Current status--meningococcal vaccine.

Abstract

The discovery that purified meningococcal capsular polysaccharides are immunogenic in man 1 and can be used as vaccines2 was a major advance, since previous attempts at vaccination against meningococcal disease with whole organisms or autolysates had met with only limited success. The meningococcal vaccines are composed of chemically defined antigens consisting of purified capsftlar polysaccharides derived from bacterial cell wall, each inducing immunity against a specific serogroup. These vaccines serve as a weapon against epidemics ofmeningococcal meningitis which still occurs either sporadically or unpredictably, or in some areas with devastating regularity.3 However in most countries meningococcal infection is uncommon with annual attack rates of around one case per 100,000 population, most cases occurring among the very young, the group in which vaccines are least effective. Following the Delhi epidemic in 1985, interest in meningococcal disease and its prevention has resurged in India amongst clinicians, immunologists and even the lay population.