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.