Pneumococcal conjugate vaccine

Pneumococcal conjugate vaccine (PCV) is a pneumococcal vaccine and a conjugate vaccine used to protect infants, young children, and adults against disease caused by the bacterium Streptococcus pneumoniae (the pneumococcus). There are currently three types of PCV available on the global market, which go by the brand names: Prevnar (called Prevenar in some countries), Synflorix and Prevnar 13. Pneumococcal conjugate vaccine (PCV) is a pneumococcal vaccine and a conjugate vaccine used to protect infants, young children, and adults against disease caused by the bacterium Streptococcus pneumoniae (the pneumococcus). There are currently three types of PCV available on the global market, which go by the brand names: Prevnar (called Prevenar in some countries), Synflorix and Prevnar 13. The original Prevnar was produced from the seven most prevalent strains of S. pneumoniae bacteria in the US. The bacterial capsule sugars, a characteristic of these pathogens, are linked to CRM197, a nontoxic recombinant variant of diphtheria toxin (Corynebacterium diphtheriae). The vaccine's polysaccharide sugars are grown separately in soy peptone broths. Through reductive amination, the sugars are directly conjugated to the protein carrier CRM197 to form the glycoconjugate. CRM197 is grown in C. diphtheriae strain C7 in a medium of casamino acids and yeast extracts. The original seven-valent formulation contains serotypes 4, 6B, 9V, 14, 18C, 19F, and 23F, and results in a 98% probability of protection against these strains, which caused 80% of the pneumococcal disease in infants in the US. In 2010, Pfizer introduced Prevnar 13, which contains six additional strains (i.e., 1, 3, 5, 6A, 19A and 7F), which protect against the majority of the remaining pneumococcal infections.