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)

Swimmers known as the Lido Ladies pose by the pool during sunrise at Charlton Lido in Hornfair Park, London on December 2, 2020, on its first day of reopening after the second national lockdown ended and England enters a strengthened tiered system of regional coronavirus restrictions. (Photo by Victoria Jones/PA Images via Getty Images)

A pack of wild smooth-coated otters, nicknamed the “Zouk family”, crosses Penang Road in Singapore on March 3, 2021, the World Wildlife Day. The “Zouks”, a well-known otter family in Singapore, started out from the Istana on Wednesday, and made a “royal” tour of various landmarks in Singapore. (Photo by Chine Nouvelle/SIPA Press/Rex Features/Shutterstock)

Volunteers skin western diamondback rattlesnakes during the 2021 Rattlesnake Roundup at the Nolan County Coliseum in Sweetwater, Texas on March 13, 2021. The town of Sweetwater holds the largest rattlesnake roundup in the world, launched in 1958 with the sole purpose of getting rid of rattlesnakes, killing an average of 5,000 pounds of snake each year. (Photo by Paul Ratje/AFP Photo)

Women dance on top of a car as revelers enjoy spring break festivities despite an 8pm curfew imposed by local authorities, amid the coronavirus disease (COVID-19) pandemic, in Miami Beach, Florida, U.S., March 20, 2021. (Photo by Marco Bello/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 young couple rest on a bench, as a street actor wearing an Angel costume speaks on the phone in Nikolskaya street near the Kremlin in Moscow, Russia, Wednesday, March 31, 2021. (Photo by Alexander Zemlianichenko/AP Photo)