pneumococcal vaccines

There are two types of pneumococcal vaccines available in the market, namely a 23-valent pneumococcal polysaccharide vaccine (23vPPV) and pneumococcal conjugate vaccines (PCV). 23vPPV consists of pneumococcal capsular polysaccharides for 23 pneumococci serotypes. PCV consists of pneumococcal capsular polysaccharides conjugated to carrier proteins. In Hong Kong, three types of PCV (PCV7, PCV10 and PCV13) consisting of antigens against seven, ten and thirteen pneumococci serotypes are registered.

http://www.chp.gov.hk/en/features/26868.html#FAQ1

Pneumococcal disease is an infection caused by Streptococcus pneumoniae bacteria, sometimes referred to as pneumococcus. Pneumococcus can cause many types of illnesses, including ear infections and meningitis.

https://www.cdc.gov/pneumococcal/about/index.html

A polysaccharide vaccine, which is made using a piece of the polysaccharide capsule that surrounds pneumococcal bacteria. A conjugate vaccine, which is made by joining a piece of the polysaccharide capsule that surrounds pneumococcal bacteria to a protein carrier.

https://www2a.cdc.gov/nip/isd/ycts/mod1/courses/genrec/10351.asp?seg=H

Serotype is a group of intimately related microorganisms distinguished by a common set of antigens.

https://www.merriam-webster.com/dictionary/serotype