A person in California has become the first in the US to have an identified case of the Covid-19 Omicron variant as scientists continue to study the risks posed by the new strain of the virus.
The US moved late last month to restrict travel from southern Africa where the variant was first identified and had been widespread. Clusters of cases have also been identified in about two dozen other nations.
"This is the first case of Covid-19 caused by the Omicron variant detected in the United States," Dr Anthony Fauci said today at the White House. He said the person was a traveller who returned from South Africa on November 22 and tested positive on November 29.
The US is now tightening rules for overseas travellers, including requiring a test for all travellers within a day of boarding a flight regardless of vaccination status. The US was also considering mandating post-arrival testing.
Officials said those measures would only "buy time" for the country to learn more about the new variant and to take appropriate precautions, but that given its transmissibility its arrival in the US was inevitable.
Much remains unknown about the new variant, including whether it is more contagious than previous strains, whether it makes people more seriously ill, and whether it can thwart the vaccine. Fauci, the top US infectious disease expert, said more would be known about the Omicron strain in two to four weeks as scientists grow and test lab samples of the virus.
The announcement of the first US case comes before President Joe Biden plans to outline his strategy on Thursday (US time) to combat the virus over the winter. Biden has tried to quell alarm over the Omicron variant, saying it was a cause for concern but "not a cause for panic".
Biden and public health officials have grown more urgent in their pleas for more Americans to get vaccinated — and for those who have been vaccinated to get booster shots to maximise their protection against the virus.
World reacts to variant spread
The new variant kept a jittery world off-kilter as Japan further tightened travel restrictions, infections linked to the new version of the coronavirus popped up in more places and new evidence made clear the mutant strain was circulating weeks earlier than thought.
Much is still unknown about Omicron, including how contagious it is and whether it can evade vaccines, and the European Union chief acknowledged that waiting for scientists to tell the world more felt like "an eternity".
Meanwhile, many nations in Europe are still dealing with a surge in infections and hospital admissions from the Delta variant.
Japan continued its aggressive stance, asking international airlines to stop taking new reservations for all flights arriving in the country until the end of December.
The move by the world's third-largest economy, coupled with its recent return to a ban on foreign visitors, is among the most severe anywhere, and more in line with cloistered neighbour China than with some other democracies in the region.
Many countries around the world, however, have barred travellers from southern Africa, and the US was moving to toughen testing requirements for international arrivals before their first confirmed case.
South African researchers alerted the World Health Organisation to Omicron last week, but it is not known where or when the variant first emerged, and it's already clear it was circulating in Europe before that alert.
Nigeria stretched the timeline back even further when its national public health institute said it detected the variant in a sample it collected in October — also its first known case of the mutation.
The worry and uncertainty about the new variant and the sometimes haphazard imposition of restrictions recalled the early days of the pandemic, as did the familiar realisation that the virus had once again outpaced efforts to contain it.
In a sign of how difficult the virus is to control in an age of jet travel and economic globalisation, Japan confirmed its second case of the variant — in a person who arrived from Peru via Qatar. Saudi Arabia, meanwhile, said Wednesday it had detected its first case of Omicron, a day after Brazil reported cases of the variant, the first known ones in Latin America.
"I listen to my scientists, they all say we do not know enough now. Therefore, it is good that they take their two to three weeks," said European Commission President Ursula von der Leyen. "This is, in normal times, a short period. In pandemic times, it's an eternity."
While the world waited impatiently for more information, some countries were already struggling to beat back surges that predated the announcement of Omicron.
Germany's intensive care association warned that the number of Covid-19 patients requiring intensive care will hit a new high before Christmas — and that it expected the all-time high from last year to be exceeded.
The DIVI association called for national restrictions to slow the spread immediately. German federal and state leaders are expected to decide on new measures. Chancellor-designate Olaf Scholz said he would back a proposal to mandate vaccinations for everybody next year.
Austria, meanwhile, extended its lockdown until December 11 as planned amid signs that the restrictions are helping to bring down a sky-high coronavirus infections.
Germany and Austria are among several nations in Europe seeing surges — even some with relatively high vaccination rates.
Portugal — with an 87 per cent vaccination rate that is among the highest globally — tightened entry requirements and mandated masks indoors to slow an upward trend. Until recently, the country was shielded from the spikes experienced by elsewhere on the continent.
South Korea is also seeing a Delta-driven surge that has pushed hospital admissions and deaths to record highs. The country on Wednesday reported a daily jump in coronavirus infections that exceeded 5000 for the first time — along with its first cases of the new variant.
The emergence of yet another variant has left the world once again whipsawed between hopes of returning to normal and fears that the worst is yet to come.
In Singapore, which is trying a strategy of living with Covid-19 and has one of the world's leading vaccine programmes, cases are now dropping rapidly, and there's cautious optimism that its widely watched plan has helped it turn a corner in the pandemic.
Fiji welcomed back its first tourists in more than 600 days on Wednesday after pushing ahead with reopening plans despite the threat posed by omicron.
Fauci, the United States' top infectious disease expert, said much more will be known about Omicron in the next several weeks, and "we'll have a much better picture of what the challenge is ahead of us". - AP