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 couple takes selfie pictures amid heart shaped decorations setted for Valentine's day, in Bangkok, Thailand on February 14, 2021. (Photo by Mladen Antonov/AFP Photo)

Members of the media document a damaged train carriage extracted from a tunnel after the deadly train derailment north of Hualien, Taiwan on April 6, 2021. (Photo by Ann Wang/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)

Children with painted faces in the art of the bahurupi tradition in Bardhaman, India on April 24, 2021. Impersonators family where their generations are engaged in making face painting and can easily metamorphose into different characters during a performance, as per different Traditional & Tribal myth which is the main earning source for their family. (Photo by Avishek Das/SOPA Images/Rex Features/Shutterstock)

Students protest in red underwear on the Plein in The Hague, The Netherlands, 02 June 2021. The action is part of the #NietMijnSchuld campaign by Dutch union FNV Young & United and the National Student Union LSVb, which are campaigning for a debt-free basic grant. (Photo by Bart Maat/EPA/EFE)

A resident reacts as a health worker collects a swab sample to test for the Covid-19 coronavirus in Colombo on July 27, 2021. (Photo by Ishara S. Kodikara/AFP Photo)

Freshmen take part in a military training at Chongqing City Vocational College on September 23, 2021 in Chongqing, China. (Photo by Chen Shichuan/VCG via Getty Images)