A cat sits on the empty Great Wall on February 23, 2021 in Beijing, China. Affected by the new coronavirus (COVID-19), the number of visitors to Mutianyu Great Wall in 2020 dropped by about 60%. (Photo by Lintao Zhang/Getty Images)

U.S. President Donald Trump holds news conference on the coronavirus outbreak at the White House in Washington, U.S., February 26, 2020. (Photo by Carlos Barria/Reuters)

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)

Volunteers throw a mixture of water, neem herb and turmeric as an alleged natural disinfectant on a street in a residential area during a government-imposed nationwide lockdown as a preventive measure against the COVID-19 coronavirus, in Chennai on April 7, 2020. (Photo by Arun Sankar/AFP Photo)

Local youth representatives dressed a Stormtrooper and Darth Vader (L-in black) from the Star Wars film franchise patrol in a wooden boat around a submerged village to remind residents to stay at home during the enhanced community quarantine in suburban Manila on May 6, 2020, as part of government's efforts to combat the spread of the COVID-19 coronavirus. (Photo by Ted Aljibe/AFP Photo)

Children are seen on a bike after Muslims in Nigeria perform Eid prayer following the global outbreak of coronavirus disease (COVID-19) in Nasarawa on May 24, 2020. (Photo by Afolabi Sotunde/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)

A woman walks up the steps decorated ahead of the Chinese New Year festival in Beijing, China, Thursday, January 12, 2017. The Chinese Lunar New Year is the most important holiday for Chinese and hundreds of millions are expected to return to their hometown to spend the new year with their family and relatives. (Photo by Ng Han Guan/AP Photo)