Revellers in Leeds, United Kingdom were excited to be out and about again on July 18, 2021. At a minute past midnight, England dropped most of its remaining Covid-19 social restrictions, such as those requiring indoor mask-wearing and limits on group gatherings. These changes come despite rising infections, pitting the country's vaccination programme against the virus's more contagious Delta variant. (Photo by Ioannis Alexopoulos/PA Wire Press Association via Getty Images)

Rescuers carry an injured passenger on stretcher at Soshigaya Okura Station after stabbing on a commuter train, in Tokyo Friday night, August 6, 2021. A man with a knife attacked 10 passengers on a commuter train in Tokyo on Friday and was arrested by police after fleeing, fire department officials and news reports said. (Photo by Kyodo News via AP Photo)

A bakery worker carries fresh bread in Cairo, Egypt on August 1, 2021. (Photo by Amr Abdallah Dalsh/Reuters)

A woman cools off at a fountain in central Cordoba, southern Spain, 11 August 2021. Andalucia was put on orange alert for high temperatures, with a new heatwave forecast to reach temperatures of over 41 degrees Celsius in the region. (Photo by Salas/EPA/EFE)

Hot-air balloons float over the Oka River during the Russian Sky International Balloon Festival in Ryazan Region, Russia on July 26, 2021. (Photo by Alexander Ryumin/TASS)

A lemur inspects a camera at Tarsus Nature Park in Mersin, Turkey on July 25, 2021. The population of lemurs, one of the inhabitants of Tarsus Nature Park, increases with new births every year. Lemurs are among the most interesting species in the zoo. (Photo by Serkan Avci/Anadolu Agency via Getty Images)

A giant classic Hindu Ramayana statue dons a face mask to remind passengers to keep to coronavirus precautions at the Suvarnabhumi airport in Bangkok, Thailand, Wednesday, July 21, 2021. The Civil Aviation Authority of Thailand has ordered a halt to all domestic flights operating from the most severely affected provinces effective Wednesday. Exceptions are allowed for flights to destinations that are part of a plan that allows vaccinated travelers from abroad to stay for two weeks on popular islands such as Phuket and Samui without quarantine confinement. (Photo by Sakchai Lalit/AP Photo)

English-French actress and singer-songwriter Charlotte Gainsbourg attends the red carpet of the movie “Sundown” during the 78th Venice International Film Festival on September 05, 2021 in Venice, Italy. (Photo by Ernesto Ruscio/Getty Images)