Pneumococcal capsular polysaccharide serotype 4 (CPS4)

Pneumococcal capsular polysaccharide serotype 4 is a complex carbohydrate polymer that forms the protective outer capsule of Streptococcus pneumoniae serotype 4 [3, 10]. It serves as a primary virulence factor by shielding the bacterium from host immune recognition and inhibiting opsonophagocytic clearance by neutrophils and macrophages [8, 10]. This polysaccharide is highly immunogenic and is a key antigenic component in several multivalent vaccines, including conjugate vaccines such as Prevnar 13 (PCV13) and Prevnar 20 (PCV20), as well as the 23-valent polysaccharide vaccine Pneumovax 23 (PPSV23) [1, 6]. Vaccination with these products stimulates the production of serotype-specific IgG antibodies that facilitate the opsonization and subsequent destruction of the pathogen [1, 11]. Serotype 4 is historically associated with high invasiveness and is a significant cause of pneumonia, meningitis, and bacteremia globally [4, 12]. While widely covered by current vaccines, its prevalence is monitored due to the potential for serotype replacement and geographic variations in disease burden [4, 5].

Other names

Streptococcus pneumoniae serotype 4 capsular polysaccharidePPS4Pneumococcal polysaccharide serotype 4Streptococcus pneumoniae type 4 capsular polysaccharide antigen

Induction of active immunity through the production of serotype-specific opsonophagocytic antibodies that facilitate bacterial clearance by the host immune system.