An Indian nomadic shepherd from the western Rajasthan state guides his flock of sheep through an access road in Greater Noida, outskirts of New Delhi, India, Tuesday, December 5, 2017. Looking for suitable pasture lands for grazing, shepherds migrate their flocks over extensive areas in the same state or to neighboring states in India. (Photo by R.S. Iyer/AP Photo)

North Korean cheerleaders arrive at a rest stop, or service station, as their bus convoy carrying a 280- member delegation on its way to the 2018 Pyeongchang winter Olympic games, makes its way past Gapyeong on February 7, 2018 More than 200 young North Korean women arrived in South Korea to root for athletes from both sides of the peninsula at the Winter Olympics. (Photo by Ed Jones/AFP Photo)

Model Heidi Klum in front of Concorde jet after arriving for Victoria's Secret fashion show at Cannes Film Festival on May 16, 2000. (Photo by Marion Curtis/DMI/The LIFE Picture Collection/Getty Images)

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)

Vehicles move past a man wearing a protective mask against COVID-19 as he waits for the bus in Karachi, Pakistan on December 11, 2020. (Photo by Akhtar Soomro/Reuters)

A restaurant worker wearing a mask cleans the windows as the restaurant reopens amid the COVID-19 pandemic in Sao Paulo, Brazil, Monday, July 6, 2020. Bars, restaurants and beauty salons were allowed to re-open Monday after over three months of quarantine, and are required to observe preventative measures and reduced operating hours only during the day. (Photo by Andre Penner/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)

Sikh Nihang (Sikh warriors) perform “Gatka”, an ancient form of Sikh martial arts, during the “Nagar Kirtan” procession to mark the 339th birth anniversary of the Sikh warrior Shaheed Baba Deep Singh, in Amritsar on January 31, 2021. (Photo by Narinder Nanu/AFP Photo/Profimedia)