New insights on pneumococcal disease: what we have learned over the past decade.

Since the introduction of the seven-valent pneumococcal conjugate vaccine (PCV7) in 2000, significant reductions in the rate of invasive pneumococcal diseases (IPDs) and mucosal infections caused by vaccine-specific serotypes have been observed in the targeted population (children aged <5 years). IPD rates have also decreased in adults aged >/=65 years, suggesting the extension of vaccine protection to the unimmunized population. A concomitant decline has been noted in antibiotic-resistant Streptococcus pneumoniae isolates. The incidence of vaccine-serotype IPD varies widely in geographically disparate regions, indicating that serotype coverage alone may not accurately predict the impact of proposed pneumococcal conjugate vaccines with additional serotypes.