pneumococcal polysaccharide conjugate vaccine

Pneumococcal polysaccharide-protein conjugate vaccines (PCVs) are a class of vaccines designed to prevent invasive diseases caused by the bacterium *Streptococcus pneumoniae*, such as pneumonia, meningitis, and febrile bacteremia. Unlike pure polysaccharide vaccines, PCVs covalently link (conjugate) the bacterial capsular polysaccharides to a carrier protein (e.g., CRM197, tetanus toxoid, or diphtheria toxoid). This conjugation is critical because it transforms the T-cell independent polysaccharide antigens into T-cell dependent antigens, enabling the recruitment of T-helper cells. This process induces a robust immune response, high-affinity antibody production, and long-term immunological memory, which is particularly effective in infants and young children whose immune systems do not respond well to plain polysaccharides. Various formulations exist targeting different numbers of serotypes (e.g., 7, 10, 13, 15, 20, or 21-valent).

Brand names

PrevnarPrevenarVaxneuvanceSynflorixPneumosilCapvaxive

Other names

pneumococcal conjugate vaccinepneumococcal polysaccharide-protein conjugate vaccine