04 May 2020
Face masks could offer an important tool for contributing to the management of community transmission of Covid-19 within the general population, according to Data Evaluation and Learning for Viral Epidemics (DELVE). The multi-disciplinary group convened by the Royal Society supports a data-driven approach to learning from the different approaches countries are taking to managing the pandemic.
The group’s analysis suggests that the use of face masks, including home-made cloth masks, could reduce onward transmission if widely used in situations where physical distancing is not possible or predictable such as busy public transport, shopping and other potentially crowded public or workspaces. This contrasts to the standard use of masks for the protection of wearers. This is thought to be particularly important because a significant fraction of infected people are asymptomatic or presymptomatic and will not know that they are infectious.
The report highlights that in parallel with any policy recommending the use of homemade face masks for the general public, it will be necessary to take all steps to ensure sufficient supply of surgical masks as well as other PPE for frontline NHS workers.
The paper was submitted to the Government’s Scientific Advisory Group on Emergencies (SAGE).
DELVE welcomes the Prime Minister’s comments last week on the usefulness of face coverings and looks forward to hearing more details on Government plans.
Venki Ramakrishnan, Chair of the DELVE committee said; “While social distancing and maintaining hygiene, such as washing hands, remain of prime importance to reducing transmission, the evidence shows that, if used widely and correctly, face masks, including home-made cloth masks, can help to reduce viral transmission in situations where social distancing is difficult to maintain consistently. Such situations include busy public transport, shopping and other potentially crowded public or workspaces. The British public has shown a great willingness to take action to reduce the spread of this terrible pandemic and I am sure they would take this latest additional step. The more people who do this, the more effective it will be in helping us protect each other.
“The Government has to take many factors into account when making policy and it remains essential that NHS and other frontline workers who are risking their lives on our behalf must have access to medical face masks. Our top priority should be to protect the NHS and care workers, so the public should absolutely not be rushing out to get surgical masks. However, the scientific evidence shows that even home-made masks can help to reduce the spread of the virus.
“Many people may have the virus before symptoms kick in and some people will carry the virus without even knowing it. Every time they cough, sneeze, talk or even breathe, they are spreading droplets containing the virus. Covering your face can reduce the risk of infecting others but we emphasise that this is an added tool to bring down the infection rate, and not a replacement for handwashing and social distancing.”
Key points in the paper include:
DELVE’s report states that the evidence supports the conclusion that widespread face mask adoption in situations where social distancing is difficult to maintain consistently can help to control the Covid-19 epidemic by reducing the shedding of droplets into the environment from asymptomatic individuals. This is consistent with the experiences of countries that have adopted it.
The report also addresses implications of the science for policy makers:
The full report can be accessed at the DELVE initiative github: https://rs-delve.github.io/reports/2020/05/04/face-masks-for-the-general-public.html
DELVE is an independent group convened by the Royal Society. Its views do not necessarily reflect the views of the Royal Society
The Royal Society is providing a secretariat for DELVE
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