Capsular polysaccharide of Streptococcus pneumoniae serotype 9V (CPS 9V)

The capsular polysaccharide of Streptococcus pneumoniae serotype 9V is a complex carbohydrate structure that forms the outermost layer of the bacterium. It serves as a primary virulence factor by shielding the pathogen from the host's innate immune system, specifically by inhibiting opsonophagocytosis and interfering with the complement system. Serotype 9V is a significant cause of invasive pneumococcal diseases, including pneumonia, meningitis, and bacteremia, particularly in children and the elderly. Due to its high prevalence and pathogenicity, it is a key antigenic component in several multivalent vaccines, such as the 13-valent, 15-valent, and 20-valent pneumococcal conjugate vaccines (PCVs), as well as the 23-valent polysaccharide vaccine (PPSV23). These vaccines function by stimulating the production of serotype-specific antibodies that facilitate the recognition and clearance of the bacteria by phagocytic cells.

Other names

Pneumococcal polysaccharide serotype 9VPn9VCPS 9VStreptococcus pneumoniae type 9V capsular polysaccharide

Induction of serotype-specific IgG antibodies leading to opsonization and phagocytosis of the bacteria.