A medical worker works at Intensive Care Unit in Sant'Orsola-Malpighi hospital in Bologna, Italy, on April 15, 2020. (Photos: Xinhua)

A man wearing a face mask works at the entrance of a supermarket in Geneva, Switzerland, on March 31, 2020.

Pedestrians wearing face masks are seen in Munich, Germany, April 27, 2020.

Doctor Hophelia is seen in Brussels, Belgium, April 24, 2020.

A man wearing a face mask walks past a graffiti in Athens, Greece, on April 28, 2020.