Impact of MenBvac, an outer membrane vesicle (OMV) vaccine, on the meningococcal carriage.

The aim of the study was to analyze the impact of MenBvac, an outer membrane vesicle (OMV) vaccine against P1.7,16 strains, on meningococcal carriage. During a B:14:P1.7,16/ST-32 outbreak in Normandy (France), children aged 1-7 years were randomly selected to participate in the study. Among the 1082 volunteers, there were 17 Neisseria meningitidis carriers (carriage rate of 1.57%). MenBvac vaccination appeared associated with lower carriage rate, i.e., 0.31% among the vaccinated children versus 2.10% among the non-vaccinated (p=0.03). The beneficial effect on carriage was observed regardless of the strain serogroup. OMV-vaccinated mice also showed reduction of bacterial acquisition of OMV-homolog and hererolog strains in respiratory pathways after intranasal challenge. These results suggest that meningococcal OMV-based vaccines reduce meningococcal carriage and may hence confer herd immunity.