Capsular polysaccharide of Neisseria meningitidis serogroup C (MenC CPS)

The capsular polysaccharide of Neisseria meningitidis serogroup C is a critical virulence factor that defines the serogroup and serves as the primary target for preventive immunization. Structurally, it is a homopolymer of α(2→9)-linked N-acetylneuraminic acid (sialic acid), which may be O-acetylated at the C-7 or C-8 positions [Source: CDC, Pink Book, 2021]. This capsule acts as a protective barrier, allowing the bacterium to evade host innate immune responses such as complement-mediated lysis and phagocytosis by neutrophils [Source: StatPearls, Meningococcal Meningitis, 2023]. In clinical practice, this polysaccharide is used as the antigenic component in both plain polysaccharide and conjugate vaccines. Conjugate vaccines link the polysaccharide to a carrier protein (e.g., CRM197 or tetanus toxoid) to induce a T-cell dependent immune response, which provides superior immunogenicity and long-term memory compared to plain polysaccharide versions [Source: WHO, Meningococcal Vaccines Position Paper, 2011]. These vaccines have been highly effective in reducing the global incidence of invasive meningococcal disease, including meningitis and septicemia, caused by serogroup C [Source: PubMed, PMID: 22137331].

Other names

Neisseria meningitidis serogroup C capsular polysaccharideMenC polysaccharideGroup C meningococcal polysaccharideα(2→9)-linked sialic acid polymer

Induction of protective, serogroup-specific serum bactericidal antibodies (SBA) that facilitate complement-mediated lysis and opsonophagocytosis of Neisseria meningitidis serogroup C.