Neisseria meningitidis capsular polysaccharides conjugated to CRM197 carrier protein (MenACWY-CRM)

Neisseria meningitidis capsular polysaccharides conjugated to CRM197 carrier protein is a specialized glycoconjugate used as the active immunogenic component in meningococcal vaccines. This target consists of purified capsular polysaccharides from various serogroups of Neisseria meningitidis—most commonly A, C, Y, and W-135—that are chemically linked to CRM197, a non-toxic mutant of the diphtheria toxin [1, 2]. The primary biological function of this conjugate is to convert the T-cell independent polysaccharide antigens into T-cell dependent antigens, which is necessary to induce a robust immune response in infants and young children [3]. Upon administration, the complex is internalized by B cells and antigen-presenting cells, leading to the presentation of carrier-derived peptides to T-helper cells [4]. This process triggers the production of high-affinity bactericidal IgG antibodies and the formation of long-lasting memory B cells [1]. These antibodies protect the host by promoting complement-mediated lysis and opsonophagocytosis of the meningococci, thereby preventing invasive diseases such as meningitis and septicemia [3]. This conjugate technology has significantly improved the efficacy and duration of protection compared to older, unconjugated polysaccharide vaccines [2].

Other names

Meningococcal oligosaccharide conjugate vaccineMenACWY-CRMCRM197-conjugated meningococcal polysaccharidesQuadrivalent meningococcal conjugate vaccine

The target acts as an immunogen that induces a T-cell dependent immune response. The CRM197 carrier protein provides T-cell epitopes that are recognized by T-helper cells after processing by antigen-presenting cells. This interaction facilitates B-cell isotype switching and the production of high-affinity IgG antibodies specific to the Neisseria meningitidis capsular polysaccharides, as well as the generation of memory B cells [1, 2, 4].