The tetravalent meningococcal serogroups A, C, W-135, and Y tetanus toxoid conjugate vaccine is immunogenic with a clinically acceptable safety profile in subjects previously vaccinated with a tetravalent polysaccharide vaccine

SummaryObjectivesThe immunogenicity and safety of the tetravalent meningococcal serogroups A, C, W-135, and Y tetanus toxoid conjugate vaccine (MenACWY–TT) were evaluated in subjects previously vaccinated with a tetravalent meningococcal polysaccharide vaccine and in subjects without previous meningococcal vaccination.MethodsIn this phase II, open, controlled study (NCT00661557), healthy subjects aged 4.5–34 years received one dose of MenACWY–TT at month 0. Subjects in the MPS group (n = 192) had received polysaccharide vaccine in a study conducted 30–42 months earlier; age-matched subjects in the noMPS control group (n = 79) had received no meningococcal vaccination within the past 10 years. Serum bactericidal activity using rabbit complement (rSBA) was measured at month 0 and month 1.ResultsAt month 1, ≥97.0% of subjects had rSBA titers ≥1:128. Post-vaccination rSBA geometric mean titers (GMTs) were ≥3.9-fold higher than pre-vaccination in both treatment groups. Exploratory analyses showed no statistically significant differences between groups in percentages of subjects with rSBA titers ≥1:8 and ≥1:128, but significantly lower rSBA GMTs and vaccine response rates for each serogroup in the MPS versus the noMPS group. MenACWY–TT had an acceptable safety profile in both groups.ConclusionsThese results suggest that MenACWY–TT could be used in vaccination programs irrespective of the pre-vaccination status with polysaccharide vaccine.