The poor immunogenicity of the meningococcal serogroup B (MenB) capsule has led 
to the development of vaccines targeting subcapsular antigens, in particular the 
immunodominant and diverse outer membrane porin, PorA. These vaccines are 
largely strain specific; however, they offer limited protection against the 
diverse MenB-associated diseases observed in many industrialized nations. To 
broaden the scope of its protection, the multicomponent vaccine (4CMenB) 
incorporates a PorA-containing outer membrane vesicle (OMV) alongside relatively 
conserved recombinant protein components, including factor H-binding protein 
(fHbp), Neisseria adhesin A (NadA), and neisserial heparin-binding antigen 
(NHBA). The expression of PorA is unique to meningococci (Neisseria 
meningitidis); however, many subcapsular antigens are shared with nonpathogenic 
members of the genus Neisseria that also inhabit the nasopharynx. These 
organisms may elicit cross-protective immunity against meningococci and/or 
occupy a niche that might otherwise accommodate pathogens. The potential for 
4CMenB responses to impact such species (and vice versa) was investigated by 
determining the genetic distribution of the primary 4CMenB antigens among 
diverse members of the common childhood commensal, Neisseria lactamica. All the 
isolates possessed nhba but were devoid of fhbp and nadA. The nhba alleles were 
mainly distinct from but closely related to those observed among a 
representative panel of invasive MenB isolates from the same broad geographic 
region. We made similar findings for the immunogenic typing antigen, FetA, which 
constitutes a major part of the 4CMenB OMV. Thus, 4CMenB vaccine responses may 
impact or be impacted by nasopharyngeal carriage of commensal neisseriae. This 
highlights an area for further research and surveillance should the vaccine be 
routinely implemented.