Pedestrians wear masks as smoke and haze from bushfires in New South Wales blankets the CBD in Sydney, Australia, 10 December 2019. The New South Wales environment department says visibility across east and southwest Sydney was at a “hazardous” level on Tuesday morning, while air quality was poor in southwest Sydney and hazardous in northwest Sydney. (Photo by Steven Saphore/EPA/EFE)

In this Sunday, February 23, 2020, photo, sumo wrestlers wearing masks arrive at Shin Osaka railway station in Osaka, western Japan. A viral outbreak that began in China has infected more than 79,000 people globally. The World Health Organization has named the illness COVID-19, referring to its origin late last year and the coronavirus that causes it. (Photo by Kyodo News via AP Photo)

An NHS worker walks past a banner supporting NHS staff outside Salford Royal Hospital on March 22, 2020 in Manchester, UK. Coronavirus (COVID-19) has spread to at least 182 countries, claiming over 13,069 lives and infecting more than 308,592 people. There have now been 5,018 diagnosed cases in the UK and 233 deaths. (Photo by Anthony Devlin/Getty Images)

A baby dives as his mother holds on tightly during a water baby class in Odessa, Ukraine on August 6, 2016. (Photo by Andrey Nekrasov/Barcroft Images)

This handout picture released by Jordan's Aqaba Special Economic Zone Authority (ASEZA) on July 23, 2019 shows a Jordanian Armed Forces armored vehicle lies on the seabed of the Red Sea off the coast of the southern port city of Aqaba, part of a new underwater military museum. (Photo by Aqaba Special Economic Zone Authority via Reuters)

This picture taken on June 25, 2019 shows couples wait for their turn for their pre-wedding photo shoot at the Love Story in Rome Studio in Beijing. Increasingly elaborate pre-wedding photos are a booming industry in China, as young couples spend time and cash lining up glamorous photo shoots to display on their big day. (Photo by Fred Dufour/AFP Photo)

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)