Streptococcus pneumoniae is a leading cause of bacterial pneumonia, meningitis, sinusitis, and acute otitis media in children and adults worldwide. Especially in the age group of < 2 years the incidence of invasive pneumococcal is high. The vulnerability of children to S. pneumoniae can also be demonstrated by the high rate of sequelae (> 20 % in Germany) and the high mortality (7.5 %) in pneumococcal meningitis. A 7-valent pneumococcal conjugate vaccine that was shown to be highly efficacious in preventing invasive pneumococcal disease in infants in the USA was licensed in Europe in 2001. It is expected that broad usage of the vaccine would reduce the incidence of invasive pneumococcal disease and the levels of pneumococcal resistance significantly.