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)

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)

A woman holds her dogs during a snow flurry as temperatures dropped below freezing during the third coronavirus lockdown in London, Tuesday, February 9, 2021. (Photo by Kirsty Wigglesworth/AP Photo)

The Etam models perform on catwalk during ETAM Show at Flagship Hausmann near Opera in Paris, France on September 29, 2020. (Photo by J.P. Pariente/SIPA Press)

An armed police officer checks the documents of a cyclist at a checkpoint placed to implement a curfew in the country's capital amid rising coronavirus disease (COVID-19) cases, in Caloocan City, Metro Manila, Philippines, March 16, 2021. (Photo by Eloisa Lopez/Reuters)

A woman wearing a protective face mask carries her pet cat in a backpack as they wait to cross a street, amid the coronavirus disease (COVID-19) outbreak in Barcelona, Spain on April 9, 2021. (Photo by Nacho Doce/Reuters)

A hyena stands chained to its handler at a circus in Gabasawa, Kano State, Nigeria, July 27, 2021. Hyenas are often viewed as repulsive and sinister, partly due to their scavenging habits in the wild, but in northern Nigeria some men keep the creatures in their homes, display them at festivals and even use their dung to make remedies. (Photo by Afolabi Sotunde/Reuters)

Orphaned mountain gorilla, Ndakasi, lies in the arms of her caregiver, Andre Bauma, on September 21, 2021 shortly before her death, which the park confirmed on September 26. Mr Bauma and others at the Senkwekwe Mountain Gorilla Center had cared for Ndakasi and other orphans for 13 years. Ndakasi had suffered a prolonged illness prior to her death. This is the only mountain gorilla orphanage in the world and takes in mountain gorilla orphans who have lost their families to poaching or conflict. A number of the orphans here were rescued from sales by poachers in sting operations carried out by Congolese National Park Authority (ICCN) rangers. (Photo by Brent Stirton/Getty Images)