Indeed, in a murine nasal challenge model, where GM Streptococcus gordonii expressing meningococcal NadA was used to inoculate mice, colonised subjects produced systemic anti-NadA bactericidal antibodies and localised anti-NadA IgA.26 The nadA gene is associated with hypervirulent strains of N. meningitidis and was present in 50% of strains isolated from cases of meningococcal disease.27 NadA has a role in increased adhesion and invasion into human epithelial cells28 so NadA expression may therefore increase the ability of N. lactamica to colonise the nasopharynx. Here, CD79A is linked to meningococcal infection.