Haemophilus influenzae type b, Neisseria meningitidis serogroup A, and Neisseria meningitidis serogroup C capsular polysaccharide (Hib, MenA, and MenC CPS)

The capsular polysaccharides of Haemophilus influenzae type b (Hib), Neisseria meningitidis serogroup A (MenA), and Neisseria meningitidis serogroup C (MenC) are critical virulence factors that enable these bacteria to evade the host's immune system (Moxon & Kroll, 1988; Tzeng et al., 2016). These polysaccharides form a protective outer layer that inhibits phagocytosis and prevents complement-mediated lysis, allowing the pathogens to survive and proliferate in the bloodstream (Saha et al., 1997; Lewis & Ram, 2020). Hib is characterized by polyribosylribitol phosphate (PRP), while MenA and MenC consist of specific repeating units of N-acetylmannosamine-1-phosphate and N-acetylneuraminic acid, respectively (Bhattacharjee et al., 1975; Berry et al., 2002). In clinical practice, these polysaccharides serve as the primary antigens in conjugate vaccines, where they are chemically linked to carrier proteins to enhance immunogenicity, particularly in infants (Robbins et al., 1996; Richmond et al., 2001). Vaccination induces the production of protective bactericidal antibodies that recognize and neutralize the bacteria, significantly reducing the incidence of life-threatening diseases such as meningitis, pneumonia, and septicemia (Borrow et al., 2002; Finn et al., 2016). Common vaccines targeting these molecules include ActHIB, Menveo, and combination products like Menitorix and MenHibrix (Schneerson et al., 1980; Bryant et al., 2011).

Other names

Polyribosylribitol phosphatePRPMeningococcal group A capsular polysaccharideMeningococcal group C capsular polysaccharideBacterial capsular antigens

Induction of active immunity through the production of specific opsonophagocytic and bactericidal IgG antibodies against bacterial capsular polysaccharides.