Passengers briefly disembark the MSC Europa cruise ship after docking to South African waters, as the new coronavirus variant Omicron spreads, in Cape Town, South Africa, November 30, 2021.

Barber Shane Brown wears a mask as he cuts the hair of customer Ray Richardson, as the spread of coronavirus disease (COVID-19) continues in Peterlee, Britain, November 30, 2021.

Women walk on a dirt road while carrying firewood on their heads, as the new coronavirus variant, Omicron spreads, in Qumanco village in the eastern cape province of South Africa, November 30, 2021.

People disinfect their hands while a thermal camera reads their temperature, at the entrance of a department store, on the first day of Japan's closed borders to prevent the spread of the Omicron variant of coronavirus, in Tokyo, Japan November 30, 2021. Image used for illustrative purpose.

Gulls are seen as the Europa passenger liner arrives to South African waters, as the new coronavirus variant Omicron spreads, in Cape Town, South Africa, November 30, 2021.

Britain's Health Secretary Sajid Javid speaks with staff as he visits the vaccine centre at Guy's and St Thomas Hospital amid Omicron coronavirus variant concerns in London, Britain November 29, 2021. Rick Findler/Pool via REUTERS

A nurse prepares a dose of the coronavirus disease (COVID-19) vaccine as the new Omicron variant spreads, in Dutywa, in the Eastern Cape province, South Africa November 29, 2021. Image used for illustrative purpose.

Top U.S. infectious disease official Dr. Anthony Fauci and U.S. President Joe Biden deliver an update on the Omicron variant at the White House in Washington, U.S., November 29, 2021.

Tourists show their vaccination certificate as they visit Khaosan Road, one of the favourite tourist spots, as Thailand bans entry from eight African countries over the coronavirus Omicron variant, in Bangkok, Thailand, November 30, 2021.

Tourists visit the Reclining Buddha at Wat Phra Chetuphon (Wat Pho), one of the favourite tourist spots as Thailand bans entry from eight African countries due to the new Omicron variant of the coronavirus in Bangkok, Thailand, November 30, 2021.

A passenger wearing a protective mask and face shield makes his way to his flight at a terminal of Narita international airport on the first day of closed borders to prevent the spread of the new coronavirus Omicron variant amid the coronavirus disease (COVID-19) pandemic in Narita, east of Tokyo, Japan, November 30, 2021.

A notice about COVID-19 safety measures is pictured next to closed doors at a departure hall of Narita international airport on the first day of closed borders to prevent the spread of the new coronavirus Omicron variant in Narita, east of Tokyo, Japan, November 30, 2021.

Men wearing protective suits make their way at a bus stop at Narita international airport on the first day of closed borders to prevent the spread of the new coronavirus Omicron variant amid the coronavirus disease (COVID-19) pandemic in Narita, east of Tokyo, Japan, November 30, 2021. Image used for illustrative purpose.

Pick up service staffs wait for passengers at an arrival hall at Narita international airport on the first day of closed borders to prevent the spread of the new coronavirus Omicron variant amid the coronavirus disease (COVID-19) pandemic in Narita, east of Tokyo, Japan, November 30, 2021.

Students apply finishing touches to paintings made to create an awareness against the new coronavirus Omicron variant, in Mumbai, India, November 29, 2021.

A traveller receives a test for the coronavirus disease (COVID-19) at a pre-departure testing facility, as countries react to the new coronavirus Omicron variant, outside the international terminal at Sydney Airport in Sydney, Australia, November 29, 2021. Image used for illustrative purpose.

A passenger arrives at a terminal of Ronald Reagan Washington National Airport as countries react to the new coronavirus Omicron variant amid the coronavirus disease (COVID-19) pandemic, in Washington, U.S. November 30, 2021. Image used for illustrative purpose.

A tourist visits Wat Phra Chetuphon (Wat Pho), one of the favourite tourist spots as Thailand bans entry from eight African countries due to the new Omicron variant of the coronavirus in Bangkok, Thailand, November 30, 2021.