Streptococcus pneumoniae serotype 24F capsular polysaccharide (24F CPS)

The Streptococcus pneumoniae serotype 24F capsular polysaccharide is a complex carbohydrate polymer that serves as the primary virulence factor for the 24F serotype of the pneumococcus bacterium. Its biological role involves providing a physical barrier that protects the pathogen from host immune recognition, specifically by preventing opsonization and phagocytosis by immune cells [1]. Serotype 24F has gained clinical prominence as an emerging serotype, contributing significantly to invasive pneumococcal diseases such as meningitis, bacteremia, and pneumonia, especially in regions where earlier-generation vaccines lacked coverage for this specific strain [2]. As a therapeutic target, the 24F capsular polysaccharide is incorporated into advanced pneumococcal conjugate vaccines (PCVs), such as the 21-valent vaccine V116 (Capvaxive), to stimulate the production of protective antibodies [3]. These vaccine-induced antibodies recognize the polysaccharide structure, enabling the host's immune system to effectively neutralize and clear the bacteria via opsonophagocytic killing [4]. Therapeutic challenges include the potential for serotype replacement, where other non-vaccine serotypes fill the ecological niche left by the reduction of 24F [5].

Other names

Pneumococcal serotype 24F capsular polysaccharideSpn24F CPSType 24F pneumococcal polysaccharideStreptococcus pneumoniae serogroup 24 polysaccharide

Induction of serotype-specific humoral immunity and opsonophagocytic activity against Streptococcus pneumoniae serotype 24F.