Streptococcus Pneumoniae Type 19A Capsular Polysaccharide Antigen
Streptococcus pneumoniae type 19a capsular polysaccharide antigen is a vaccine component used to generate immunity against pneumococcal disease caused by serotype 19a. This serotype is a significant cause of invasive pneumococcal disease including pneumonia, meningitis, and bloodstream infections. The antigen is included in pneumococcal conjugate vaccines to broaden protection against multiple disease-causing strains, particularly in young children and older adults.
A vaccine antigen that provides protective immunity against Streptococcus pneumoniae serotype 19a, a common cause of serious infections including pneumonia and meningitis.
Key facts at a glance
- RxNorm
- 854946
- Generic
- Streptococcus Pneumoniae Type 19a 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 caused by S. pneumoniae serotype 19a, including pneumonia, meningitis, bacteremia, and acute otitis media. Included in pneumococcal conjugate vaccines recommended for infants, young children, older adults, and immunocompromised individuals at increased risk for pneumococcal infections.
The capsular polysaccharide antigen is chemically conjugated to a carrier protein (such as CRM197, tetanus toxoid, or diphtheria toxoid) to enhance immunogenicity, particularly in young children whose immune systems do not respond well to polysaccharides alone. This conjugation stimulates T-cell dependent immune responses, leading to robust production of serotype-specific antibodies that neutralize the bacterium.
This is a vaccine antigen component, not a therapeutic medication. Protection is serotype-specific, and additional antigens are needed to cover other pneumococcal strains. Common adverse reactions include injection site pain, redness, swelling, fever, and irritability in children. Contraindicated in individuals with severe hypersensitivity to any vaccine component. Administered as part of standard immunization schedules, not as standalone treatment for active infection.
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