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)

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)

Anilson Costa, reveller of the annual block party “Ceu na Terra”, walks along the Santa Teresa neighborhood where the block party used to be celebrated, as Carnival celebrations have been canceled, amid the coronavirus disease (COVID-19) pandemic, in Rio de Janeiro, Brazil on February 12, 2021. (Photo by Pilar Olivares/Reuters)

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)

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)

A grey heron is seen at the Sempione park, after Lombardy was downgraded from a red to an orange zone, loosening the coronavirus disease (COVID-19) restrictions including allowing non-essential shops to re-open, in Milan, Italy, April 13, 2021. (Photo by Flavio Lo Scalzo/Reuters)