Around the world, wearing a face mask in public has been made compulsory for everyone. This includes Maryland, New York, New Jersey and Pennsylvania states in the US, municipalities in France, Taiwan, Austria, the Czech Republic, Solvakia, Lombardy and parts of Germany.
In many countries, wearing a mask is now recommended even if it is not mandatory. In the US, the Centers for Disease Control and Prevention (CDC) have recommended that people use at least use a simple cloth face covering when they are in public spaces. The German Ministry of Health has isssued similar guidance.
The mandating and recommending that the public wear face masks is based on the idea that wearing a mask reduces the chance of the person wearing the mask transmitting Covid-19 (“my mask protects you, your mask protects me.”).
The CDC issued its advice after reviewing recent evidence on the transmission of infections. A team of researchers led by data scientist Jeremy Howard has also carried out an evidence review to assess the effectiveness of face masks at reducing the spread of face masks. This found that:
“The preponderance of evidence indicates that mask wearing reduces the transmissibility per contact by reducing transmission of infected droplets in both laboratory and clinical contexts. Public mask wearing is most effective at stopping spread of the virus when compliance is high. The decreased transmissibility could substantially reduce the death toll and economic impact while the cost of the intervention is low. Thus we recommend the adoption of public cloth mask wearing, as an effective form of source control, in conjunction with existing hygiene, distancing, and contact tracing strategies.”
Professor Trisha Greenhalgh and colleagues have argued for the use of masks on a precautionary basis, despite the face that the “efficacy and acceptability of the different types of face mask in preventing respiratory infections during epidemics is sparse and contested”. There advice is as follows:
“In conclusion, in the face of a pandemic the search for perfect evidence may be the enemy of good policy. As with parachutes for jumping out of aeroplanes, it is time to act without waiting for randomised controlled trial evidence. A recently posted preprint of a systematic review came to the same conclusion. Masks are simple, cheap, and potentially effective. We believe that, worn both in the home (particularly by the person showing symptoms) and also outside the home in situations where meeting others is likely (for example, shopping, public transport), they could have a substantial impact on transmission with a relatively small impact on social and economic life.”
However, the WHO and UK are not currently recommending that everyone should wear a mask in public. This seems to be, at least partly, because they want to prioritise masks for health care workers and those who are showing symptoms of Coronavirus. However, the masks that it is being suggested the public wear are not surgical masks, but cloth masks that are different from those that are needed for healthcare settings.
Public Health England says the following about facemasks:
“Face masks play a very important role in clinical settings, such as hospitals but there’s very little evidence of widespread benefit from their use outside of these clinical settings. Facemasks must be worn correctly, changed frequently, removed properly and disposed of safely in order to be effective.”
Jeremy Howard and Professor Trisha Greenhalgh OBE have launched a campaign, Masks4All, calling for guidance for and mandating of the wearing of face masks in public. In the UK, London Mayor Sadiq Khan has also backed the wearing of face masks in public.
Reportedly, the Scientific Advisory Group for Emergencies (SAGE), which advises the government, has commissioned research on the effectivness of masks for limiting the spread of Coronavirus. There needs to be a clear timetable for that research. The research needs to be made available and a decision made about making mask wearing compulsory urgently. Unless SAGE and the government can provide a clear and compelling explanation for why face mask wearing should not be compulsory, then the UK should require everyone to wear face masks in public.