Footnotes

• Twitter @loeymak, @drpkennedy

• Contributors The authors declare they have participated in the preparation of the manuscript and have seen and approved the final version. L-YM—original drafting and revision of the manuscript. IB—reviewing and editing of the manuscript. PTFK—manuscript concept and design, interpretation of literature, critical revision of the manuscript and overall study supervision.

• Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.

• Map disclaimer The inclusion of any map (including the depiction of any boundaries therein), or of any geographic or locational reference, does not imply the expression of any opinion whatsoever on the part of BMJ concerning the legal status of any country, territory, jurisdiction or area or of its authorities. Any such expression remains solely that of the relevant source and is not endorsed by BMJ. Maps are provided without any warranty of any kind, either express or implied.

• Competing interests IB is a director at the International Concussion and Head Injury Foundation, and is medical consultant to the Global Performance Unit at City Football Group. PTFK has received research grants from Gilead Sciences; received consulting fees from Aligos Therapeutics, Antios Therapeutics, Assembly Biosciences, Gilead Sciences, GlaxoSmithKline, Janssen and Immunocore; and is the BASL HBV special interest group lead. L-YM has nothing to disclose.

• Provenance and peer review Commissioned; internally peer reviewed.