Neisseria meningitidis serogroup A capsular polysaccharide–CRM197 conjugate (MenA-CRM197)

Neisseria meningitidis serogroup A capsular polysaccharide–CRM197 conjugate is a vaccine antigen designed to provide immunity against invasive meningococcal disease caused by serogroup A bacteria. It consists of the bacterial capsular polysaccharide chemically linked to CRM197, a non-toxic mutant of the diphtheria toxin that serves as a carrier protein (Pichichero, 2013). This conjugation is necessary because pure polysaccharides are T-cell independent antigens that do not elicit a strong immune response or memory in young children (Pollard et al., 2009). By incorporating the CRM197 protein, the vaccine induces a T-cell dependent response, leading to the production of high-affinity bactericidal antibodies and long-lasting B-cell memory (WHO, 2023). This specific conjugate is a primary component of the quadrivalent vaccine Menveo, which protects against serogroups A, C, W-135, and Y (FDA, 2023). The primary clinical endpoint for efficacy is the induction of serum bactericidal activity (SBA), which correlates with protection against meningitis and sepsis (StatPearls, 2023).

Other names

Meningococcal group A conjugateMenA-CRM197MenA-DT mutant conjugateMeningococcal oligosaccharide group A conjugate

Induction of T-cell dependent humoral immunity and immunological memory against Neisseria meningitidis serogroup A.