A health worker applies a dose of the AstraZeneca vaccine during the first day of a three-day COVID-19 vaccination campaign for people over age 35 in the Complexo da Maré favela of Rio de Janeiro, Brazil, Brazil, Thursday, July 29, 2021. Some recipients will be monitored to study the rate of protection the vaccines provide and the extent to which virus variants are circulating. (Photo by Bruna Prado/AP Photo)

A woman walks past the barbed wire separating Belarusian servicemen and Belarusian opposition supporters during a rally in Minsk, Belarus, Sunday, August 30, 2020. Tens of thousands of demonstrators have gathered in the capital of Belarus, beginning the fourth week of daily protests demanding that the country's authoritarian president resign. The protests began after an Aug. 9 presidential election that protesters say was rigged and officials say gave President Alexander Lukashenko a sixth term in office. (Photo by Tut.By via AP Photo)

Bar Convent employee Lauren Masterman relaxes after cleaning a historic George and Arthur Maw tiled floor created in 1867, one of only two surviving examples of this assemblage of tiles, at England's oldest living convent Bar Convent on October 13, 2020. Visitors to the convent are being invited to follow in the footsteps of residents from the last 150 years and enjoy the historic space decorated with rare 19th century floor tiles. (Photo by Danny Lawson/PA Images via Getty Images)

A stroller walks his dogs in an autumnally colored forest in Cuxhaven, nothern Germany on November 7, 2018. (Photo by Patrik Stollarz/AFP Photo)

Two friends attempt to balance in the icy conditions in Newcastle, England on February 2, 2019. Boozy Brits across the UK took to the streets last night to ensure they got February off to a wet start after “Dry January”. (Photo by Craig Connor/North News and Pictures)

A man sits on his cart which he attached with National League for Democracy (NLD) party flags along a flooded street in Yangon September 30, 2015. Myanmar will hold a general election on November 8. (Photo by Soe Zeya Tun/Reuters)

A Santa Claus puppet holding a Christmas tree is pictured against the sun in Berlin November 23, 2014. (Photo by Hannibal Hanschke/Reuters)

“Don't Leave Any Food On Your Plate”. The giraffes at Nairobi's Giraffe Manor are totally at home with humans. They will eat out of your hand, or even off your plate. Photo location: Giraffe Manor, Nairobi, Kenya. (Photo and caption by Gavin Werbeloff/National Geographic Photo Contest)