An evaluation of the immunogenicity and safety of a new trivalent meningococcal polysaccharide vaccine

The immunogenicity and safety of a meningococcal trivalent A/C/W135 polysaccharide vaccine was compared with that of a tetravalent A/C/Y/W135 polysaccharide vaccine in a randomised, double blind trial. The study included 360 adults, who received either a trivalent or tetravalent polysaccharide meningococcal vaccine. Antibody responses were determined by serum bactericidal antibody (rSBA) assays prior to vaccination and on day 28 and month I I after vaccination. The percentage of participants in the trivalent vaccine group who had rSBA titres >= 8 on day 28 post-vaccination against serogroups A, C and W 135 meningococci were 99, 98 and 91%, respectively. The corresponding figures in the tetravalent vaccine group were 99, 99 and 90%. The percentage of participants with various cut off levels of rSBA against serogroups A, W135 and C meningococci on day 28 and 11-month post-vaccination and the incidence of adverse events did not differ significantly between the two groups. (C) 2007 Elsevier Ltd. All rights reserved.