The heptavalent pneumococcal conjugate vaccine (PCV7) that has been recommended since the year 2000 for all US children younger than 2 years has been a towering success. Childhood PCV7 vaccination has resulted in much greater reductions in invasive disease in young children, as well as older children and adults through herd immunity, than had been anticipated.1-4 From 2001 through 2005, Active Bacterial Core surveillance of the Centers for Disease Control and Prevention showed that the US burden of invasive pneumococcal disease decreased by more than 100 000 cases, including about 2000 cases of meningitis and 25 000 cases of pneumonia with bacteremia. Invasive disease occurred in 188 per 100 000 US children younger than 2 years before PCV7 licensure. In 2005, 5 years after PCV7 licensure, rates of invasive disease decreased 81% to 36 per 100 000 children.5 The success of this vaccine is underscored by the recent recommendation of the World Health Organization to include PCV7 in national immunization programs worldwide.6