY-CRM (N = 131) or MenACWY-D (N = 76), a booster dose of MenACWY-CRM 3 years after primary vaccination with MenACWY-CRM (N = 44) or MenACWY-D (N = 31) or no vaccination (N = 107). The immunogenicity measures were percentages of subjects with serum bactericidal activity (hSBA) = 1: 8 for serogroups A, C, W and Y and hSBA geometric mean titers. Comparisons with age-matched, vaccine-naive subjects were performed. Results: A majority of subjects vaccinated 5 years previously maintained hSBA = 1:8 against serogroups C, W and Y in the MenACWY-CRM (59%-82%) and MenACWY-D groups (54%-73%); this was lower for serogroup A in both groups. There was a decline in antibody titers after primary vaccination, especially in the first 2 years postprimary vaccination, with steady concentrations during the next 3 years. Two years after MenACWY-CRM booster vaccination the percentages of subjects with hSBA = 1:8 ranged from 77% to 100% across serogroups and geometric mean titers were 2.5 to 8-fold higher than prebooster values across serogroups. Conclusions: Booster vaccination with MenACWY-CRM elicited a robust immune response during the 2-year follow-up period, irrespective of previous vaccination.The Pediatric Infectious Disease Journal 06/2014; 33(11). DOI:10.1097/INF.0000000000000438 · 3.14 Impact Factor