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)

Ivanelis Jimenez, front, and Veronica Barreto pose for the camera wearing Puerto Rican flag dresses as they welcome passengers exiting Carnival's Mardi Gras cruise ship, docked in the bay of San Juan, Puerto Rico, Tuesday, August 3, 2021, marking the first time a cruise ship visits the U.S. territory since the COVID-19 pandemic began. (Photo by Carlos Giusti/AP Photo)

Students wearing masks as a precaution amid the spread of COVID-19 put away a Cuban flag so it does not get wet in the rain on their first day of school after months without face-to-face classes in Havana, Cuba, Monday, November 8, 2021. As Cuba approaches the announced date of Nov. 15 for the reopening of the entire country to the world, getting children back to school is one of its priorities. (Photo by Ramon Espinosa/AP Photo)

A pedestrian wearing a face mask to protect against coronavirus, walks in front of a mural, at a metro station in Athens, Greece, Monday, November 15, 2021. Authorities say the rate of death related to COVID-19 in Greece has reached its highest level in six months as roughly one-third of the country's population remains unvaccinated. (Photo by Thanassis Stavrakis/AP Photo)

Ayaka Oshita, a 27-year-old diver, practices in preparation for the upcoming seasonal feeding performance as a Santa diver at Sunshine Aquarium at Ikebukuro in Tokyo, Japan, 07 December 2021. Oshita has 15-month experience for feeding fish at the aquarium after she joined the aquarium in 2019. The Santa diver performance will be held for three days around the Christmas time. The aquarium will not inform the performance time to avoid the visitors' crowd due to the COVID-19 pandemic. (Photo by Kimimasa Mayama/EPA/EFE)

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)

An employee of cake shop prepares chocolate Easter bunnies with masks in Lykovrisi, northern Athens, on Wednesday, April 8, 2020. Cake shops and bakeries in Greece have remained open during a strict circulation ban in Greece to contain the spread of the COVID-19, but authorities have intensified a crackdown on lockdown violations ahead of Easter, which is celebrated by Orthodox Christians on April 19. Greece's Orthodox Church says it will not permit any public gatherings for Easter services. (Photo by Thanassis Stavrakis/AP Photo)

A child of a migrant worker drinks water as his mother holds him while waiting in a queue for transport to reach to a railway station to board a train to their home state of northern Uttar Pradesh, after a limited reopening of India's giant rail network following a nearly seven-week lockdown to slow the spreading of the coronavirus disease (COVID-19), in Ahmedabad, India, May 15, 2020. (Photo by Amit Dave/Reuters)