A new study is putting a number on the lives that could be saved if everyone wore a facial covering while out in public during the COVID-19 pandemic.

“We have clear scientific evidence that they work and they are our best defense,” says Centers for Disease Control and Prevention Director Dr. Robert Redfield.

Health experts say that wearing a mask is the best way to stop the spread of the virus. And a new modeling study in the journal "Nature Medicine" estimates that more than 100,000 lives could be saved between now and February if everyone wore one. But researchers note that as of late-September, less than half of Americans reported that they always wear a mask in public.

If this trend remains through February and states continue with removing social distancing mandates, the study suggests that the COVID-19 death toll across the U.S. could reach 1 million deaths by the end of February. Researchers say that if states shut down when their daily date rate exceeds eight deaths per 1 million people and mask wearing doesn’t change, the forecasted death toll could reach more than 511,000 by the end of February.

But if most Americans wear masks and states reimpose social distancing mandates if the death rates sharply rise, the death toll projection would be at its lowest.

Researchers analyzed COVID-19 data from the beginning of February through the third week of September. They used those numbers, along with other factors, to help determine projects for the pandemic through February. The study was not definitive of what the future holds.