Neisseria meningitidis Group C capsular polysaccharide (MenC) (MenC)

Neisseria meningitidis Group C capsular polysaccharide is a critical virulence factor and the primary molecular target for vaccines against serogroup C meningococcal disease (CDC, 2022). This target is a homopolymer composed of alpha(2-9)-linked N-acetylneuraminic acid (sialic acid) residues, which can be O-acetylated at the C-7 or C-8 positions (PubChem, CID 446066). Its biological function is to protect the bacterium from the host's immune system by preventing opsonophagocytosis and inhibiting the alternative complement pathway (PubMed, PMID 11516031). In clinical medicine, this polysaccharide is the basis for both plain polysaccharide vaccines and more effective conjugate vaccines, which link the sugar to a carrier protein to induce a T-cell dependent immune response (WHO, 2023). These vaccines are highly effective at preventing invasive diseases such as meningitis and septicemia caused by this specific serogroup (StatPearls, NBK534765). The interaction between the vaccine and the immune system results in the production of protective IgG antibodies that facilitate the bactericidal killing of the pathogen (EMA, Menjugate EPAR).

Other names

MenC antigenGroup C meningococcal polysaccharidealpha(2-9)-linked polysialic acidNeisseria meningitidis serogroup C capsular antigen

Induction of active immunity through the production of capsular-specific bactericidal antibodies that facilitate complement-mediated lysis and opsonophagocytosis of the bacteria.