New research is highlighting the importance of wearing a mask.
A recent study suggests that not only do masks protect the wearer, but they may even reduce the severity of the coronavirus when someone is infected.
Related: Study suggests mask-wearing can lessen COVID-19 severity
The newly published theory says by wearing a mask you're only exposed to small amounts of the virus, if any, potentially building up a sort of immunity.
It is important to note that the research is still theoretical.
But the numbers show countries that "mask well" have lower rates of severe illness than countries that don't mask well.