Streptococcus pneumoniae is a common cause of upper respiratory tract infection and community-acquired pneumonia (CAP). It also causes invasive pneumococcal disease (IPD) such as bacteremia, bacterial meningitis, endocarditis, and osteomyelitis. In 2012, there were an estimated 31 600 cases of pneumococcal infection and 3300 related deaths in the United States. The highest rates of infection are among children and adults aged 65 years or older.1