The Centers for Disease Control and Prevention issued its strongest endorsement yet for the widespread wearing of masks, saying Tuesday that face coverings protect both the wearer and those around them from the spread of COVID-19.

Adopting universal masking policies can help avert future lockdowns, especially if combined with other non-pharmaceutical interventions such as social distancing, hand hygiene, and adequate ventilation, the CDC wrote in a scientific briefing .

The updated guidance is the agencys most overt statement on mask-wearing, issued as the country endures the worst phase of the pandemic so far. More than 10 million Americans have now tested positive for COVID-19, with 1 million new cases of the virus in November alone (even though we are just 10 days into the month). The number of hospitalizations for the virus has hit an all-time high , and the country has averaged more than 116,000 new cases each day for the past week.

The CDC said Tuesday that COVID-19 spreads predominantly through respiratory droplets generated when people cough, sneeze, sing, talk, or breathe. Masks help prevent infected people from spreading those droplets and also help keep healthy people from inhaling them.

In a message more specific than others it has issued on the topic, the CDC also said that even a 15% increase in mask-wearing throughout the U.S. could save $1 trillion in economic losses and avert future shutdowns.