Footnotes

• Contributors VST conceived the content of the manuscript, co-wrote and finalised the manuscript. CS co-wrote the manuscript and contributed to the final edit. AF conceived the content of the article, co-wrote the manuscript and performed the final edit.

• Competing interests VT is an ESPID Research Fellow and is currently undertaking research partially funded by a grant to the University of Bristol from Astra-Zeneca. AF undertakes consultancy and clinical research for all the main vaccine companies including most of those manufacturing flu vaccines. All funding related to these activities is paid to his employers, the University of Bristol and University Hospitals Bristol NHS Foundation Trust. He receives no personal remuneration related to these activities and has no other financial interest in these companies or any related intellectual property.

• Provenance and peer review Commissioned; internally peer reviewed.