[Meningococcal vaccines: present status and perspectives].

Neisseria meningitidis can cause asymptomatic carriage, followed by acquired immunity, or septicaemia, meningitis, septic arthritis or pericarditis. Vaccination induces protective bactericidal antibodies to invasive diseases. Meningococcal capsular polysaccharides are immunoprotective antigens from which vaccines are produced against serogroups A, C, Y and W135, including conjugate vaccines against serogroup C. There is no available vaccine against serogroup B, but outermembrane protein-based vaccines against this serogroup are currently being evaluated. Polysaccharide meningococcal vaccines are effective, but their strictly serogroup-specific efficacy raises concerns about the possible selection of escape variants. Therefore, meningococcal polysaccharide vaccines, either plain or conjugated, are indicated against the clonal expansion of strains whose serogroup has been properly identified and corresponds to the vaccine valence.