Do masks stop the spread of viruses?

“The coronavirus causing Covid-19 is relatively large and the risk of transmission appears to be reduced by wearing a mask. The mask provides a physical barrier to help trap the virus,” Dr Sarah Brewer, Medical Director of Healthspan says.

“There is emerging evidence that wearing a mask when in contact with other people may help to reduce the spread of the disease - the mask provides some protection against coughed air droplets from others carrying the virus and, if you are a carrier, helps to protect others from catching the infection from you.”

Dr Christie Lewis, NHS GP, adds: “There is much debate and disparity on the rules surrounding masks in different countries. Several studies have researched whether masks provide an extra level of protection but there is not a conclusive outcome.

“There needs to be more robust studies undertaken therefore we can only follow the current guidance in the UK and by the World Health Organisation (WHO) which states that masks are NOT a substitute for social distancing, keeping two meters apart, or carefully washing your hands.”

What is the current advice around wearing masks in the UK?

The UK government is not currently advising most people to wear masks. But, this weekend, a group of more than 100 UK doctors wrote an open letter to The Times saying they were “alarmed at official inaction over the need for the public to wear homemade face masks”, which could be made by volunteer groups.

Chief scientific adviser Sir Patrick Vallance confirmed the issue was under review on 13 April, and the government’s Scientific Advisory Group for Emergencies (SAGE) is set to make recommendations to ministers. He said: “We would give new advice if we saw new evidence. As you know the WHO has stayed with their recommendation around masks, we look at this and update our view from time to time.”

Robert Peston asked a question about the public wearing face masks on tonight’s UK government daily coronavirus briefing (21 April).

Matt Hancock replied: “We are advised by the science and we’ve been asked this question many times. We listen to what the scientists say.” He said SAGE met today and he looks forward to hearing their updated advice around the public wearing face masks.

The European Centre for Disease Prevention and Control reported in April that the use of face masks in public may serve as a means of source control to reduce the spread of the infection in the community by minimising the excretion of respiratory droplets from infected individuals who have not yet developed symptoms or who remain asymptomatic.

It added that the use of face masks in the community should be considered only as a complementary measure and not as a replacement of the preventive measures already recommended including physical distancing, respiratory etiquette, meticulous hand hygiene and avoiding touching the face, nose, eyes and mouth.

The use of non-medical face masks could be considered, especially if – due to supply problems – medical face masks must be prioritised for use as personal protective equipment by healthcare workers. This is based on limited indirect evidence supporting the use of non-medical face masks as a means of source control.

Appropriate use of face masks is the key to the effectiveness of the measure and can be improved through education campaigns, the report adds.

Face masks: two doctors answer our questions about coronavirus masks