Face coverings for covid-19: from medical intervention to social practice.

Competing Interests: Competing interests: We have read and understood BMJ policy on declaration of interests and have the following interests to declare: HvdW is chairperson of the board and does unpaid advocacy for the non-governmental organisation TB Proof, which includes work on tuberculosis stigma and infection control. STC and NG receive funding for research related to covid-19 from the European Commission H2020 (101003589) and the UK Research and Innovation Covid-19 Emergency Fund. They do not receive direct funds for work on this topic. NG is co-chair of the WHO Covid-19 Research Roadmap social science working group. The views expressed in this paper are those of the authors and do not necessarily reflect those of the working group. TG has written several articles promoting the wearing of face coverings by the lay public as source control in covid-19; she has received no direct funding for her work on this topic but is principal investigator on grants from National Institute for Health Research (BRC-1215-20008), UK Research and Innovation (Covid-19 Emergency Fund), and Wellcome Trust (WT104830MA). Provenance and peer review: Not commissioned; externally peer reviewed.