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)

A woman reacts as she receives the AstraZeneca/Oxford vaccine under the COVAX scheme against coronavirus disease (COVID-19) at the Kenyatta National Hospital in Nairobi, Kenya on March 5, 2021. (Photo by Monicah Mwangi/Reuters)

Two women pose as they drink real ale at the Great British Beer Festival in the Olympia exhibition centre on August 13, 2013 in London, England. The festival, which runs until August 17, 2013, has over 24 bars serving over 800 different beers, ciders and perries. (Photo by Oli Scarff)

Willow O'Brien, 5, holds an Irish flag as she poses for pictures, amid the outbreak of the coronavirus disease (COVID-19), on Saint Patrick's Day in Dublin, Ireland, March 17, 2021. (Photo by Clodagh Kilcoyne/Reuters)

Elsa, Dolly, Jeanie, Vince, Titch and Bailey savour seaside smells at Reculver Towers and Roman Fort, Kent, United Kingdom on February 23, 2021. The southeast of England will be warm again. (Photo by Liz Gregg/Triangle News)

Rapper Pitbull performs onstage during Nickelodeon's celebration of the new Burbank facility on January 11, 2017 in Los Angeles, California. (Photo by Charley Gallay/Getty Images for Nickelodeon)

Thomas jumps into the water from a spring board at a public swimming pool in Mengen, Germany, 28 August 2016. (Photo by Thomas Warnack/EPA)