I must make progress.
Scientific evidence also shows that all types of face coverings are to some extent effective in reducing the transmission of covid-19 in all settings. This is through a combination of source control, which limits the spread of the virus from a person, and protection to the wearer. Laboratory data shows that even non-medical masks, such as cloth masks made of two or three layers, may have similar filtration efficiency to surgical masks. As ever, we are guided by the advice of our scientific and medical experts. We will keep these measures under review, and we will take further action if necessary.