Development of a Vaccine for Neisseria Meningitidis Group B Based on Native Outer Membrane Vesicles

A novel approach for development of a meningococcal group B vaccine has been developed. This approach , which uses vesicles or blebs of the meningococcal outer membrane prepared without exposure to detergent or denaturing solvents, allows the outer membrane antigens to be presented to the immune system in their natural conformation and membrane environment. Two strategies for using these native outer membrane vesicles (NOMV) as a vaccine have been investigated. The first is intranasal vaccination using NOMV prepared from a capsule negative mutant, and the second is intramuscular vaccination using NOMV prepared from a double mutant that is capsule negative and expresses a mutant lipopolysaccharide with low endotoxin activity. The intranasal vaccine has been evaluated in mice and rabbits and in two phase 1 clinical studies. The intramuscular vaccine has been evaluated in animals and is currently being evaluated in a clinical study. Results obtained to date with these vaccines are promising and show evidence of a high quality and quite cross reactive antibody response.