Streptococcus Pneumoniae Type 4 Capsular Polysaccharide Antigen
Streptococcus pneumoniae type 4 capsular polysaccharide antigen is a purified bacterial component derived from the protective polysaccharide capsule of S. pneumoniae serotype 4. It is used as an active immunizing agent in pneumococcal vaccines to stimulate protective antibody responses against pneumococcal infections caused by this specific serotype.
A bacterial polysaccharide antigen used in vaccines to prevent pneumococcal infections caused by serotype 4.
Key facts at a glance
- RxNorm
- 854962
- Generic
- Streptococcus Pneumoniae Type 4 Capsular Polysaccharide Antigen
- Class
- unclassified
- Brands
- Pneumovax 23
- Availability
- rx
- Lactation
- unknown
- Routes
- —
- Forms
- prefilled syringe, injection, solution
- Regions
- US, EU, CN, JP
- Monitoring
- —
This page is for informational purposes only.
Do not use this information to diagnose yourself or to replace a physician's advice. Always consult a qualified healthcare provider before starting, stopping, or changing any medication. If you believe you are experiencing a medical emergency, call your local emergency number immediately.
Prevention of invasive pneumococcal disease, pneumonia, and bacteremia caused by Streptococcus pneumoniae serotype 4. May be included in polysaccharide pneumococcal vaccines (PPSV) or conjugate vaccines for individuals at risk of pneumococcal infections.
The capsular polysaccharide antigen stimulates the immune system to produce type-specific IgG antibodies that opsonize and facilitate clearance of S. pneumoniae bacteria bearing the type 4 capsule.
Polysaccharide antigens alone induce T-cell independent immune responses and may be less effective in young children under 2 years. Conjugation to a protein carrier (as in PCV vaccines) enhances immunogenicity. Not a treatment for active infection. Standard contraindications for vaccine components apply.
Official drug label
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This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 31, 2026. · Read our editorial policy