Safety and immunogenicity of a new Neisseria meningitidis serogroup C-tetanus toroid conjugate vaccine in healthy adults

We evaluated the safety and immunogenicity of a single dose of a new serogroup C O-deacylated meningococcal polysaccharide-tetanus toroid conjugate vaccine in 30 healthy adult volunteers. The vaccine was well tolerated with no serious adverse events and minimal local reactions and systemic symptoms. All subjects developed a fourfold or greater increase in serum bactericidal antibody (SBA) to serogroup C meningococcus. SEA geometric mean titre increased from 11 to 3649 (p < 0.001). Serogroup C-specific IgG levels increased postvaccination from 0.65 to 17.02 mu g/ml (p < 0.001). Bactericidal titres pre- and postimmunisation showed significant correlation with serogroup C-specific IgG (r(2) = 0.693). Antibody levels fell by 6 months postvaccination, however, meningococcal C IgG avidity increased indicating the successful induction of a T-cell-dependent antibody response. Conclusion: meningococcal C-tetanus toroid conjugate vaccine is immunogenic and well tolerated in healthy adults. (C) 1999 Elsevier Science Ltd. All rights reserved.