23valent

23-valent pneumococcal polysaccharide vaccine, abbreviated PPSV23, is a vaccine that protects against invasive disease caused by Streptococcus pneumoniae serotypes included in the vaccine, totaling 23 distinct capsular polysaccharide types. It is used primarily in adults and in certain at-risk groups, to reduce the risk of invasive pneumococcal disease and some pneumococcal pneumonia.

PPSV23 is a polysaccharide vaccine. It induces a B-cell–mediated immune response that can be less robust in young children and does not consistently produce long-lasting immunological memory in this age group, which is why polysaccharide vaccines are generally not given to healthy children under 2 years old. For protection in young children, pneumococcal conjugate vaccines are used instead or in combination according to guidelines.

Indications vary by country but commonly include routine vaccination for adults aged 65 and older and for adults aged 19–64 with certain chronic or high-risk conditions, such as heart, lung, liver, or kidney disease, diabetes, alcoholism, smoking, cochlear implants, asplenia, or immunocompromising conditions. In many programs PPSV23 is given in a schedule that may involve sequencing with pneumococcal conjugate vaccines (PCV) according to national guidance.

Administration and dosing: PPSV23 is given as a single intramuscular or subcutaneous injection. Some high-risk individuals may be advised to receive a second dose after several years, depending on guidelines and the patient’s health status.

Safety and effectiveness: PPSV23 reduces the risk of disease caused by included serotypes, but its effectiveness against noninvasive pneumococcal pneumonia is variable. Common adverse effects are mild and include soreness at the injection site, redness, and fever; severe allergic reactions are rare.