Meningococcal oligosaccharide diphtheria CRM-197 conjugate combined with meningococcal multicomponent recombinant vaccine+ OMV

Non-inferiority of immune response of two doses of two different formulations of MenABCWY vaccine to a single dose of MenACWY vaccine as measured by the percentage of subjects with hSBA seroresponse against N.meningitidis serogroups A,C,W and Y. Seroresponse is defined as: 1. For subjects with a pre-vaccination hSBA titer \< 1:4, a post-vaccination hSBA titer ≥ 1:8; 2. For subjects with a pre-vaccination hSBA titer ≥ 1:4, an increase in hSBA titer of at least four times the prevaccination titer. Functional bactericidal antibodies directed against serogroups A,C,W,Y meningococci were measured with a serum bactericidal activity assay using human serum as the source of exogenous complement (hSBA).

The overall desirability index (DI) used to identify the optimal formulation of the combination vaccine was based on immunogenicity and reactogenicity parameters (on a scale of 0 to 1, with 0 for an undesirable response and 1 for a highly desirable response) as follows: Between-group ratios of hSBA GMTs were calculated, adjusted for prevaccination titer and center, against serogroups A, C, W, and Y (ABCWY+OMV group or ABCWY+qOMV group vs. Placebo/ACWY group) and against the 4 serogroup B test strains (ABCWY+OMV group or ABCWY+qOMV group vs. rMenB+OMV group). Reactogenicity was measured by the percentage of doses associated with severe local and systemic solicited AEs within 3 days following vaccination. Each immunogenicity and reactogenicity endpoint was assigned its own DI based on predefined desirability functions. The overall DI was calculated using the weighted geometric mean of the DI values of each of the ten parameters to derive an overall DI for each formulation.

Antibody response was measured as the percentage of subjects with human serum bactericidal assay (hSBA) titers ≥1:8 and associated 95% CI, directed against to N meningitidis serogroups A, C, W, and Y at 6 months following first vaccine during the parent study NCT01210885 and one month after third vaccination (Month 7).

Antibody response was measured as the percentage of subjects with human serum bactericidal assay (hSBA) titers ≥1:5 and associated 95% CI, directed against to Serogroup B Test Strains at 6 months following first vaccine during the parent study NCT01210885 and one month after third vaccination (Month 7)