Should Pneumococcal Vaccines Eliminate Nasopharyngeal Colonization?

Streptococcus pneumoniae remains an important human pathogen. For more than 100 years, there have been vaccine efforts to prevent pneumococcal infection. The pneumococcal conjugate vaccines have significantly reduced invasive disease. However, these vaccines have changed pneumococcal ecology within the human nasopharynx. We suggest that elimination of the pneumococcus from the human nasopharynx can have consequences that should be considered as the next generation of pneumococcal vaccines is developed.