Streptococcus Pneumoniae Type 18C Capsular Polysaccharide Antigen
Streptococcus pneumoniae type 18c capsular polysaccharide antigen is a vaccine component that stimulates the immune system to develop protection against pneumococcal disease caused by serotype 18c. It is used as part of pneumococcal conjugate vaccines, primarily for immunization against serious infections such as pneumonia, meningitis, and bloodstream infections in infants, young children, and high-risk individuals.
A vaccine antigen that provides immunity against Streptococcus pneumoniae serotype 18c, a bacterium responsible for serious respiratory and invasive infections.
Key facts at a glance
- RxNorm
- 854944
- Generic
- Streptococcus Pneumoniae Type 18c 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, meningitis, and bloodstream infections caused by Streptococcus pneumoniae serotype 18c. Commonly included in childhood immunization programs and for adults with certain risk factors such as immunocompromised states or chronic health conditions.
The capsular polysaccharide antigen stimulates the immune system to produce type-specific antibodies against the polysaccharide capsule of S. pneumoniae serotype 18c. In conjugate formulations, the polysaccharide is linked to a protein carrier to enhance immunogenicity, particularly in young children whose immune systems do not respond well to polysaccharide antigens alone.
This is a vaccine antigen component, not a standalone medication, and is always administered as part of a multivalent vaccine covering multiple pneumococcal serotypes. As with all vaccines, protection depends on individual immune response, and this component does not protect against non-18c serotypes of S. pneumoniae or other bacteria causing similar diseases.
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