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 tourist poses for a souvenir snap in front of autumn foliage in Pitlochry, Scotland, Britain on September 28, 2018. (Photo by Russell Cheyne/Reuters)

A woman takes pictures using her mobile phone on a deserted square decorated ahead of Christmas, in Pristina on December 7, 2020, during a government-imposed curfew from 7pm to 5am, as part of preventive measures against the spread of the Covid-19. (Photo by Armend Nimani/AFP Photo)

A woman waits to hear about her sister, a teacher, following a shooting at the Sandy Hook Elementary School in Newtown, Connecticut. A man killed his mother at their home and then opened fire inside the elementary school where she taught, massacring 26 people, including 20 children, as youngsters cowered in fear to the sound of gunshots reverberating through the building and screams echoing over the intercom. (Photo by Jessica Hill/Associated Press)

A roadside currency exchange vendor sorts Indian currency notes at his stall in Agartala, India, December 6, 2016. (Photo by Jayanta Dey/Reuters)

Dog puppy “Sandy” protects against the rain with an umbrella fixed on her leash during a stroll in Rust, southern Germany, on May 26, 2013. (Photo by Patrick Seeger/AFP Photo)

A Tibetan rider fires his weapon as he perfoms his riding skills at the Qinghai Yushu Horse Racing Festival on July 27, 2007 in Yushu County of Yushu Tibetan Autonomous Prefecture, Qinghai Province, northwest China. The Horse Racing Festival of Tibetan nomads in Yushu Prefecture falls in late July and early August on the Tibetan calendar. During the festival, various equestrian skills will be performed along with singing, dancing and costume shows. (Photo by China Photos/Getty Images)

A drone operated by paramilitary police flies over the site of last week's explosions at Binhai new district in Tianjin, China, August 17, 2015. Many operations have resumed at China's Tianjin port, trade sources said, after explosions last week that killed more than 100 people and disrupted business at what is an important oil, gas and bulk import harbor for Asia's biggest economy. The explosions on August 12 led to the disruption of all chemical and oil tanker discharges at the port, and imports of iron ore were also affected. (Photo by Kim Kyung-Hoon/Reuters)