(American Society for Microbiology) -- A harmless bacteria can elicit an immune response that protects against a common cause of bacterial meningitis and could serve as a potential vaccine against the disease, say researchers from the United Kingdom. Their findings appear in the July 2002 issue of the journal Infection and Immunity.

Neisseria lactamica is a bacterium that does not cause human disease, but closely resembles Neisseria meningitidis, one of the causes of bacteria meningitis. Previous studies have suggested that the development of natural immunity to menigococcal disease results from colonization of the nasal cavities by harmless Neisseria bacteria, particularly N. lactamica.

"The present study explores experimentally the hypothesis that immunization with N. lactamica can mimic infection by and enhance natural immunity to the meningococcus," say the researchers. In the study mice that were immunized with killed N. lactamica bacteria were protected from lethal infection by a number of strains of menigococcal bacteria. "The results confirm the potential of N. lactamica to form the basis of a vaccine against meningococcal disease."