This aerial photo shows bullet trains parked at a station in preparation for the upcoming Lunar New Year travel peak in Nanjing, in eastern China's Jiangsu province on January 27, 2021, as authorities have encouraged people to stay put during the Spring Festival to curb the spread of of COVID-19 coronavirus. (Photo by AFP Photo/China Stringer Network)

Ballet dancer Anoushka Zoe James dances in the water at the Ipanema beach in Rio de Janeiro, Brazil on October 29, 2020. (Photo by Pilar Olivares/Reuters)

Mortuary workers walk past a Christmas tree as they remove the body of an elderly person who died of COVID-19 from a nursing home in downtown Barcelona, Spain, Wednesday, December 23, 2020. (Photo by Emilio Morenatti/AP Photo)

Tourists wearing protective face masks walk in Nanluoguxiang alley, a famous touristic spot at Hutong neighborhood, in Beijing, China, 01 May 2020. China is loosening up nationwide restrictions after months of lockdown over the coronavirus crisis. Labor Day in the country kicked off with a long weekend and an extended holiday, from 01 to 05 May, after the tourism industry has been hit during the coronavirus and COVID-19 disease pandemic. (Photo by Roman Pilipey/EPA/EFE)

Visitors take photos of the fluorescent sea in the waters of Paishi Village, Dalian City, Liaoning Province, China, May 24, 2020, from the night of May 24 to the early morning of May 25, 2020. The fluorescent sea in dalian is caused by noctilucent algae in the sea water. (Photo by Costfoto/Barcroft Media via Getty Images)

A mask seller wearing a mask stands in a street market in Bangkok, Thailand, Tuesday, June 9, 2020. Daily life in capital resuming to normal as Thai government continues to ease restrictions related to running business in capital Bangkok that were imposed weeks ago to combat the spread of COVID-19. (Photo by Gemunu Amarasinghe/AP Photo)

Journalists wear face mask and keep distance as they attend news conference by German Health Minister Jens Spahn about the developing of the coronavirus crisis test strategy in Berlin, Germany, Thursday, August 6, 2020. (Photo by Markus Schreiber/AP Photo)

United States Air Force Academy graduates cheer as the United States Air Force Thunderbirds fly over the graduation for the Class of 2021 at Falcon Stadium on May 26, 2021 in Colorado Springs, Colorado. Chairman of the Joint Chiefs of Staff General Mark A. Milley gave the commencement address to the 1,019 graduates from the academy. (Photo by Michael Ciaglo/Getty Images)