The 23-valent pneumonia vaccine, also known as the pneumonia polysaccharide vaccine, protects against pneumococcal disease caused by 23 pneumococcal serotypes. Approximately 90% of pneumonia is caused by 23 serotypes and can be administered to people over 2 years of age. Protective antibodies can be produced within approximately 2-3 weeks after vaccination, and the protection rate can reach about 92%, and its immune function can be maintained for 5 years. However, the vaccine cannot be used for prevention in children under 2 years of age because the immune system function is not fully developed and the vaccine cannot stimulate an effective immune response in babies under 2 years of age. babies under 2 years of age can receive the HIB vaccine, also known as Haemophilus influenzae type B vaccine, which can prevent bronchopneumonia and other infectious diseases caused by Haemophilus influenzae type B. 23-valent The 23-valent pneumonia vaccine is not part of the national basic immunization, but is a fee-based program that is administered at the discretion of the family.