Neisseria lactamicaProtects against Experimental Meningococcal Infection

ABSTRACTImmunological and epidemiological evidence suggests that the development of natural immunity to meningococcal disease results from colonization of the nasopharynx by commensal Neisseriaspp., particularly with N. lactamica. We report here that immunization with N. lactamicakilled whole cells, outer membrane vesicles, or outer membrane protein (OMP) pools and protected mice against lethal challenge by a number of diverse serogroup B and C meningococcal isolates in a model of bacteremic infection. Sera raised to N. lactamicakilled whole cells, OMPs, or protein pools were found to cross-react with meningococcal isolates of a diverse range of genotypes and phenotypes. The results confirm the potential of N. lactamicato form the basis of a vaccine against meningococcal disease.