PPSV23, or the 23-valent pneumococcal polysaccharide vaccine, is designed to protect against 23 types of Streptococcus pneumoniae bacteria. These bacteria can cause serious infections, including pneumonia, meningitis, and bloodstream infections. The vaccine is particularly recommended for older adults and individuals with certain health conditions that increase their risk of pneumococcal disease. The PPSV23 vaccine works by stimulating the immune system to recognize and fight off these specific bacteria. It is usually administered as a single injection and can be given to adults aged 65 and older, as well as younger individuals with specific health issues. It is important to consult a healthcare provider for personalized vaccination advice.