A health worker applies a dose of the AstraZeneca vaccine during the first day of a three-day COVID-19 vaccination campaign for people over age 35 in the Complexo da Maré favela of Rio de Janeiro, Brazil, Brazil, Thursday, July 29, 2021. Some recipients will be monitored to study the rate of protection the vaccines provide and the extent to which virus variants are circulating. (Photo by Bruna Prado/AP Photo)

Behishta,11, listens during 4th grade class at the Zarghoona high school on July 25 2021 in Kabul, Afghanistan. The Zarghoona girls high school is the largest in Kabul with 8,500 female students attending classes. The school opened after a nearly two-month break due to the coronavirus (COVID-19) pandemic. (Photo by Paula Bronstein/Getty Images)

A British RAF Typhoon aircraft escorts a C130 transport plane on its way to Jordan for an airdrop of paratroopers from the U.K.'s 16th Air Assault Brigade as part of an exercise conducted jointly with Jordanian soldiers on Wednesday, June 23, 2021. (Photo by Petros Karadjias/AP Photo)

Children jump over a puddle of water as they play during a rainstorm on a street in Barcelona, Spain, Saturday, September 18, 2021. (Photo by Emilio Morenatti/AP Photo)

A Palestinian man dressed as Santa Claus gestures as he rides a camel in Jerusalem's Old City during Christmas celebrations, on December 23, 2021. (Photo by Ahmad Gharabli/AFP Photo)

Revellers make the most of Boxing Day in Liverpool city centre, United Kingdom on Sunday, December 26, 2021. Boxing Day is a holiday celebrated after Christmas Day, occurring on the second day of Christmastide. (Photo by London News Pictures)

Navy midshipmen celebrate a Navy touchdown during the second half of an NCAA college football game, Saturday, December 14, 2019, in Philadelphia. Navy won 31-7. (Photo by Jonathan Newton/The Washington Post)

Maya Nakanishi of Japan competes en route to winning the women's T64 long jump at the World Para Athletics Championships in Dubai on November 11, 2019. (Photo by Christopher Pike/Reuters)