Neisseria meningitidis serogroup A, C, Y, and W-135 capsular polysaccharides (MenACWY polysaccharides)

Neisseria meningitidis serogroups A, C, Y, and W-135 are encapsulated Gram-negative bacteria responsible for life-threatening invasive diseases such as meningitis and septicemia (StatPearls, 2023). The capsular polysaccharides of these serogroups are essential virulence factors that protect the bacteria from host immune defenses by inhibiting phagocytosis (CDC, 2022). In the context of immunization, these polysaccharides serve as the primary antigens in quadrivalent meningococcal vaccines (FDA, 2020). When introduced into the body, typically conjugated to a carrier protein like diphtheria toxoid or CRM197 to enhance immunogenicity and induce T-cell memory, they stimulate the production of specific bactericidal antibodies (StatPearls, 2023). These antibodies recognize the polysaccharide capsule, leading to the destruction of the bacteria through complement-mediated lysis or opsonophagocytosis, thereby preventing invasive disease (FDA, 2020).

Other names

Meningococcal group A, C, Y, and W-135 capsular polysaccharidesQuadrivalent meningococcal polysaccharidesMenACWY antigensMeningococcal polysaccharide vaccine

Induction of serogroup-specific bactericidal antibodies that facilitate complement-mediated lysis and opsonophagocytosis of Neisseria meningitidis (FDA, 2020; StatPearls, 2023).