How well do face masks protect against coronavirus?

How well do face masks protect against coronavirus? ：
Can face masks help slow the spread of the coronavirus (SARS-CoV-2) that causes COVID-19? Yes. Face masks combined with other preventive measures, such as getting vaccinated, frequent hand-washing and physical distancing, can help slow the spread of the virus.

The U.S. Centers for Disease Control and Prevention (CDC) recommends fabric masks for the general public. If you’re fully vaccinated and are in an area with a high number of new COVID-19 cases, the CDC recommends wearing a mask indoors in public and outdoors in crowded areas or when you are in close contact with unvaccinated people. People who haven’t been fully vaccinated should wear face disposable masks indoors and outdoors