Many people wear face masks in public to stop getting the virus, and it is recommended by countries such as China, Hong Kong and Thailand. Most face masks work best to stop you giving the virus to other people. When people with the virus wear masks they give it to less people. One study published in "Cell" showed that wearing a mask pulled down to cover the mouth but not the nose was not good. People usually breathe through their noses and not their mouths. Scientists found that nose cells were more likely to have virus in them than throat cells. Because of this, the scientists said, breathing out through the nose was more likely to spread the virus than breathing out through the mouth, so people should wear masks that cover their noses.