Men wear masks as they sit in the metro in Prague, Czech Republic, 17 March 2020. According to media reports, the Czech government decided to impose a two-week quarantine in the country on the evening of 15 March, and ban all international travel from 16 March 2020. Currently 383 cases of the coronavirus SARS-CoV-2, which causes the Covid-19 disease, have been officially confirmed in Czech Republic. (Photo by Martin Divisek/EPA/EFE)

A woman takes photographs of falling snow from a window during a heavy snowfall, amid the coronavirus disease (COVID-19) pandemic in Seoul, South Korea, January 12, 2021. (Photo by Kim Hong-Ji/Reuters)

A bus in New York City which careened off a road in the Bronx neighborhood of New York is left dangling from an overpass Friday, January 15, 2021, after a crash late Thursday that left the driver in serious condition, police said. (Photo by Craig Ruttle/AP Photo)

A man wearing a face mask as a precaution against the coronavirus, walks past in front of an advertisement of an opera performance outside of a theater in Seoul, South Korea, Wednesday, March 3, 2021. (Photo by Lee Jin-man/AP Photo)

Toure, a Gambian salt harvester, holds a basket filled with the salt collected from the crust of the bottom of the Lake Retba (Pink Lake) in Senegal on March 16, 2021. Lake Retba, divided from the Atlantic Ocean by a narrow corridor of dunes, owes its name to the pink waters caused by the Dunaliella salina algae and is known for its high salt content, up to 40% in some areas. (Photo by Marco Longari/AFP Photo)

People take a photo next to a blooming tree during cherry blossom season in Yuyuantan Park in Beijing, China on March 31, 2021. (Photo by Thomas Peter/Reuters)

Children play with their pet Hamster at a street in Kochi on March 29, 2021. (Photo by Arun Sankar/AFP Photo)

A prong extending from a remote-controlled robot prototype approaches the mouth of a volunteer to extract a throat swab sample, as part of a self-funded project to assist physicians in running tests on suspected COVID-19 coronavirus patients in a bid to limit human exposure to disease-carriers, at a private hospital in Egypt's Nile delta city of Tanta, on March 20, 2021. (Photo by Khaled Desouki/AFP Photo)