The United Kingdom, Germany and Italy have detected cases of the new Omicron coronavirus variant as British Prime Minister Boris Johnson announced new steps to contain the virus while more countries impose restrictions on travel from southern Africa.
The discovery of the variant has sparked global concern, a wave of travel bans or curbs and a sell-off on financial markets on Friday as investors worried that Omicron could stall a global recovery from the nearly two-year pandemic.
Two linked cases of the new variant detected in the UK were connected to travel to southern Africa, British health minister Sajid Javid said.
Speaking later, Johnson laid out measures that included stricter testing rules for people arriving in the country but that stopped short of curbs on social activity other than mask wearing in some settings.
"We will require anyone who enters the UK to take a PCR test by the end of the second day after their arrival and to self-isolate until they have a negative result," Johnson told a news conference.
People who had come into contact with people testing positive for a suspected case of Omicron would have to self-isolate for 10 days and the government would tighten up the rules on wearing face coverings, Johnson said, adding the steps would be reviewed in three weeks.
The health ministry in the German state of Bavaria also announced two confirmed cases of the variant.
The two people entered Germany at Munich airport on November 24 - before Germany designated South Africa as a virus-variant area - and were now isolating, said the ministry, indicating without stating explicitly that the people had travelled from South Africa.
In Italy, the National Health Institute said a case of the new variant had been detected in Milan in a person coming from Mozambique.
Czech health authorities also said they were examining a suspected case of the variant in a person who spent time in Namibia.
Still much uncertainty around Omicron
England's Chief Medical Officer, Chris Witty, said at the same news conference as Johnson that there was still much uncertainty around Omicron, but "there is a reasonable chance that at least there will be some degree of vaccine escape with this variant".
Omicron, dubbed a "variant of concern" by the World Health Organisation on Saturday, is potentially more contagious than previous variants of the disease although experts do not know yet if it will cause more or less severe COVID-19 compared to other strains.
The variant was first detected in South Africa and had also since been identified in Belgium, Botswana, Israel and Hong Kong.
Dozens of plane passengers positive for Covid-19
Dutch authorities said that 61 out of around 600 people who arrived in Amsterdam on two flights from South Africa on Friday had tested positive for the coronavirus.
Health authorities were carrying out further tests to see if those cases involved the new variant.
One passenger who arrived from South Africa on Friday, Dutch photographer Paula Zimmerman, said she tested negative but was anxious for the days to come.
"I've been told that they expect that a lot more people will test positive after five days. It's a little scary the idea that you've been in a plane with a lot of people who tested positive," she said.
It could take weeks for scientists to fully understand the variant's mutations and whether existing vaccines and treatments are effective against it.
Although epidemiologists say travel curbs may be too late to stop Omicron from circulating globally, many countries around the world - including the United States, Brazil, Canada and European Union members - announced travel bans or restrictions on southern Africa on Friday.
Omicron has emerged as many countries in Europe are already battling a surge in COVID-19 infections, and some have re-introduced restrictions on social activity to try to stop the spread.
Austria and Slovakia have entered lockdowns.
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