Dutch Find Omicron in Sample From Mid-November, 5 Days Before South Africa Discovery

Dutch health authorities discovered the Omicron coronavirus variant in samples from as early as November 19, five days before the World Health Organization said that South Africa first reported the strain, the Associated Press reported.

The discovery makes even more unclear the timeline and origin of Omicron's emergence as scientists try to figure out how dangerous it might be.

Though cases of the variant don't appear to be exceptionally plentiful, infections have popped up worldwide. Japan and France reported their first Omicron cases Tuesday, joining the U.K., Germany, Australia and others that have seen the variant slip past their borders.

Some nations looking to curb new outbreaks in the lingering pandemic have rapidly enacted travel restrictions, especially for visitors coming from South Africa, AP reported. South Africa and the WHO have urged against the measures, while the discovery of earlier Omicron infections in the Netherlands casts doubt on how effective such restrictions might be when the variant's origin remains unclear.

For more reporting from the Associated Press, see below.

German authorities said they had an Omicron infection in a man who had neither been abroad nor had contact with anyone who was.

The WHO warned Monday that the global risk from Omicron is "very high" and that early evidence suggests it might be more contagious. Others sent more reassuring messages, like European Medicines Agency chief Emer Cooke, who insisted that the 27-nation European Union was well prepared for the variant. While it is not known how effective current vaccines are against Omicron, Cooke said the shots could be adapted within three or four months if need be.

But nearly two years after the virus first held the world in its grip, the current response echoed in many ways the chaos of the early days, including haphazard travel bans and a poor understanding of who was at risk and where.

Many officials tried to calm fears, insisting vaccines remain the best defense and that the world must redouble its efforts to get the shots to every part of the globe.

The latest variant makes those efforts even more important, U.S. Secretary of State Antony Blinken said, noting as many have before that "as long as the virus is replicating somewhere, it could be mutating."

In the face of the new variant, some introduced new measures aimed at mitigating the spread.

England made face coverings mandatory again on public transport and in shops, banks and hairdressers. And one month ahead of Christmas, the head of the U.K,'s Health Security Agency, Jenny Harries, urged people not to socialize if they don't need to.

And after COVID-19 already led to a one-year postponement of the Summer Games, Olympic organizers were beginning to worry about the February Winter Games in Beijing.

Chinese Foreign Ministry spokesperson Zhao Lijian said Omicron would "certainly bring some challenges in terms of prevention and control."

Japan had announced that it would ban all foreign visitors beginning Tuesday—but that turned out to be too late. It confirmed its first case that day, a Namibian diplomat who recently arrived from his country.

World markets continued to seesaw on every piece of medical news, either worrisome or reassuring.

Global shares mostly slipped Tuesday as investors cautiously weighed how much damage omicron may unleash on the global economy.

Some analysts think a serious economic downturn, like what happened last year, likely will be averted because many people have been vaccinated. But they also think a return to pre-pandemic levels of economic activity, especially in tourism, has been dramatically delayed.

In a world that is already unnerved by the more contagious delta variant that filled hospitals again in many places, even in some highly vaccinated nations, the latest developments underscored the need for the whole globe to get their hands on vaccines.

"We have vaccination rates in the United States, in Europe of 50, 60, 70 percent, depending on exactly who you're counting. And in Africa, it's more like 14, 15 percent or less," Blinken said.

"We know, we know, we know that none of us will be fully safe until everyone is."