Question to the Department of Health and Social Care:

To ask the Secretary of State for Health and Social Care, what peer-reviewed evidence UK Health Security Agency holds on the effectiveness of wearing face masks in public for the prevention of transmission of covid-19.

Throughout the COVID-19 pandemic, UK Health Security Agency (UKHSA) and one of its predecessor organisations, Public Health England, undertook and published multiple rapid evidence reviews on the effectiveness of face coverings in community settings for the prevention of transmission of COVID-19. The first review of the effectiveness of face coverings masks in non-healthcare settings was published on 26 June 2020, with the first updated published on 29 January 2021, followed by a second update on 9 November 2021.

The second update included 25 studies, two randomised controlled trials and 23 observational studies. Although the quality of the evidence was low/medium, it predominantly suggested that face coverings help to reduce the spread of COVID-19 in the community, through source control, wearer protection and universal masking. 14 of the 25 studies identified were peer-reviewed, nine were preprints and two were non-peer-reviewed reports. All studies were assessed by an experienced UKHSA evidence reviewer and checked by a second reviewer using the quality criteria checklist.

Due to the pace of the UKHSA COVID-19 pandemic response, independent peer review was not sought prior to publication but all evidence reviews have been subject to an internal quality assurance and formal clearance process prior to publication. All UKHSA publications contain information regarding evidence quality and review processes included for each subject reviewed.