Footnotes

• 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.

• Competing interests None declared.

• Provenance and peer review Commissioned; internally peer reviewed.

• ↵Three examples: first, they characterise their article as ‘mak[ing] the case for recognising proof of natural immunity as an acceptable alternative to proof of vaccination’ (p. 2); second, when articulating their main thesis, they write, ‘if vaccine-induced immunity achieves a sufficient public health benefit to justify a vaccine mandate, [then] such mandates ought to consider evidence of recent infection as a sufficient basis for an exemption’ (ibid.); third, when posing their key question, which they answer in the affirmative, they ask, ‘whether, if a vaccine mandate is being applied, natural immunity would also achieve the public health benefits that are desired’ (p. 3).

• ↵Two examples: first, ‘for the purposes of immunity certification, those who have acquired immunity naturally are potentially equivalent to those who have acquired immunity through vaccination’ (p. 2, italics mine); second, ‘on the basis of existing data, it is plausible that naturally acquired immunity may be as good as vaccine-mediated immunity’ (p. 3, italics mine).