Author Contributions: Drs van Gils and Sanders had full access to all of the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis. Drs van der Ende and Sanders contributed equally to the study.
Study concept and design: Sanders, Hak, van Alphen, van der Ende.
Acquisition of data: Van Gils, Veenhoven, Rodenburg, Bruin, Keijzers, Van der Ende.
Analysis and interpretation of data: Van Gils, Sanders, van der Ende, Veenhoven, Hak, van Alphen, Bogaert, Trzcinski.
Drafting of the manuscript: Van Gils, Sanders, van der Ende.
Critical revision of the manuscript for important intellectual content: van Gils, Sanders, van der Ende, Veenhoven, Hak, Rodenburg, Bogaert, Trzcinski, Keijzers, Bruin, van Alphen.
Statistical analysis: van Gils, van der Ende, Hak.
Obtained funding: Sanders.
Administrative, technical or material support: van Gils, Veenhoven, Rodenburg, Bruin, Keijzers, Van der Ende.
Study supervision: van der Ende, Sanders :
Financial Disclosures: Dr Veenhoven reported receiving grant support from GlaxoSmithKline and Wyeth/Pfizer for vaccine studies and consulting fees for GlaxoSmithKline. Dr Sanders reported receiving unrestricted grants from Wyeth/Pfizer and Baxter for research, consulting fees for Wyeth/Pfizer and GlaxoSmithKline, lecturing fees from Wyeth/Pfizer, and grant support from Wyeth/Pfizer and GlaxoSmithKline for vaccine studies. Dr Van der Ende reports receiving unrestricted grants from Wyeth/Pfizer and Novartis. For all other authors no potential conflicts were reported.
Funding/Support: This work was supported by the Dutch Ministry of Health.
Role of the Sponsor: The study sponsor played no role in the study design and conduct of the study, data collection, management, analysis, and interpretation of the data; and preparation, review, or approval of the manuscript.
Additional Contributions: We thank the participating children and their families for their time and effort. We also thank the members of the research team for their invaluable dedicated work and support. We thank all cooperating organizations for their support. We acknowledge the use of the pneumococcal MLST database, which is located at Imperial College London and is funded by Wellcome Trust.