Guards wait for the start of former Egyptian President Hosni Mubarak's funeral at Field Marshal Mohammed Hussein Tantawi Mosque east of Cairo, Egypt on February 26, 2020. (Photo by Amr Abdallah Dalsh/Reuters)

Protesters clash with police at Speakers Corner as thousands attend Unite For Freedom Against COVID-19 passports and vaccines in London, UK on April 24, 2021. People called online to a flash mob-style mass gathering against vaccine passport, face masks and lockdown. The government aims to provide official proof of vaccination for millions of British holidaymakers this summer starting as early as 17 May. (Photo by World Entertainment News Network)

Members of the special operations team conduct a building climbing training in Qinzhou, south China's Guangxi Zhuang Autonomous Region, April 13, 2021. (Photo credit should read Costfoto/Barcroft Media via Getty Images)

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)

A Romanian honor guard soldier stands still as three military aircraft carriers are crossing the sky during a ceremony held at the Unknown Soldier Memorial, in Carol I Park, on the occasion of the Heroes' Day commemoration, in Bucharest, Romania, 10 June 2021. (Photo by Robert Ghement/EPA/EFE)

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)

A man walks pat sculptures with face masks on along an alley in Beijing on August 3, 2021. (Photo by Noel Celis/AFP Photo)

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)