Governments around the world reintroduced restrictive measures as scientists raced to study a new coronavirus variant and several cases were spotted in Europe days after it was first detected in southern Africa.
Omicron, a new variant first detected in Botswana, sent Europe into high alert after cases were detected in the United Kingdom, Germany, Italy and Belgium. The Czech Republic, Austria, Israel and the Netherlands were all investigating suspected cases of the variant.
Relatively little is known about Omicron. It has mutations that scientists fear could make it more infectious and less susceptible to vaccines — though neither of these effects is yet to be established. Most confirmed cases of the variant are contained to southern African countries, but there are worries the virus could have spread more widely before scientists there discovered it.
“There’s been a window of probably about two weeks conservatively that this virus has been spreading,” Andrew Pekosz, an epidemiologist from Johns Hopkins Bloomberg School of Public Health said in an interview on Saturday. It is likely the variant is already in New York, he said.
“There certainly is a chance that it has already spread globally, but we just don’t know yet,” Mr. Pekosz added.
European leaders, already struggling with a surge in Covid-19 cases that has made it once again the epicenter of the pandemic, tried to strike a balance between increasing caution and avoiding panic.
Sixty-one passengers out of more than 500 on two flights from southern African countries into the Netherlands on Saturday tested positive for the coronavirus and are quarantining in Amsterdam. The Omicron variant is likely to be found in some of those 61 passengers who tested positive, the Dutch authorities said.
The European Union is restricting travel to and from seven countries in southern Africa, Botswana, Eswatini, Lesotho, Mozambique, Namibia, South Africa and Zimbabwe, while the United States and South Korea have targeted those countries and Malawi. Britain initially restricted travel from those eight nations before adding Angola, Malawi, Mozambique and Zambia to its red list.
Canada, Australia, Russia, Thailand, Sri Lanka, Singapore, Saudi Arabia, Oman and Morocco have all announced similar restrictions.
Israel said Saturday it would close its borders to foreign nationals for two weeks.
In a news conference on Saturday evening, Prime Minister Boris Johnson said that to curb the spread of the variant, face masks would be required in stores and on public transportation, a rule the country had ended in July.
Britain will also require travelers from abroad to get a PCR test within 48 hours of their arrival and require contacts of those who test positive with a suspected case of Omicron to self-isolate for 10 days, regardless of vaccination status.
The variant was also detected in Hong Kong, which prompted “the most stringent boarding and quarantine requirements” for travelers coming from southern African countries.
“I think certainly caution is warranted to restrict travel and to watch this closely, but at the end of the day, we really need a lot more data to evaluate this new variant,” Philip A. Chan, an infectious disease doctor at Brown University who has helped lead the Covid-19 response for Rhode Island, said.
What we do know, he said, is that the Omicron variant seems to be overtaking the Delta variant in southern African countries, which suggest Omicron is more contagious and that it can overcome some of the natural immunity and vaccine immunity.
“Neither one of those things are good, obviously. And I think that those are the two reasons that have experts and scientists so concerned,” Dr. Chan said. But he still “urges caution and patience.”
“Let’s wait to see what the data shows. Let’s take appropriate precautions,” he said.
Dr. Chan also cautioned that without a robust global vaccination effort, “we are half-treating the pandemic” and leaving the world open to new and more transmittable variants.
As more countries placed travel bans on southern Africa early Saturday for fear of a new and possibly more dangerous variant of the coronavirus, the passengers on two flights from South Africa found themselves caught in a pandemic nightmare.
After about 30 hours squeezed together in the planes, crammed buses and then in waiting rooms, 61 of the more than 500 passengers on those flights had tested positive and been quarantined. They were being checked for Omicron, named by the World Health Organization just on Friday as a “variant of concern,” its most serious category.
Everyone else, according to Stephanie Nolen, The New York Times’s global health reporter, who was on one of the planes, “has scattered to the world.”
The chaos in Amsterdam seemed emblematic of the varied, and often scattershot, responses to the virus across the world, with masking rules, national testing requirements and vaccine mandates differing from country to country and continent to continent. (KLM, the airline operating the flights, said that only some passengers had to show proof of a recent negative test, depending on vaccination status and the requirements of their final destination.)
Such gaps could open avenues for contagion, especially for a potentially threatening new variant.
“That number of people seems like a very high number to have this happen,” said Andrew Pekosz, an epidemiologist from Johns Hopkins University’s Bloomberg School of Public Health. “Unless there’s really tremendous amounts of spread of this virus locally that was not detected.”
The Omicron variant is likely to be found in some of those 61 passengers who tested positive, Dutch public health officials announced on Saturday. The sequencing is still being performed by the Dutch agency for disease control and prevention. It was unclear how many passengers may have tested positive for the variant.
Those who tested positive for the coronavirus at Amsterdam’s Schiphol Airport on Friday have been transferred to quarantine hotels. Those who tested negative could continue their journey or, if the Netherlands was their final destination, were told to quarantine at home.
The government is also telling thousands of people who have returned from southern Africa in the last few days to get tested, even if they don’t have symptoms.
There is still relatively little known about Omicron. It has mutations that scientists fear could make it more infectious and less susceptible to vaccines — though neither of these effects is yet to be established.
The numbers of confirmed cases outside southern Africa remain small, but there are worries the virus could have spread more widely before scientists there discovered it.
“It would be irresponsible” not to be worried about the new variant, Roberto Speranza, the health minister of Italy, the first European Union nation to block flights from southern Africa, told the Corriere della Sera newspaper on Saturday. “It’s a new and worrying element.”
On Friday evening, Ursula von der Leyen, the president of the European Commission, the European Union’s executive arm, said on Twitter that she held “fruitful” conversations with the pharmaceutical companies and that they “explained their efforts to quickly and thoroughly understand the Omicron variant and adjust our strategies accordingly. Time is of the essence.”
The union acted with rare unity in response to the threat posed by the new variant, binding together to restrict travel to and from southern Africa.
Vivian Loonela, a spokeswoman for the commission, said Saturday that “member states agreed to introduce rapidly restrictions on all travel into the E.U. from seven countries in the southern Africa region — Botswana, Eswatini, Lesotho, Mozambique, Namibia, South Africa, Zimbabwe.”
Mr. Speranza, Italy’s health minister, told Corriere della Sera that he considered it wise “to activate the emergency brake,” adding, the “European coordination on these decisions is fundamental.”
One of Mr. Speranza’s main criticisms during the first wave of the virus back in 2020 was that Italy was left alone, and that France and Britain and other countries did not act to ban flights from China as Italy did in January of that year.
He said the strategy of the government, to promote vaccinations through a strict health pass that was required to work and participate in much of society, would not change. The government’s message remained the same, vaccines — and now boosters — were the only way out of the pandemic.
Isabella Grullón Paz contributed reporting.
As the world scrambled to prevent the spread of the new Omicron coronavirus variant that was first detected in southern Africa, Britain’s Health Security Agency confirmed on Saturday that two cases of the variant had been recorded in the country.
In a news conference on Saturday evening, Prime Minister Boris Johnson said that to curb the spread of the variant, face masks would be required in stores and on public transportation, a rule the country had ended in July.
“As always, I must stress this, with a new variant there are many things we just cannot know at this early stage,” Mr. Johnson said.
“It does appear that Omicron spreads very rapidly and can be spread between people who are double vaccinated,” he added. Although the science around Omicron is still new, it is a “very extensive mutation” of previous configurations of the virus that could reduce vaccine effectiveness, Mr. Johnson said.
The cases are said to be linked to travel in southern Africa, the British government confirmed in a statement. Sajid Javid, Britain’s health secretary, described the new cases as a “stark reminder” that the pandemic was not yet over.
“Thanks to our world-class genomic sequencing, we have been made aware of two U.K. cases of the Omicron variant,” Mr. Javid said. “We have moved rapidly, and the individuals are self-isolating while contact tracing is ongoing.”
The country’s health agency is now carrying out targeted testing at several locations where infections could have been spread. Britain will also require travelers from abroad to get a PCR test within 48 hours of their arrival and require contacts of those who test positive with a suspected case of Omicron to self-isolate for 10 days, regardless of vaccination status.
“We don’t yet exactly know how effective our vaccines will be against Omicron, but we have good reasons for believing they will provide at least some measure of protection,” he said.
In addition to the six countries in southern Africa that were added to Britain’s travel ban list on Friday to prevent the spread of the Omicron variant, four other countries — Angola, Malawi, Mozambique and Zambia — were also added. Being on the list requires travelers to quarantine in a government-approved hotel for 10 days.
When the World Health Organization began to name the emerging variants of the coronavirus, officials turned to the Greek alphabet to make it easier for the public to understand the evolution: Alpha, Beta, Gamma, Delta and so on.
Now the alphabet has created its own political headache. When it came time to name the potentially dangerous new mutation that has emerged in southern Africa, after several variants that had proved less potent than Delta, the next letter in alphabetical order was Nu, which officials thought would be too easily confused with “new.”
The letter after that was even more complicated: Xi, a name that in its transliteration, though not its pronunciation, happens to belong to the leader of China, Xi Jinping. So they skipped both and named the new variant Omicron.
“‘Nu’ is too easily confounded with ‘new,’ and ‘Xi’ was not used because it is a common last name,” a spokesman, Tarik Jasarevic, said on Saturday in an emailed response to questions about skipping the two letters.
The organization’s policy, he went on, requires “avoiding causing offense to any cultural, social, national, regional, professional, or ethnic groups.”
The organization did not initially explain why it jumped from Mu, a lesser variant first documented in Colombia, to Omicron. The omission resulted in speculation over the reasons. For some, it rekindled criticism that the organization has been far too deferential in its dealings with the Chinese government.
“If the WHO is this scared of the Chinese Communist Party, how can they be trusted to call them out the next time they’re trying to cover up a catastrophic global pandemic?” Senator Ted Cruz, the Republican from Texas, wrote on Twitter.
There is no evidence that the Chinese had any say in naming the new strain, known scientifically as the SARS-CoV-2 variant B.1.1.529. Some variants have proved less transmissible, but Omicron could be the most worrisome new strain since the Delta variant.
Throughout the pandemic, the W.H.O. has sought to avoid the once common practice of referring to health threats with geographic terms: Spanish flu, West Nile virus, Middle East Respiratory Syndrome, Zika and Ebola.
That reflected concerns among scientists about the risk of stigmatizing places or peoples, but it was also seen in the early months of the pandemic as deferential to China, which has an influential role in global health affairs.
Chinese officials have reacted angrily to efforts to associate the pandemic with the country or Wuhan, the central city where it first spread in the fall of 2019. China’s fiercest critics in the United States, including then President Donald J. Trump and his aides, persisted anyway, at times using sophomoric and racist slurs.
“The novel coronavirus affects everyone and needs to be tackled with joint efforts, instead of fear-mongering in a xenophobic way,” Geng Shuang, a spokesman for China’s Ministry of Foreign Affairs, said at the time.
GENEVA — With coronavirus infections soaring in Switzerland, voters will deliver a verdict on their government’s health strategy on Sunday, after weeks of rancorous debate that revealed a strong current of anger in the nation’s usually placid politics.
As has happened across Europe, new Covid-19 cases have climbed steadily in Switzerland since mid-October. In the week ending Nov. 21, they jumped more than 50 percent from the week before. And the continent was put on alert over the weekend with confirmed reports of the Omicron variant in several countries.
Voters will decide whether to keep a law that requires people to show a certificate, or “green pass,” as proof of vaccination or recovery from Covid to get into restaurants, museums and other public spaces. The law also opened up billions of dollars of financial support for businesses struggling to survive the pandemic.
Health Minister Alain Berset took pains this week to say the government was not planning any more nationwide restrictions, let alone the sort of lockdown that Austria imposed this week. He cited the lack of pressure on Swiss hospitals: Official figures show that Covid patients occupy less than a quarter of I.C.U. beds and account for only about 4 percent of total hospital occupancy.
But many Swiss suspect that a tightening of controls may be unavoidable and could come as soon as Sunday’s vote is out of the way.
“We are only two weeks behind Austria, and in two weeks’ time we could be in the same situation Austria is in today,” said Pascal Sciarini, a political scientist at the University of Geneva.
In a letter reported in Swiss newspapers this week, President Guy Parmelin described the situation as “critical” and urged officials in Switzerland’s cantons, or provinces, to increase hospital capacity and mobilize specialists in preparation for a sudden deterioration in conditions.
Mr. Parmelin said the government was calling for a cantonal response partly out of concern that nationwide measures would gain lukewarm compliance in areas with low infection rates and deepen the divide between vaccinated and unvaccinated people. Unusually aggressive rhetoric and vitriol ahead of Sunday’s vote underscored those strains.
The vote is the second in four months called by a coalition of groups from across the political spectrum, but with support from the right-wing Swiss People’s Party and a strong base in the country’s mountainous, rural heartland.
“The worst thing is the ‘green pass,’ which divides the society and leads to an inhuman discrimination against two million Swiss people” who are unvaccinated, said Siegfried Hettegger, one of the managers of the campaign, which he said was not against vaccination.
Politicians who have spoken in favor of the law in televised debates have faced death threats and abuse. Campaigners against the law, including Mr. Hettegger, say opponents have destroyed their posters and campaign leaflets, hacked their websites and taken other steps to stop them from mobilizing popular support.
The first vote, held in June, delivered a 60 percent majority in favor of the law, and the latest polls suggest a similar outcome on Sunday. But the opposition campaign won a majority in eight of Switzerland’s 26 cantons in that first vote.
Any increase in the 40 percent share of the national vote the campaign achieved last time would be “a huge victory,” Mr. Hettegger said.
Asian countries with some of the world’s highest vaccination rates are rushing to expand booster shots as winter approaches and the coronavirus surges again through Europe.
After initially trailing other wealthy countries on vaccinations, several Asian nations have now overtaken them. As 2022 approaches and the new Omicron variant prompts alarm, they are calibrating their booster strategies at a time when the virus is crashing through highly vaccinated countries in Europe where boosters are not yet widely available.
The European Union’s public health agency recommended on Wednesday that all adults receive a booster shot, especially people over 40. On Thursday, its executive arm proposed that residents of the bloc will need booster shots to avoid tests or quarantines when traveling to other E.U. member states.
Dr. Tedros Adhanom Ghebreyesus, the World Health Organization’s director general, has also warned against a “false sense of security” over the protection offered by vaccines. “No country is out of the woods,” he said at a news conference on Wednesday.
Officials from highly vaccinated nations in East and Southeast Asia are well aware.
Singapore, which has one of the world’s highest Covid vaccination rates, has administered two doses to nearly nine in ten residents, according to data from the Our World in Data project at the University of Oxford. After authorizing third doses for seniors on Sept. 14 — a few days before both Britain and the United States — the city-state is now giving booster shots to people 30 and above, as well as to health care and frontline workers over age 18.
Other Asian countries are ahead of Europe in expanding access to boosters. Already, officials in Cambodia, Malaysia and Japan — countries where nearly 80 percent or more of the populations are fully vaccinated — have announced plans to give boosters to all adults.
And last week in South Korea, where nearly four in five people are fully vaccinated, the government reduced the period between second and third doses from six months to as few as four. It also expanded eligibility for shots to people 50 and over, after opening third shots to high-risk adults and those 60 and over in late October.
Kwon Jun-wook, director of the country’s National Institute of Health, has said that South Korea weighed Europe’s situation in considering its own vaccine strategy.
“In those countries, the first wave of infections after countries began reopening were mostly among the unvaccinated,” he told reporters last week. “Then infections gradually expanded to the group with waning immunity after getting vaccinated. Now we are seeing countries in Europe and, needless to say, the United States, struggle very hard to return to normalcy.”
While studies have shown that the effectiveness of vaccines can wane over time, the need for boosters has been the subject of intense debate.
Critics say that wealthy nations must stop hoarding doses. Earlier this month, Dr. Tedros described the global disparity in Covid vaccine access “a scandal that must stop now,” noting that six times more booster shots were being administered globally than primary doses in low-income countries.
JOHANNESBURG — As the United States and European countries close their borders over fears over the recently detected coronavirus variant, many South Africans say they feel as if they are being “punished” for alerting global health authorities.
Hours after South African scientists announced the existence of a new variant that they said displayed “a big jump in evolution,” Britain banned travelers from southern African nations. Other European nations and the United States quickly followed suit.
“I do apologize that people took a very radical decision,” said Tulio de Oliveira, director of the KwaZulu-Natal Research and Innovation Sequencing Platform and the scientist who announced the new variant on Thursday.
Fresh from a virtual meeting with global health leaders, including Dr. Anthony S. Fauci, President Biden’s top medical adviser on the coronavirus, Mr. Oliveira told journalists he believed that international solidarity would be in favor of South Africa’s decision to publicize its findings.
The variant, named Omicron by the World Health Organization, was first detected in South Africa and in neighboring Botswana. The government in Botswana announced that four initial cases were all foreign diplomats who had since left, and that contact tracing was continuing.
Cases have also now been spotted in Belgium, Hong Kong and Israel, in travelers sometimes returning from countries other than South Africa or Botswana, and suspected cases are being investigated in Germany and the Czech Republic.
The economies of South Africa and Botswana are reliant on tourists from the United States, Europe and China. South Africa’s tourism minister, Lindiwe Sisulu, described the temporary travel bans as “devastating.” Earlier this year, South African diplomats and scientists lobbied the British government to lift a previous ban that had already crippled tourism.
“We had been on the British red list and we worked our way out of it and with no notification we find ourselves back on the red list,” Ms. Sisulu told a national television station.
“Perhaps our scientists’ ability to trace some of these variants has been our biggest weakness,” Ms. Sisulu said. “We’re finding ourselves punished for the work that we do.”
Health officials in Africa suggested that increased screening at points of entry, or even longer quarantine periods, would have been a better alternative.
“This will just discourage different countries for sharing information which might be very important for global public health,” said Thierno Balde, incident manager for the Covid-19 emergency response for the World Health Organization’s regional office in Africa.
South Africa’s transparency was criticized by some local officials and businesspeople. Geordin Hill-Lewis, the mayor of Cape Town, said South African officials should have consulted their “travel partners” before making the announcement.
In January 2020, before global travel restrictions over the coronavirus pandemic, 93,315 international tourists arrived at Cape Town International airport, according to Statistics South Africa. By May 2021, that number had dropped to 4,821.
After the travel restrictions imposed after the highly transmissible Delta variant, Mr. Hill-Lewis said he believed that South African authorities should have expected the restrictions.
“That should have been foreseen and some heavy diplomacy put into action,” he said.
But Craig Lucke, a Cape Town-based guide who operates tours in Namibia, Botswana and South Africa called the countries’ actions “a total shocker.”
Scientific experts at the World Health Organization warned on Friday that a new coronavirus variant discovered in southern Africa was a “variant of concern,” the most serious category the agency uses for such tracking.
The designation, announced after an emergency meeting of the health body, is reserved for dangerous variants that may spread quickly, cause severe disease or decrease the effectiveness of vaccines or treatments. The last coronavirus variant to receive this label was Delta, which took off this summer and now accounts for virtually all Covid cases in the United States.
The W.H.O. said the new version, named Omicron, carries a number of genetic mutations that may allow it to spread quickly, perhaps even among the vaccinated.
Independent scientists agreed that Omicron warranted urgent attention, but also pointed out that it would take more research to determine the extent of the threat. Although some variants of concern, like Delta, have lived up to initial worries, others have had a limited impact.
William Hanage, an epidemiologist at the Harvard T.H. Chan School of Public Health and other researchers said that vaccines will most likely protect against Omicron, but further studies are needed to determine how much of the shots’ effectiveness may be reduced.
As the coronavirus replicates inside people, new mutations constantly arise. Most provide the virus with no new advantage. When worrisome mutations do emerge, the World Health Organization uses Greek letters to name the variants. The first “variant of concern,” Alpha, appeared in Britain in late 2020, soon followed by Beta in South Africa.
Omicron first came to light in Botswana, where researchers at the Botswana Harvard H.I.V. Reference Laboratory in Gaborone sequenced the genes of coronaviruses from positive test samples. They found some samples sharing about 50 mutations not found in such a combination before. So far, six people have tested positive for Omicron in Botswana, according to an international database of variants.
Around the same time, researchers in South Africa stumbled across Omicron in a cluster of cases in the province of Gauteng. As of Friday, they have listed 58 Omicron samples on the variant database. But at a news conference on Thursday, Tulio de Oliveira, the director of the Centre for Epidemic Response & Innovation in South Africa, said that “close to two or three hundred” genetic sequences of Omicron cases would be released in the next few days.
As global concern rose on Friday about a new coronavirus variant, Gov. Kathy Hochul declared a state of emergency in New York, giving her the power to order hospitals to limit nonessential procedures to boost capacity in facilities.
The new variant, called Omicron, has officially been named a “variant of concern” by the World Health Organization. The designation means that the variant has mutations that might make it more contagious or more virulent, or make vaccines and other preventive measures less effective — though none of those effects has yet been established.
The new measures in New York — which saw thousands of deaths from Covid-19 in 2020 — will take effect on Dec. 3, and are a far cry from the strict, society-wide restrictions which accompanied the early stages of the pandemic.
Still, the quick action by Ms. Hochul suggests the high level of concern not just about rising numbers of new cases across the state in recent weeks, but about the Omicron variant, which has already prompted several countries, including the United States, to restrict travelers from southern Africa.
“We continue to see warning signs of spikes this upcoming winter, and while the new Omicron variant has yet to be detected in New York State, it’s coming,” Ms. Hochul, a Democrat, said in a statement, adding that vaccination remained a critical tool in fighting the virus.
Rates of positive tests in New York have crept up recently, even as vaccination rates have improved, with some counties recording positivity rates of more than 10 percent. In the two weeks before Thanksgiving Day, the daily average of new cases reported in New York rose 37 percent, to 6,666, according to a New York Times database. More than 56,000 people have died of the disease in New York.