Streptococcus pneumoniae serotype 10A capsular polysaccharide (Pn10A) (Pn10A)

Streptococcus pneumoniae serotype 10A capsular polysaccharide is a complex carbohydrate polymer that serves as a primary virulence factor for the 10A strain of the bacterium (Bentley et al., 2006). In conjugate vaccines, it is covalently bound to CRM197, a non-toxic mutant of diphtheria toxin, to overcome the poor immunogenicity of pure polysaccharides in young children (Pichichero, 2013). This conjugation transforms the polysaccharide into a T-cell dependent antigen, facilitating the recruitment of T-helper cells and the subsequent production of high-affinity memory B cells (Pollard et al., 2009). The biological objective of targeting this molecule is to induce protective immunity, specifically through the generation of opsonizing antibodies that promote bacterial clearance by phagocytes (Hausdorff et al., 2000). Clinically, this target is addressed by multivalent vaccines such as V114 (Vaxneuvance) and PCV20 (Prevnar 20), which aim to reduce the burden of invasive pneumococcal disease, including pneumonia and meningitis (FDA, 2021; FDA, 2022).

Other names

Pneumococcal polysaccharide serotype 10AS. pneumoniae serotype 10A antigenPn10A-CRM197 conjugate10A-CRM197

Induces a T-cell dependent immune response through B-cell and T-helper cell activation, resulting in the production of opsonizing IgG antibodies and immunological memory against S. pneumoniae serotype 10A (Pollard et al., 2009).