Meningococcal groups A, C, W-135, and Y capsular polysaccharides (MenACWY)

The target refers to the capsular polysaccharides of Neisseria meningitidis serogroups A, C, W-135, and Y, which are the essential antigenic components of quadrivalent meningococcal conjugate vaccines (CDC, 2023). These polysaccharides are complex carbohydrates that form the outermost layer of the bacteria, protecting them from the host's immune system and determining the serogroup specificity (WHO, 2023). In vaccine development, these polysaccharides are conjugated to carrier proteins like CRM197 or diphtheria toxoid to overcome the limitations of pure polysaccharide vaccines, which are poorly immunogenic in infants and do not induce immunological memory (Pollard et al., 2009). This conjugation allows for a T-cell dependent immune response, leading to the production of high-affinity bactericidal antibodies and the establishment of long-term protection (FDA, 2020). The primary clinical goal of targeting these polysaccharides is the prevention of invasive meningococcal disease, which can cause severe meningitis and sepsis with high mortality rates (CDC, 2023). Monitoring of vaccine efficacy is typically performed using serum bactericidal assays (SBA) to measure the functional activity of the induced antibodies (WHO, 2023).

Other names

Quadrivalent meningococcal conjugate vaccineMenACWY vaccineMCV4Meningococcal (Groups A, C, Y and W-135) Polysaccharide Diphtheria Toxoid Conjugate Vaccine

Induction of a T-cell dependent immune response through the presentation of polysaccharide-protein conjugates to B and T cells, leading to the production of high-affinity IgG antibodies and immunological memory against Neisseria meningitidis serogroups A, C, W-135, and Y.