caption: A man walks on the Trocadero square in front of the Eiffel Tower in Paris, Wednesday, March 18, 2020. French President <PERSON> said that for 15 days people will be allowed to leave the place they live only for necessary activities such as shopping for food, going to work or taking a walk. For most people, the new coronavirus causes only mild or moderate symptoms. For some it can cause more severe illness, especially in older adults and people with existing health problems. (AP Photo/ <PERSON>)