Streptococcus pneumoniae capsular polysaccharide serotype 16F (CPS 16F)

Streptococcus pneumoniae capsular polysaccharide serotype 16F is a complex carbohydrate structure that forms the outermost protective layer of the 16F serotype of the pneumococcus bacterium [1, 6]. Its primary biological function is to act as a major virulence factor by shielding the pathogen from the host's immune system, specifically by inhibiting opsonophagocytosis and complement-mediated killing [6, 11]. This allows the bacteria to colonize the nasopharynx and potentially invade sterile sites, leading to diseases such as pneumonia, meningitis, and bacteremia [5, 15]. Serotype 16F has gained clinical significance as an emerging non-vaccine serotype (NVT) following the widespread use of lower-valency conjugate vaccines like PCV13 and PCV20, which do not cover it [5, 13]. To address this, it has been included as a target antigen in next-generation vaccines, most notably the 21-valent pneumococcal conjugate vaccine (PCV21, Capvaxive) [13]. These vaccines work by inducing serotype-specific antibodies that recognize the 16F polysaccharide, facilitating the clearance of the bacteria by the immune system [4, 11].

Other names

Pneumococcal capsular polysaccharide serotype 16FS. pneumoniae serotype 16F capsular polysaccharide16F CPSSerotype 16F antigen

Active immunization via induction of serotype-specific antibodies that facilitate opsonophagocytic killing of the bacteria.