Neisseria meningitidis capsular polysaccharide (CPS) (CPS)

Neisseria meningitidis capsular polysaccharides are complex carbohydrate structures that form the outermost protective layer of the meningococcus bacterium (Stephens et al., 2007, The Lancet). These polysaccharides are critical virulence factors that enable the pathogen to survive in the host bloodstream by resisting immune mechanisms such as phagocytosis and complement-mediated killing (Harrison et al., 2009, Vaccine). There are several clinically significant serogroups—A, B, C, W, and Y—defined by the specific chemical composition of these polysaccharides (CDC, 2023, Meningococcal Vaccination). In vaccine development, these polysaccharides serve as the primary antigens to induce protective immunity. While plain polysaccharide vaccines are effective in adults, they are often conjugated to carrier proteins to enhance immunogenicity and induce T-cell dependent memory in infants and young children (Pollard et al., 2009, Nature Reviews Immunology). Notably, the serogroup B polysaccharide is generally excluded from these vaccines due to its structural similarity to human neural cell adhesion molecules, which results in poor immunogenicity and potential safety concerns (Finne et al., 1983, The Lancet).

Other names

Meningococcal capsular polysaccharideMenCPSBacterial capsular polysaccharideMeningococcal antigen

Induction of serogroup-specific bactericidal antibodies that facilitate opsonophagocytosis and complement-mediated lysis of the bacteria (Pollard et al., 2009, Nature Reviews Immunology).