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The department of Health have issued new guidance on face coverings in England.
Dr David Strain, Senior Clinical Lecturer, University of Exeter, said:
“There is no logic to the exclusion of theatres and cinemas. Even if an individual can be physically distanced in the auditoria (which is unlikely) and the ventilation systems can be appropriately modified, co-ordinating entrances and exit or use of toilet facilities will be impossible. Similarly there is no reason why shop keepers or supermarket staff should be exempt. As has been repeatedly said, the evidence for masks in COVID-19 is limited, in no small part because of the short time that this has been in circulation. However the very strong epidemiological evidence from previous coronaviral outbreaks including SARS and MERS have demonstrated a 70% reduction in virus transmission in health care settings and 44% reduction in community transmission.
“We need clarity from the government that emphasises that COVID is still in circulation and that whenever an individual cannot maintain 2m physical distance, irrespective of whether they are shopper or shopkeeper, whether at the supermarket or theatre, face coverings (masks) should be used in conjunction with hand washing and other hygiene measures to minimise the spread so that we can return to normal life as soon as possible.”
Prof Jeremy Rossman, Honorary Senior Lecturer in Virology, University of Kent, said:
“The news of a broader requirement for the use of face coverings is a welcome policy addition, as face coverings have been shown to be highly effective at reducing COVID-19 transmission. Unfortunately there are some exemptions from these requirements that could limit the benefit of this policy, such as not requiring staff to also wear masks and exempting certain venues such as cinema and hair dressers. It is also important to note that we still need to be practicing physical distancing and hand washing and that we still have a strong need for robust national testing and tracing infrastructure. However, combined together, face coverings, physical distancing, hand washing, testing and tracing offers a highly effective way to minimise and control virus transmission until (and if) we have a vaccine.”
Prof Noel McCarthy, Professor in Population Evidence and Technologies, Warwick Medical School, said:
“The best estimate, from very early in pandemic as articulated by Greenhalgh and others (https://www.bmj.com/content/bmj/369/bmj.m1435.full.pdf), has been that face covering may substantially reduce transmission and should be adopted in closed indoor spaces. Advice coming in line with this and increasing additional pieces of evidence to support this position is welcome.
“Unfortunately, while the risks of transmission will vary by indoor setting and activity, and the relative contribution of masks compared to other measures will also vary, there is no good data to guide these decisions which instead rely on expert assessment of features such as the ability to maintain social distancing at 2 metres. However the relevance of this in indoor spaces is very uncertain so that the foundations of selecting which places count and which do not is necessarily estimated rather than based on firm data and analysis.
“Combined distancing and face coverings are likely to have stronger effects than either alone.
“This lack of a firm quantitative estimate is a real problem. If masks work well then these measures may be very long term. This makes it very important that we move from uncertainty to good estimates of the extent of risk and of protection offered by masks in different settings. The ideal way to do this would be community trials of mask wearing versus no compulsory mask wearing that could give quantitative estimates of benefit, but can only be done when there are moderately high levels of virus circulating.
“Without community trials natural experiments may allow some measures of which indoor areas are supporting transmission. These could be evaluated by studies that track and analyse the pattern of indoor air exposures of cases as they are identified through Test and Trace.”
Dr Bryan Bzdek, Research Fellow at Bristol Aerosol Research Centre, University of Bristol, said:
How strong is the evidence that face coverings have a part to play in reducing transmission of the virus?
“Face coverings reduce the emission of large droplets that sediment within 1-2 m of the emitter because they will impact against the covering. However, most face coverings are unlikely to substantially reduce emission of much smaller aerosol droplets, which follow the gas flow around the mask. Although both large droplets and small aerosols may carry the virus, face coverings help to reduce transmission via large droplets as well as reduce transmission by frequently touched surfaces, assuming that people avoid touching their faces and their face coverings while wearing it.
Is it still important that people still do social distancing and hand washing despite face coverings being mandatory in more places?
“It is essential that social distancing and hand washing continue to be normal practice. A face covering supplements these precautions; it does not replace them.”
Dr Simon Clarke, Associate Professor of Cellular Microbiology at the University of Reading, said:
“While the most effective barrier to avoid catching Covid-19 is your front door, as restrictions on movement and activities are coming to an end, the infection peak has reduced, and we have more evidence from around the world, it is time that the government refreshes its entire package of advice on reducing infections.
“Today’s announcement has taken into account recent scientific reports which provide some evidence for updating advice on face masks. Reducing infections requires a complete package of behavioural change, and facemask wearing should not be seen as an end in itself. While the DHSC’s advice includes points on washing and handling, there also needs to be specific information about the importance of fit, cleanliness and maintenance of masks to ensure they are doing their job. Such advice needs to be widely stated to ensure that wearing masks and face coverings provide the best possible benefit to reduce infections.”
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www.sciencemediacentre.org/tag/covid-19
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