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

Objectives: The 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. Methods: In 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. Results: At 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. Conclusions: These results suggest that MenACWY-TT could be used in vaccination programs irrespective of the pre-vaccination status with polysaccharide vaccine. (C) 2012 International Society for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.