The protection provided by face coverings varies greatly: 10-90% more protective than wearing nothing, depending on the size of the particles the person is exposed to and the fit of the covering. Studies have shown that surgical face masks are effective at reducing...

Face coverings are effective at reducing the amount of virus emitted by infected people. In general, face coverings are most effective at controlling transmission from an infected person when particle spread is greatest i.e., with “superspreading activities” such as...