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 man walks pat sculptures with face masks on along an alley in Beijing on August 3, 2021. (Photo by Noel Celis/AFP Photo)

A couple pours water on their dogs during a hot day, in Rome, Thursday, August 12, 2021. In Italy, 15 cities received warnings from the health ministry about high temperatures and humidity with peaks predicted for Friday. The cities included Rome, Florence and Palermo, but also Bolzano, which is usually a refreshing hot-weather escape in the Alps. (Photo by Andrew Medichini/AP Photo)

Olympic medal winning twins Jessica (left) and Jennifer Gadirova celebrate their GCSE results at Aylesbury Vale Academy in Buckinghamshire, United Kingdom onThursday, August 12, 2021. (Photo by Steve Parsons/PA Images via Getty Images)

A local resident performs traditional horse racing during a celebration marking the 70th anniversary of the founding of Yushu Tibetan Autonomous Prefecture, in northwest China's Qinghai Province, August 4, 2021. (Photo by Xinhua News Agency/Rex Features/Shutterstock)

Wounded women arrive at a hospital for treatment after two blasts, which killed at least five and wounded a dozen, outside the airport in Kabul on August 26, 2021. (Photo by Wakil Kohsar/AFP Photo)

American singer and rapper Ashton Nicole Casey, known professionally as Ashnikko performs on Day 2 of Leeds Festival 2021 at Bramham Park on August 28, 2021 in Leeds, England. (Photo by Matthew Baker/Getty Images)

A Taliban fighter walks past a beauty salon with images of women defaced using spray paint in Shar-e-Naw in Kabul on August 18, 2021. (Photo by Wakil Kohsar/AFP Photo)