Two women dressed for a party take photos of each other outside a venue in London, Friday, December 17, 2021. On what would normally be one of the busiest times for pubs and restaurants just before Christmas, customer numbers are down in central London due to concerns about the new omicron variant. Friday night in Central London was muted with one bar saying they have 30 customers inside when there should have been 170, with large amounts of cancellations in recent days. (Photo by Alastair Grant/AP Photo)

A woman stands in front of a mask-clad lion statue outside a department store in Tokyo's Ginza district on January 18, 2022, as Japan reported a record high of new Covid-19 infections fuelled by the Omicron variant. (Photo by Philip Fong/AFP Photo)

Commuters wear protective face masks as they walk through a subway station, in Sao Paulo, Brazil, Wednesday, December 1, 2021, amid the COVID-19 pandemic. Brazil joined the widening circle of countries to report cases of the omicron variant. (Photo by Andre Penner/AP Photo)

Revellers enjoying the pubs and clubs in Leeds despite concerns over Omicron on December 10, 2021. Festive revellers have hit the pubs and clubs across the UK tonight as Plan B rules come into force and fears grow over the spread of Omicron. (Photo by Nb press ltd)

A couple take photographs alongside the National Monument on Calton Hill, Edinburgh on Wednesday January 5, 2022, ahead of First Minister Nicola Sturgeon's update to the Scottish Parliament on the Covid-19 situation as the Omicron variant sweeps across the country. (Photo by Jane Barlow/PA Images via Getty Images)

A woman wearing a protective mask walks through a platform of a train station during the afternoon rush hours as the Omicron variant continues to spread, amid the coronavirus disease (COVID-19) pandemic, in Jakarta, Indonesia, January 3, 2022. (Photo by Willy Kurniawan/Reuters)

Glam revellers have proudly shown off their vaccine passports as they glammed up for a night on the town on the first day of fresh Covid restrictions in Newcastle, United Kingdom on December 15, 2021. Brits donning festive gear decided to tear up nightclub dance floors and booze in pubs despite fears over the Omicron variant. (Photo by Newcastle New Projects)

A resident receives a dose of Pfizer BioNTech COVID-19 vaccine at a rural village on December 01, 2021 in Aringay, La Union province, Philippines. The Philippines is rushing to vaccinate its population as it mulls making COVID-19 vaccination mandatory and amid the looming threat of the Omicron variant of the coronavirus. The country, which has just approved booster shots for its adult population, launched a three-day national vaccination holiday on November 29 to December 1 with the goal of vaccinating at least nine million additional people. (Photo by Ezra Acayan/Getty Images)