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Background: We assessed immunogenicity, antibody persistence and safety of the meningococcal serogroups A, C, W and Y-tetanus toxoid (TT) conjugate vaccine (MenACWY-TT) in children primed as toddlers with MenC vaccine., Methods: This open, multicenter extension study enrolled children 84-95 months of age who had received one dose of the combined Haemophilus influenzae type b (Hib)-MenC-TT conjugate vaccine (HibMenC group) or Hib-TT and monovalent MenC (MCC)-CRM197 vaccines (Hib+MCC group) at 12-18 months of age, in the primary study. All participants received one dose of MenACWY-TT. We assessed immunogenicity against MenA, MenC, MenW and MenY at 1 month and 2 years postvaccination by serum bactericidal assay using baby rabbit complement (rSBA). Safety and reactogenicity were evaluated., Results: Six years post-MenC vaccination, <20% of children retained rSBA-MenC titers ≥1:8. At 1 month post-MenACWY-TT vaccination, vaccine response rates against all serogroups were high for both groups with ≥97.1% of children having rSBA ≥1:8. Two years postvaccination, ≥63.6% of children retained rSBA-MenA ≥1:8, and ≥87.9% for other serogroups. Geometric mean titers for all serogroups declined at 2 years post-MenACWY-TT vaccination, but remained ≥13 times higher than prevaccination levels. For both groups, pain (≤58.5%), redness (≤51.4%) and fatigue (≤27.0%) were the most frequently reported adverse events. No serious adverse events were reported., Conclusions: One dose of MenACWY-TT boosts protection against MenC in primed children, is safe and extends protection against MenA, MenW and MenY. Immunogenicity and safety were comparable in infants vaccinated with conjugated vaccine (HibMenC-TT) or the separate vaccines (Hib-TT and MCC-CRM197).

Background: We evaluated the impact of the new pneumococcal Haemophilus influenzae protein D conjugate vaccine (PHiD-CV10, GSK Vaccines) on tympanostomy tube placements (TTPs)., Methods: Finnish Invasive Pneumococcal disease vaccine trial was a nationwide phase III/IV cluster-randomized, double-blind trial. Children younger than 19 months received PHiD-CV10 in two thirds of clusters (N = 52) or hepatitis B or A vaccine as control in 26 clusters according to 3 + 1 or 2 + 1 schedules (infants younger than 7 months) or catch-up schedules. A secondary objective of the trial was to assess vaccine effectiveness (VE) against TTPs in children who received at least one vaccine dose before or after 7 months of age. Blinded follow-up lasted from the date of first vaccination (from February 2009 through October 2010) to December 31, 2011. Outcome data were collected through the National Care register and Social Insurance Institution reimbursement register., Results: More than 47,000 children were enrolled. In 30,527 infants younger than 7 months of age at enrolment, 4369 TTPs were reported in 3594 subjects. The incidence was 7.9 per 100 person-years in the infant control cohort. The VE estimate was 13% [95% confidence interval (CI): -2% to 26%] for combined PHiD-CV10 3 + 1 and 2 + 1 infant schedules. The VE estimates for the 3 + 1 and 2 + 1 infant schedules when estimated separately were similar. For the catch-up schedules, the VE was 11% (95% CI: -7% to 26%) for children enrolled at 7-11 months of age and -1% (95% CI: -21% to 16%) for children enrolled at 12-18 months of age., Conclusions: Our study results suggest that PHiD-CV10 immunization according to a 3 + 1 or 2 + 1 schedule initiated before 12 months of age may reduce the frequency of TTPs, although the primary analysis did not reach statistical significance.

Background: Immunogenicity of 10-valent pneumococcal nontypeable Haemophilus influenzae protein d conjugate vaccine (PHiD-CV), administered as 2-dose or 3-dose priming followed by a booster dose, has been described previously. The present study evaluated immunologic memory following PHiD-CV vaccination according to these vaccination schedules., Methods: A dose of PHiD-CV (to test anamnestic responses) was administered to 172 children at 36 to 46 months of age; 110 of them had previously been vaccinated with PHiD-CV according to 2 + 1 or 3 + 1 schedules (PHiD-CV [2 + 1] and PHiD-CV [3 + 1] groups) and 62 were unprimed age-matched controls. To measure immune responses before and 7 to 10 days after the PHiD-CV dose, 22F-inhibition enzyme-linked immunosorbent assay and opsonophagocytic activity (OPA) assay were used., Results: Serotype-specific IgG geometric mean concentrations (GMCs) and OPA geometric mean titers increased substantially (from before to 7 to 10 days after the additional PHiD-CV dose) for all 10 vaccines and 2 cross-reactive serotypes (6A and 19A) in the children previously vaccinated with PHiD-CV, regardless of the vaccination schedule used. Antibody GMCs and OPA geometric mean titers after the administration of the PHiD-CV dose were markedly higher in both previously PHiD-CV-vaccinated groups than in the unprimed control group, clearly demonstrating prior induction of immunologic memory. Antiprotein D antibody GMCs had also increased substantially from before to 7 to 10 days after vaccination in all 3 groups, with higher antibody GMCs in the previously vaccinated groups than in the control group., Conclusion: PHiD-CV vaccination according to 2 + 1 or 3 + 1 schedules resulted in comparable anamnestic immune responses. These findings suggest that similar protective efficacy may be achieved with both the schedules.