Pneumonia is a leading cause of death and hospitalization, costing health care systems billions of dollars and an estimated 600,000 adult deaths worldwide each year. Pneumococcal disease is caused by the bacterium Streptococcus pneumoniae and the term describes a group of illnesses, including invasive infections, such as bacteremia/sepsis and meningitis, as well as pneumonia and upper respiratory tract infections. Although all age groups may be affected, the highest rate of pneumococcal disease occurs in young children and older adults. In addition, persons suffering from a wide range of chronic conditions (eg, diabetes, cardiovascular disease) and immune deficiencies are at increased risk.