Author Contributions: Mr Scheller had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.
Acquisition, analysis, or interpretation of data: Scheller, Svanström, Pasternak, Arnheim-Dahlström, Sundström, Hviid.
Drafting of the manuscript: Scheller.
Critical revision of the manuscript for important intellectual content: Svanström, Pasternak, Arnheim-Dahlström, Sundström, Fink, Hviid.
Statistical analysis: Scheller, Svanström.
Obtained funding: Scheller, Pasternak, Arnheim-Dahlström, Hviid.
Administrative, technical, or material support: Fink.
Study supervision: Svanström, Pasternak, Hviid.
Conflict of Interest Disclosures: All authors have completed and submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Dr Arnheim-Dahlström reported receiving grants from MSD Sanofi Pasteur, Merck Sharp & Dohme, and GlaxoSmithKline for other studies. Dr Fink reported receiving travel support from Biogen Idec for other studies. Dr Hviid reported receiving a grant from the Novo Nordisk Foundation. No other authors reported disclosures.
Funding/Support: The Swedish Foundation for Strategic Research, Novo Nordisk Foundation, and The Danish Medical Research Council funded the study.
Role of the Funders/Sponsors: The study funders/sponsors had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication.
Additional Contributions: We thank Eva Herweijer, MSc (Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden), for database administration and the Public Health Agency of Sweden for contributing with human papillomavirus vaccine data from the Svevac register. Ms Herweijer received no compensation for her contributions.