The State Council ’s Joint Prevention and Control Mechanism held a press conference on the prevention and control of the COVID-19 epidemic and medical diagnosis and treatment on March 24. Wu Zunyou, a researcher at the China Centers for Disease Control and Prevention, said that there is almost no virus in the environment of low-endemic areas, and it is safe to not wear a mask. The National Health and Health Commission has issued public guidelines for wearing masks. There is no need to wear a mask in the open environment at home. The general population still needs to wear a mask when going to crowded places or having close contact with people.