About the Authors

Rebecca J. Cox

rebecca.cox@k2.uib.no

Affiliations Influenza Centre, Department of Clinical Science, University of Bergen, Bergen, Norway, Department of Research and Development, Haukeland University Hospital, Bergen, Norway, Jebsen Centre for Influenza Vaccine Research, University of Bergen, Bergen, Norway

Diane Major

Affiliation National Institute for Biological Standards and Control (NIBSC), Potters Bar, United Kingdom

Gabriel Pedersen

Affiliation Influenza Centre, Department of Clinical Science, University of Bergen, Bergen, Norway

Rishi D. Pathirana

Affiliations Influenza Centre, Department of Clinical Science, University of Bergen, Bergen, Norway, Department of Research and Development, Haukeland University Hospital, Bergen, Norway, Jebsen Centre for Influenza Vaccine Research, University of Bergen, Bergen, Norway

Katja Hoschler

Affiliation Respiratory Unit, Public Health England (PHE) Colindale, London, United Kingdom

Kate Guilfoyle

Affiliation National Institute for Biological Standards and Control (NIBSC), Potters Bar, United Kingdom

Sarah Roseby

Affiliation National Institute for Biological Standards and Control (NIBSC), Potters Bar, United Kingdom

Geir Bredholt

Affiliations Influenza Centre, Department of Clinical Science, University of Bergen, Bergen, Norway, Department of Research and Development, Haukeland University Hospital, Bergen, Norway, Jebsen Centre for Influenza Vaccine Research, University of Bergen, Bergen, Norway

Jörg Assmus

Affiliation Department of Research and Development, Haukeland University Hospital, Bergen, Norway

Lucy Breakwell

Affiliation Respiratory Unit, Public Health England (PHE) Colindale, London, United Kingdom

Laura Campitelli

Affiliation Istituto Superiore di Sanita (ISS), Rome, Italy

Haakon Sjursen

Affiliations Influenza Centre, Department of Clinical Science, University of Bergen, Bergen, Norway, Section for Infectious Diseases, Medical Department, Haukeland University Hospital, Bergen, Norway

Competing Interests

The authors have the following interests. Crucell provided the vaccine for this study. There are no further patents, products in development or marketed products to declare. This does not alter the authors' adherence to all the PLOS ONE policies on sharing data and materials, as detailed online in the guide for authors.

Author Contributions

Conceived and designed the experiments: RJC DM HS. Performed the experiments: RJC GP RDP KH KG SR GB LB LC HS. Analyzed the data: GP RDP RJC DM JA. Contributed reagents/materials/analysis tools: RJC DM KH LC. Wrote the paper: RDP RJC.