Neisseria meningitidis serogroup A, C, W, Y capsular polysaccharide–tetanus toxoid conjugate (MenACWY-TT) (MenACWY-TT)

The Neisseria meningitidis serogroup A, C, W, Y capsular polysaccharide–tetanus toxoid conjugate antigen is the active component of quadrivalent meningococcal vaccines designed to prevent invasive meningococcal disease. Neisseria meningitidis is a Gram-negative bacterium responsible for life-threatening meningitis and sepsis, with serogroups A, C, W, and Y being major contributors to the global disease burden [3]. While pure bacterial polysaccharides are poorly immunogenic in young children and do not induce immunological memory, their covalent conjugation to a tetanus toxoid carrier protein converts them into T-cell dependent antigens [4, 5]. This conjugation allows for the recruitment of T-helper cells, which facilitate B-cell maturation and the production of high-affinity bactericidal antibodies [1, 5]. These antibodies provide protection by promoting complement-mediated lysis and opsonophagocytosis of the bacteria [2]. Vaccines utilizing this conjugate antigen, such as Nimenrix and MenQuadfi, are essential for providing long-term protection against meningococcal disease across various age groups [1, 2].

Other names

Quadrivalent meningococcal conjugate vaccineMenACWY-TTMeningococcal A, C, W, Y-tetanus toxoid conjugateMeningococcal groups A, C, W-135 and Y conjugate vaccine

The vaccine antigen induces a T-cell dependent immune response. The tetanus toxoid carrier protein is processed by antigen-presenting cells and presented to T-helper cells, which provide signals to B-cells specific for the capsular polysaccharides of Neisseria meningitidis serogroups A, C, W, and Y. This leads to B-cell proliferation, isotype switching to IgG, and the generation of high-affinity bactericidal antibodies and memory B-cells [1, 2, 5].