PNEUMOVAX 23 is a vaccine designed to protect against pneumococcal disease caused by 23 types of pneumococcal bacteria. It is commonly administered to adults and children who are at increased risk for pneumococcal infections, including those with chronic health conditions, weakened immune systems, and individuals aged 65 years and older. PNEUMOVAX 23 works by stimulating the body's immune system to produce antibodies against pneumococcal bacteria, thereby providing immunity against infections such as pneumonia, meningitis, and bloodstream infections. The vaccine is given as a single injection, usually in the upper arm, and can provide long-lasting protection. It is an important preventive measure to reduce the risk of serious and potentially life-threatening pneumococcal diseases.