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)

Kyuta Kumagai, 10, wrestles with a boy the same age as him, during a training session at Buddy acL Ariake's wrestling club in Tokyo, Japan, August 22, 2020. (Photo by Kim Kyung-Hoon/Reuters)

An Iranian girl wearing a costume inspired in the fictional folklore character Hajji Firuz, dances in Tehran on March 17, 2021 as Iranians prepare to celebrate Noruz, the Iranian New Year. Noruz, “new day” in Persian, is the New Year festivity celebrated in Iran as well as in Afghanistan and Kurdish regions in several countries. It begins with the spring equinox and symbolises rebirth. (Photo by Atta Kenare/AFP Photo)

A Guarani boy pets a puppy in the Mata Verde Bonita village, in Marica, Rio de Janeiro state, Brazil, Thursday, February 25, 2020, where healthcare workers are making the rounds with coolers containing doses of China's Sinovac COVID-19 vaccine as part of a mass immunization program aimed at inoculating all of Rio's 16 million residents by the end of the year. (Photo by Bruna Prado/AP Photo)

A biker carrying huge bags of recyclables travels on a street outside Phnom Penh, Cambodia on Saturday, March 27, 2021. (Photo by Heng Sinith/AP Photo)

A health worker administers a dose of the Sinovac COVID-19 vaccine to a worker in a local entertainment venue area where a new cluster of COVID-19 infections were found in Bangkok, Thailand, Wednesday, April 7, 2021. Officials in Thailand’s capital have ordered a two-week closure of all entertainment venues in three districts to try to limit the spread of the coronavirus from nightspots there. (Photo by Sakchai Lalit/AP Photo)

A Filipino Catholic performing self-flagellation lies on the ground with his bloodied back outside a church on Good Friday, defying a government ban on religious gatherings amid rising coronavirus disease (COVID-19) cases, in Manila, Philippines, April 2, 2021. (Photo by Eloisa Lopez/Reuters)

Two women react to the camera as Nightclub Circus hosts the first dance event, which will welcome 6,000 clubbers to the city's Bramley-Moore Dock warehouse on April 30, 2021 in Liverpool, England. The event is part of the national Events Research Programme which will provide data on how events could be permitted to safely reopen. (Photo by Anthony Devlin/Getty Images)