Pneumococcal polysaccharide–CRM197 conjugates adsorbed to aluminum phosphate (PCV-CRM197)

Pneumococcal polysaccharide–CRM197 conjugates adsorbed to aluminum phosphate is a vaccine formulation used to provide active immunization against Streptococcus pneumoniae. It consists of purified capsular polysaccharides from multiple pneumococcal serotypes, each covalently linked to CRM197, a non-toxic mutant of the diphtheria toxin [1]. This conjugation is essential because pure polysaccharides are T-cell independent antigens that do not elicit a strong immune response or memory in infants; the CRM197 carrier converts them into T-cell dependent antigens [2][3]. The formulation is adsorbed onto aluminum phosphate, which serves as an adjuvant to enhance the immune response by stimulating local inflammation and antigen uptake [4]. This technology is the foundation of widely used vaccines like Prevnar 13 and Prevnar 20, which have significantly decreased the incidence of pneumococcal pneumonia and meningitis globally [5].

Other names

Pneumococcal conjugate vaccinePCVPrevnarPrevenar13-valent pneumococcal conjugate vaccine20-valent pneumococcal conjugate vaccinePCV13PCV207-valent pneumococcal conjugate vaccinePCV7

The vaccine induces a T-cell dependent immune response where the CRM197 carrier protein allows the polysaccharide antigens to be processed by antigen-presenting cells and presented to T-helper cells, leading to B-cell maturation, high-affinity antibody production, and immunological memory [1][2].