Footnotes

• Contributors Both authors have made substantial contributions to the creation of the manuscript, including conceptualisation, writing and revision, and take full responsibility for its contents.

• Disclaimer The findings and conclusions in this report are those of the author and do not necessarily represent the official position of the US Centers for Disease Control and Prevention.

• Competing interests None declared.

• Provenance and peer review Commissioned; internally peer reviewed.

• Data sharing statement This commentary does not include primary data.