Do face masks protect against coronavirus? Here's what scientists know so far | David Heymann

Face masks are effective and vital in hospitals, but this doesn't mean they're useful for the general public

We all want to protect ourselves from coronavirus - but we need to make sure the things we're doing are effective. There are several measures we can all take to reduce the spread of Covid-19, including physical distancing, thorough handwashing, keeping surfaces clean, protecting the most vulnerable by staying home, and isolating ourselves if we have symptoms. We know from scientific evidence, as well as what we have learned from other countries further ahead in their epidemics, that these things work.

But what does the evidence say about how well face masks work, and who should wear them?