Shanghai Ballet dancers wearing masks practise in a dance studio in Shanghai, China, as the country is hit by an outbreak of the novel coronavirus, February 20, 2020. (Photo by Aly Song/Reuters)

A man, wearing a protective mask following an outbreak of the coronavirus disease (COVID-19), walks in Tokyo, Japan on March 17, 2020. (Photo by Edgard Garrido/Reuters)

The Greyfriars Bobby statue is pictured wearing a mask as the spread of the coronavirus disease (COVID-19) continues, in Edinburgh, Scotland, Britain, March 23, 2020. (Photo by Russell Cheyne/Reuters)

A lady wearing a mask feeds pigeons in St James' Park, as the spread of the coronavirus disease (COVID-19) continues, London, Britain, April 5, 2020. (Photo by Henry Nicholls/Reuters)

A woman wears a mask with printed lips, amid the spread of the new coronavirus in Caracas, Venezuela, Thursday, April 30, 2020. (Photo by Ariana Cubillos/AP Photo)

Agriculture Secretary Sonny Perdue adjusts his mask before an event in the Roosevelt Room of the White House, Tuesday, May 19, 2020, in Washington. (Photo by Evan Vucci/AP Photo)

University students wearing Guy Fawkes masks pose for a photoshoot of a graduation ceremony to support anti-government protests at the Hong Kong Polytechnic University, in Hong Kong, China on October 30, 2019. (Photo by Tyrone Siu/Reuters)

People wearing masks and carrying supplies walk past a mannequin wearing a mask in downtown Barcelona, Spain, Saturday, March 14, 2020. Spain's prime minister has announced a two-week state of emergency from Saturday in a bid to contain the new coronavirus outbreak. 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. (Photo by Emilio Morenatti/AP Photo)