Do face coverings protect against COVID-19?
Face coverings are a controversial part of the fight against COVID-19, the guidance has changed regularly with many scientists not being able to agree on their effectiveness.
At the start of the pandemic, it was unknown that some carriers would be asymptomatic and therefore spread the virus undetected. It was also unknown that the incubation period was five to six days on average and during that time a carrier could still infect other people.
Before these facts were known, the official guidance from bodies such as the WHO said that face coverings would do little unless you were in already in close contact with an infected person. But after these discoveries, it became clear that it was impossible to tell who has been infected without a test and maybe wearing face mask would be a sensible precaution for everybody.
The primary purpose of a face covering is to protect both the wearer and nearby people from sharing potentially infected particles, such as saliva, through the air. As this is thought to be the most common transmission of COVID-19, this should reduce exposure to the virus and in turn reduce the infection rate.
It is particularly important to wear face coverings in public spaces, indoors and busy places were maintaining 2 metre social distance is difficult or impossible. The higher the congestion of people, the higher the risk of airborne infection which means that a face covering is required most.
Study results differ on the effectiveness of masks against transmission. One study from USA determines that the risk of transmission when wearing a face covering reduces from 17% to 3%.
It also depends on which type of face covering you choose. The most effective type is a factory engineered respirator mask with a built-in valve. These are thought to reduce the risk of the wearer being infected and also passing on the infection greatly.
The second most effective type of face covering is a surgical or medical mask. It’s unsure to what extent they protect the wearer, but studies have shown that they protect nearby people by catching a good proportion of the droplets which could otherwise be spread.
Lastly, cloth face coverings are the most commonly used and offer the lowest level of protection for everybody. The fabric, such as cotton, which is the face covering is made up of will catch some of the droplets exhaled by the wearer. The tighter the fabric is woven and the thicker the layer of fabric used to construct the face covering the better.
Most importantly, cloth face coverings should never be shared, they should be washed after use (preferably at 60 degrees) and you should wash your hands before putting the mask on or taking it off.