Meningococcal disease is a major cause of morbidity and mortality worldwide. Its 
epidemiology is currently dominated by five capsular serogroups (A, B, C, W, and 
Y). While effective vaccines already exist for serogroups A, C, W and Y, except 
for under clonal outbreaks, no vaccine was available against serogroup B. 
Recently, a four component vaccine, Bexsero(®), designed to prevent infection 
caused by this serogroup, has been approved in Europe and other Countries for 
use in individuals from two months of age and older. The active components of 
this vaccine are three recombinant proteins identified by reverse vaccinology 
combined with detergent extracted outer membrane vesicles (DOMV) prepared from a 
New Zealand epidemic strain. Considering their intrinsic complexity, we 
performed additional characterization of DOMVs on top of the standard quality 
control testing carried out for batch release. We applied the Hi3 label-free 
LC-MS(E) methodology to qualitatively and quantitatively characterize the DOMV 
protein content. We first, successfully investigated the robustness and the 
accuracy of the methodology for the DOMV characterization and we then applied it 
to compare six DOMV production lots. Around 100 proteins were quantified from 
each preparation. When classified according to their predicted cellular 
localization, about 90% of the total protein amount belongs consistently to the 
outer membrane compartment. Using nonparametric hypothesis testing and 
complementary log-log linear regression, the quantifications of a subset of 21 
proteins common to all lots and including approximately 90% (85-92%) of the 
total protein amount quantified in any DOMV lot were found consistent across 
lots. The relevance of these results is two-fold, showing that the Hi3 
quantification methodology is robust for a broad range of proteins and 
indicating that the manufacturing process currently used for the production of 
the Bexsero(®) DOMV components is highly reproducible and consistent.