Further, aluminum is also added to the vaccine serum because it is an adjuvant, meaning it further enhances the immune response.The vaccines 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 Prevnar seven-valent formulation contained serotypes 4, 6B, 9V, 14, 18C, 19F, and 23F, and resulted in a 98% probability of protection against these strains, which caused 80% of the pneumococcal disease in infants in the U.S. PCV7 is no longer produced.In 2010, Pfizer introduced Prevnar 13, which contains six additional strains (1, 3, 5, 6A, 19A and 7F), which protect against the majority of the remaining pneumococcal infections.In June 2021, the U.S. Food and Drug Administration (FDA) approved Prevnar 20, an icosavalent pneumococcal conjugate vaccine, which includes the serotypes 1, 3, 4, 5, 6A, 6B, 7F, 8, 9V, 10A, 11A, 12F, 14, 15B, 18C, 19A, 19F, 22F, 23F, and 33F for adults 18 years of age and older. As of August 2022, seven serotypes remain experimental and were authorized only under "accelerated approval" by FDA, based on opsonophagocytic activity ("OPA") assay. Maintenance of this approval is ongoing and "may be contingent upon verification and description of clinical benefit in a confirmatory trial. "In February 2022, the European Medicines Agency Approves Pfizers Prevnar 20 (PVC20) under the brand name Apexxnar. Synflorix
Synflorix (PCV10) is produced by GlaxoSmithKline.
Schedule of vaccination
As with all immunizations, whether it is available or required, and under what circumstances, varies according to the decisions made by local public health agencies. Children under the age of two years fail to mount an adequate response to the 23-valent adult vaccine, and so a pneumococcal conjugate vaccine is used. While this covers only seven strains out of more than ninety strains, these seven strains cause 80% to 90% of cases of severe pneumococcal disease, and it is considered to be nearly 100% effective against these strains. United Kingdom
The UK childhood vaccination schedule for infants born after 31 December 2019, consists of a primary course of one dose at twelve weeks of age with a second dose at one year of age. For infants born before 1 January 2020 and those in Scotland, the childhood vaccination schedule consists of a primary course of two doses at eight and sixteen weeks of age with a final third dose at one year of age.Children at special risk (e.g., sickle cell disease and asplenia) require as full protection as can be achieved using the conjugated vaccine, with the more extensive polysaccharide vaccine given after the second year of life:

United States
In 2001, the Centers for Disease Control and Prevention (CDC), upon advice from its Advisory Committee on Immunization Practices (ACIP), recommended the vaccine be administered to every infant and young child in the United States. The resulting demand outstripped production, creating shortages not resolved until 2004.