There is a particular need for an effective vaccine against life-threatening meningitis and septicemia caused by Neisseria meningitidis (meningococcus) serogroup B strains. Vaccine strategies incorporating capsular polysaccharide have proved effective against other meningococcal serogroups, but are not applicable to serogroup B. Attention has therefore focused on the subcapsular outer membrane protein antigens as potential vaccine components. The sequencing of genomes from three serogroups and the availability of the corresponding translated protein databases, combined with the development of sensitive proteomic techniques, have opened up new avenues of meningococcal vaccine research. This has resulted in the identification of potential candidate antigens for incorporation into multicomponent meningococcal vaccines.