Experts and ordinary people have both been divided about whether or not face masks should be worn in public. The World Health Organization said before that they should not be, but that's changing.
"WHO continues to gather all available evidence and continues to evaluate the potential use of masks more broadly to control COVID-19 transmission at the community level."
In recent weeks, COVID-19 has spread quickly in the U.S., Italy and Spain -- countries where mask-wearing is not common.
On the other hand, Asian countries that have encouraged or even required their people to wear masks have seen the virus spread much more slowly. South Korea and Hong Kong do recommend wearing masks at all times in public, and while Singapore does not, the government there has given out masks to keep at home just in case.
Now people in the U.S. are starting to wear masks and even President Trump has suggested covering the face with something.
"You know, you can use a scarf. A scarf is, everybody a lot of people have scarves and you can use a scarf. Scarf would be very good."
In Israel, the authorities have told people to wear masks in public places.
In Europe, the Czech Republic has made it mandatory to wear a mask when outside, and Austria now requires them at the supermarket.
The city of Jena in Germany has advised people to wear them when shopping or taking public transportion.
Jang TaeHyun, Arirang News