In this April 14, 2014 file photo, Hamamatou Harouna, 10, who lost the use of her legs to polio, crawls to the restroom on the grounds of the Catholic Church where she and hundreds of others found refuge after fleeing violence in her village, in Carnot, Central African Republic. Health authorities on Tuesday, August 25, 2020 are expected to declare the African continent free of the wild poliovirus after decades of effort, though cases of vaccine-derived polio are still sparking outbreaks of the paralyzing disease in more than a dozen countries. (Photo by Jerome Delay/AP Photo/File)

Young women dance a group dance at the Palace Square in St.Petersburg, Russia, Thursday, September 24, 2020. (Photo by Dmitri Lovetsky/AP Photo)

Medical staff in Belgrade, Serbia on February 5, 2021. Vaccination of employees in the city's social protection institutions has begun at the Belgrade Fair, who have expressed interest in receiving the Russian Sputnik V vaccine, and according to the city secretary for social protection Natasa Stanisavljevic, about 150 employees in those institutions will receive the vaccine today and tomorrow. (Photo by Zoran Zestic/Tanjug)

Jaida Zuniga #5 returns a volley against Northview during a girls volleyball match on grass as part of the newly formed Grass Valley League at Northview High School in West Covina on Thursday, March 4, 2021. South Hills defeated Northview (21-25), 25-13, 25-9, 25-12. (Photo by Keith Birmingham, Pasadena Star-News/SCNG)

A Syrian Democratic Forces (SDF) female fighter's braid is pictured while she is carrying her weapon in Tal Samin village, north of Raqqa city, Syria November 19, 2016. (Photo by Rodi Said/Reuters)

James Brady and a police officer are seen lying on the ground after being shot while the suspect John Hinckley Jr. is apprehended,at right, moments after the attempted assassination of President Ronald Reagan, Washington, DC, March 30, 1981. (Photo by Dirck Halstead/Getty Images)

A man prepares cookies at a small traditional factory for the Eid al-Adha, amid the spread of the coronavirus disease (COVID-19), in Kabul, Afghanistan on July 29, 2020. (Photo by Mohammad Ismail/Reuters)

A woman from the Turkana tribe waits at a shop at the village of Lorengippi near the town of Lodwar, Turkana county, Kenya, July 3, 2020. (Photo by Baz Ratner/Reuters)