Streptococcus pneumoniae capsular polysaccharide serotype 19A (Spn CPS 19A)

Streptococcus pneumoniae capsular polysaccharide serotype 19A is a complex carbohydrate polymer that encapsulates the 19A strain of the pneumococcus bacterium, serving as its primary virulence factor [4, 8]. This polysaccharide layer protects the bacterium from the host immune system by inhibiting complement deposition and preventing opsonophagocytosis by neutrophils [6, 12]. Historically, serotype 19A became a prominent cause of invasive pneumococcal disease, including pneumonia, meningitis, and bacteremia, after the introduction of early vaccines that lacked this specific antigen [3, 14]. To address this, it was incorporated into modern multivalent vaccines such as PCV13, PCV15, and PCV20 [1, 5]. These vaccines utilize the polysaccharide, often conjugated to a carrier protein, to stimulate a robust immune response and generate protective antibodies [7, 11]. Clinical efficacy is typically monitored through the measurement of serotype-specific IgG levels and opsonophagocytic activity (OPA) titers in the blood [1, 16].

Other names

Pneumococcal polysaccharide serotype 19ACPS19ASerotype 19A capsular polysaccharidePneumococcal capsular polysaccharide 19A19A CPS

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