About the Authors

Elske J. M. van Gils

e.j.m.vangils@umcutrecht.nl

Affiliations Department of Pediatric Immunology and Infectious Diseases, Wilhelmina Children's Hospital, University Medical Center Utrecht, Utrecht, the Netherlands, Research Center Linnaeus Institute, Spaarne Hospital Hoofddorp, Hoofddorp, the Netherlands

Eelko Hak

Affiliations Department of PharmocoEpidemiology and PharmacoEconomics, University Medical Center Groningen, Groningen, the Netherlands, Department of Epidemiology, University Medical Center Groningen, Groningen, the Netherlands

Reinier H. Veenhoven

Affiliation Research Center Linnaeus Institute, Spaarne Hospital Hoofddorp, Hoofddorp, the Netherlands

Gerwin D. Rodenburg

Affiliations Department of Pediatric Immunology and Infectious Diseases, Wilhelmina Children's Hospital, University Medical Center Utrecht, Utrecht, the Netherlands, Research Center Linnaeus Institute, Spaarne Hospital Hoofddorp, Hoofddorp, the Netherlands

Debby Bogaert

Affiliation Department of Pediatric Immunology and Infectious Diseases, Wilhelmina Children's Hospital, University Medical Center Utrecht, Utrecht, the Netherlands

Jacob P. Bruin

Affiliation Regional Public Health Laboratory of Kennemerland, Haarlem, the Netherlands

Loek van Alphen

Affiliation Netherlands Vaccine Institute, Bilthoven, the Netherlands

Elisabeth A. M. Sanders

Affiliation Department of Pediatric Immunology and Infectious Diseases, Wilhelmina Children's Hospital, University Medical Center Utrecht, Utrecht, the Netherlands

Competing Interests

R.V. has received research support from GlaxoSmithKline and Wyeth/Pfizer for vaccine studies and consulting fees for GlaxoSmithKline. E.S. has received research support from Wyeth/Pfizer and Baxter, consulting fees for Wyeth/Pfizer and GlaxoSmithKline, lecturing fees from Wyeth/Pfizer, and grant support from Wyeth/Pfizer and GlaxoSmithKline for vaccine studies. These grants were not received for the research described in this paper. This does not alter our adherence to all the PLoS ONE policies on sharing data and materials. The other authors have declared that no competing interests exist.

Author Contributions

Conceived and designed the experiments: LV ES. Performed the experiments: EG GR JB. Analyzed the data: EG EH DB ES. Contributed reagents/materials/analysis tools: JB RV. Wrote the paper: EG EH RV GR DB JB LA ES.