At various stages of the COVID-19 pandemic, face coverings have been recommended and encouraged as one of the interventions to reduce transmission of the SARS-CoV-2 virus. However, in the earlier stages of the pandemic, decisions on face coverings relied primarily on evidence based on other viral respiratory infections. More direct evidence on the use of face coverings with COVID-19 developed in tandem with the pandemic.

Health Technology Wales undertook an ultra-rapid review to inform national guidelines, the work assessed the evidence on the effectiveness of face coverings to reduce SARS-CoV-2 transmission. We also reviewed evidence on the efficacy of different types of face coverings.

We conducted a systematic literature search for evidence to address (i) the effectiveness of face coverings to reduce the spread of COVID-19 in the community, and (ii) the efficacy of different types of face coverings designed for use in community settings. We identified a rapid review in 2021 by Public Health England that closely aligned with our review questions. This provided the main source for identifying relevant studies, supplemented by a search for publications following their search date.

We identified two evidence reviews (including the Public Health England review) that examined the effectiveness of face coverings on reducing transmission of SARS-CoV-2; reporting on 31 and 39 studies, respectively. Two further primary studies were published after the two evidence review searches were included. Overall, the evidence suggested that face coverings may provide benefits in preventing SARS-CoV-2 transmission, although the higher-quality studies suggested that these benefits may be modest. Medical masks appeared to have higher efficacy than fabric masks, although the evidence was mixed.

At the time of this review, evidence on the effectiveness of face coverings remains limited and conclusions rely on low-quality sources of evidence with high risk of bias, although higher-quality evidence points to some benefit. Face coverings may play a role in preventing transmission of SARS-CoV-2, particularly as part of a bundle of other preventative measures.