Pneumococcal infections are caused by the bacterium Streptococcus pneumoniae, which can lead to various illnesses, including pneumonia, meningitis, and bloodstream infections. These infections are particularly serious for young children, the elderly, and individuals with weakened immune systems. Transmission occurs through respiratory droplets when an infected person coughs or sneezes. Vaccines are available to help prevent pneumococcal infections, reducing the risk of severe illness and complications. Early diagnosis and treatment with antibiotics are crucial for effective management of these infections.