President Biden will restrict travel from South Africa and seven other African countries to try to contain a troubling new variant of the coronavirus, senior administration officials said on Friday, though they said it would be impossible to prevent it from entering the United States.
Starting on Monday, the administration will prohibit travelers from South Africa, Botswana, Zimbabwe, Namibia, Lesotho, Eswatini, Mozambique and Malawi from coming to the United States, the officials said.
The travel ban will not apply to American citizens or lawful permanent residents, officials said. But they will need to show a negative coronavirus test before coming to the United States.
Mr. Biden made the decision after he was briefed by advisers including Dr. Anthony S. Fauci, who said in an interview Friday that the variant appeared to be spreading rapidly and that he and other health officials in the United States were consulting with South African scientists. The Centers for Disease Control and Prevention announced in a statement late Friday that no cases of the new variant had been identified in the United States.
The White House announced the decision after the World Health Organization said the newly detected version of the virus, labeled Omicron, was “a variant of concern,” a category for dangerous variants that may spread quickly, cause severe disease or decrease the effectiveness of vaccines or treatments.
“I’ve decided that we’re going to be cautious,” Mr. Biden told reporters in Nantucket. “We don’t know a lot about the variant except that it is a great concern and seems to spread rapidly.”
By imposing the travel restrictions, the administration will not stop the virus from coming to the United States. But it can give health officials and pharmaceutical companies time to determine whether the current vaccines work against the new variant — and if not, to create new vaccines that do.
“It’s going to buy us some time,” Dr. Fauci said. “It’s not going to be possible to keep this infection out of the country. The question is: Can you slow it down?”
Dr. Fauci said the new variant has about 30 mutations, and roughly 10 of them are on a part of the virus that is associated with transmissibility and immune protection. That suggests the virus may be more transmissible and may escape the current vaccines “to an extent yet to be determined.”
He said there had been some breakthrough infections among those who had recovered from the Delta variant, and among those who were vaccinated.
But at the same time, he said, scientists do not know the severity of the infections caused by the new variant. It is entirely possible that it spreads more quickly but causes less severe disease.
“You don’t want to say don’t worry, and you don’t want to say you’ve got to worry yourself sick, because we’re gathering information rapidly,” he said, adding, “Even though the numbers are still small, the doubling time is pretty rapid and the slope of the increase is really rather sharp.”
Biden administration officials said they were continuing to work with health officials in other countries to learn more about the variant.
“Restricting travel is going to slow its coming, not stop it from coming,” said Dr. Ezekiel Emanuel, chair of the department of medical ethics at the University of Pennsylvania and an adviser to the president during his transition. “The fact that it’s coming here is inevitable. The environment in which it comes may not be inevitable. We can alter the environment.”
Mr. Biden said on Friday that the rise of the Omicron variant was another reason for vaccinated Americans to get boosters and unvaccinated Americans to get inoculated — a point Dr. Fauci echoed. And Mr. Biden said the development should push the international community to donate more vaccines to nations suffering from a lack of access or poor vaccination rates.
Michael Osterholm, an infectious disease expert at the University of Minnesota who also advised Mr. Biden during his transition, said the administration had little choice on implementing the travel ban.
But Dr. Osterholm said it could take time before scientists know if the current vaccines are effective against the variant, and how transmissible it is. One way to figure that out is through laboratory studies, which will take several weeks, he said. Another way is to follow breakthrough cases in people who are already vaccinated, which could take months.
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.”
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.
The Canadian government said late Friday that it would bar travelers from seven southern African countries until the end of January, citing concerns about the emerging Omicron coronavirus variant.
The ban applies to foreign nationals who have been in the seven countries — South Africa, Eswatini, Lesotho, Botswana, Zimbabwe, Mozambique and Namibia — within two weeks of their planned arrival in Canada. There are no direct flights between Canada and the southern African region, the government said.
Canadian citizens and permanent residents who have been in the region within two weeks of returning home can still return to Canada but will face enhanced testing and quarantine protocols, regardless of their vaccination status.
The Omicron variant had not been detected in Canada as of Friday. The government described the new restrictions as a precautionary step and cited similar ones in Britain, the European Union and the United States.
“These new measures are being put in place out of an abundance of caution,” Jean-Yves Duclos, Canada’s health minister, said in a statement. “We will continue to do what is necessary to protect the health of Canadians.”
Canada has fully vaccinated 77 percent of its population, according to data from the Our World in Data project at the University of Oxford. It is averaging about seven new cases a day per 100,000 people, slightly more than South Africa but far below in European nations where the virus is again surging.
The World Health Organization said a newly identified coronavirus variant in southern Africa was “of concern” on Friday, as countries around the world moved to restrict travelers arriving from that region to keep it from crossing their borders.
So far, only a few dozen cases of the new variant have been identified in South Africa, Botswana, Belgium, Hong Kong and Israel. There is no proof yet that the variant is more contagious or lethal, or could diminish the protective power of vaccines, but uncertainty on those questions was one factor in the speed of countries’ move toward restrictions.
On Friday evening, the World Health Organization gave the new version of the virus the name Omicron and called it a “variant of concern,” its most serious category. “This variant has a large number of mutations, some of which are concerning,” the W.H.O. said in its official description. “Preliminary evidence suggests an increased risk of reinfection with this variant.”
Earlier on Friday, the European Commission proposed that its member countries activate the “emergency brake” on travel from countries in southern Africa and other affected countries to limit the spread of the variant.
“All air travel to these countries should be suspended until we have a clear understanding about the danger posed by this new variant,” Ursula von der Leyen, the president of the European Union’s executive arm, said in a statement. “And travelers returning from this region should respect strict quarantine rules.”
In the past, governments have taken days, weeks or months to issue travel restrictions in response to new variants. This time, however, restrictions came within hours of South Africa’s announcement. At least 10 countries around the world had announced measures before South African scientists finished a meeting with World Health Organization experts about the variant on Friday.
The United States and Canada announced restrictions on travelers arriving from countries in southern Africa. Other governments that halted or restricted flights from South Africa included Bahrain, Belgium, Britain, Croatia, France, Germany, Israel, Italy, Japan, Malta, the Netherlands, Hong Kong, the Philippines and Singapore.
The new variant, initially called B.1.1.529, has a “very unusual constellation of mutations,” according to Tulio de Oliveira, director of the KwaZulu-Natal Research and Innovation Sequencing Platform. On the protein that helps to create an entry point for the coronavirus to infect human cells, the variant has 10 mutations, many more than the highly contagious Delta variant, Professor de Oliveira said.
Still, even epidemiologists who have been the most outspoken in supporting precautions against the virus urged calm on Friday, noting that little is known about the variant and that several seemingly threatening variants have come and gone in recent months.
“Substantively NOTHING is known about the new variant,” Roberto Burioni, a leading Italian virologist, wrote on Twitter, adding that people should not panic.
Stocks tumbled around the world on Friday as the news of the variant spooked markets and terrified many Europeans already exhausted by news of breakthrough infections, surging cases and rallies by vaccine skeptics.
Countries in Europe, once again the epicenter of the pandemic, were among the first to announce travel bans. Britain announced its restrictions on Thursday and put them into force on Friday.
“More data is needed but we’re taking precautions now,” Sajid Javid, the British health secretary, said on Twitter.
In the past two days, scientists in South Africa — which has a sophisticated detection system — discovered the variant after observing an increase in infections in South Africa’s economic hub surrounding Johannesburg.
“This variant did surprise us — it has a big jump in evolution, many more mutations than we expected, especially after a very severe third wave of Delta,” Professor de Oliveira said.
Australia has closed its borders to nine southern African countries in response to the emerging Omicron coronavirus variant, the government announced on Saturday.
Effective immediately, noncitizens from South Africa, Namibia, Zimbabwe, Botswana, Lesotho, Eswatini (the former Swaziland), the Seychelles, Malawi and Mozambique, will not be able to enter the country, health officials said.
All flights from the nine countries will be immediately suspended for 14 days. Australian citizens who arrive from those countries will need to quarantine in a hotel for two weeks, and anyone who has already arrived from those countries in the last two weeks must immediately isolate.
“These actions are taken on the basis of cautious prevention,” Health Minister Greg Hunt said at a news conference on Saturday. “We’re in a strong position but we know that acting early is what has protected Australia throughout the pandemic.”
He added that the government would “not hesitate” to expand the travel ban to other countries depending on how the situation develops in coming days and weeks.
No cases of the Omicron variant have been recorded yet in Australia, he said, although 20 people who recently arrived from South Africa are isolating in a quarantine camp. One person out of the 20 has tested positive and the case is being studied, he said.
The pharmaceutical company Merck said on Friday that in a final analysis of a clinical trial, its antiviral pill reduced the risk of hospitalization and death among high-risk Covid patients by 30 percent, down from an earlier estimate of 50 percent.
The lower efficacy is a disappointment for the drug, known as molnupiravir, which health officials around the world are counting on as a critical tool to save lives and reduce the burden on hospitals. It increases the importance of a similar, apparently more effective, offering from Pfizer that is also under review by the Food and Drug Administration.
A panel of advisers to the F.D.A. is set to meet on Tuesday to discuss Merck’s treatment and vote on whether to recommend authorizing it to treat high-risk Covid patients.
In briefing documents posted to the F.D.A.’s website on Friday, agency reviewers did not take a position on whether the drug should be authorized, though they found that the clinical trial data did not show any major safety concerns and that the drug was effective in preventing severe disease.
The reviewers said they had only become aware of the updated efficacy estimate earlier this week and were still reviewing the data. They said they could update their assessment when the panel meets on Tuesday.
Merck’s initial estimate that the drug reduced hospitalization and death by 50 percent came from an early look at results from 775 study participants. The updated figure announced on Friday came from more than 1,400. In the final analysis, the participants who received molnupiravir had a 6.8 percent risk of being hospitalized, and one patient died. Those who received a placebo had a 9.7 percent risk of being hospitalized, and nine died.
Dr. David Boulware, an infectious disease researcher at the University of Minnesota, said he expected the drug would still receive emergency authorization. If the expert committee endorses it and the F.D.A. heeds the recommendation, the treatment could be authorized in the United States as soon as next week.
“The reduction in hospitalization is a little bit less, but there is still a big mortality benefit if you start early,” he said.
Still, he said, molnupiravir will probably be deemed a lower-tier treatment, an alternative choice for people who can’t get or don’t want more effective treatments.
Monoclonal antibody drugs, which are typically administered intravenously in the United States, have been found to reduce hospitalizations and deaths by at least 70 percent. Pfizer’s antiviral pill, Paxlovid, which was found in a clinical trial to cut the risk of hospitalization and death by 89 percent, could become available within weeks. Fluvoxamine, a common and inexpensive antidepressant, appears to be about as effective as molnupiravir.
Meant to be dispensed at pharmacies and taken at home, Merck’s drug is the first in a new class of antiviral treatments for Covid that are expected to reach many more people than other treatments have. Public health experts say that while the pills are no substitute for vaccination, they have the potential to prevent severe illness and save lives.
Scientists are still unclear on how effective vaccines will be against the new variant flagged by a team in South Africa, which displays mutations that might resist neutralization. Only several dozen cases have been fully identified so far in South Africa, Botswana, Hong Kong, Belgium and Israel.
The new variant, designated by the World Health Organization as a “variant of concern” known as Omicron, has a “very unusual constellation of mutations,” with more than 30 in the spike protein alone, according to Tulio de Oliveira, director of the KwaZulu-Natal Research and Innovation Sequencing Platform.
The spike protein is the chief target of human antibodies that the immune system produces to fight a coronavirus infection. So many mutations raised concerns that Omicron’s spike might be able to evade antibodies produced by either a previous infection or a vaccine.
The variant shares similarities with the Lambda and Beta variants, which are associated with an innate evasion of immunity, said Richard Lessells, an infectious diseases specialist at the KwaZulu-Natal Research and Innovation Sequencing Platform.
“All these things are what give us some concern that this variant might have not just enhanced transmissibility, so spread more efficiently, but might also be able to get around parts of the immune system and the protection we have in our immune system,” Dr. Lessells said.
The new variant has largely been detected among young people, the cohort that also has the lowest vaccination rate in South Africa. Just over a quarter of people ages 18 to 34 in South Africa are vaccinated, said Dr. Joe Phaahla, the country’s health minister.
While cases of the variant are mainly concentrated in the country’s economic hub — particularly in its administrative capital, Pretoria — it is “only a matter of time” before the virus spreads across the country as schools close and families prepare to travel for the holiday season, Dr. Phaahla said.
An earlier version of this article incorrectly referred to a receptor found on some human cells known as ACE2, an abbreviation for angiotensin-converting enzyme 2. The ACE2 is part of a human cell, not part of the spike protein on the surface of the coronavirus.
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.
PARIS — Protesters fired live ammunition at journalists and the police on Thursday night on the French Caribbean island of Martinique, injuring dozens of officers, one of them seriously, a spokesman for the French government said.
As in Guadeloupe, another French island to the north, the protests against Martinique’s coronavirus protocols — which require vaccinations for health care workers and a health pass to enter most public venues — have been exacerbated by long-running frustrations and anger over economic inequality with the mainland. The poverty rate in Martinique is 29.8 percent, almost twice the national level in France.
The mix of old grievances and new anger over Covid-19 rules has made the unrest particularly volatile.
“These extremely serious acts call for unanimous and unambiguous condemnation,” the French prime minister, Jean Castex, said in a tweet on Friday in response to the violent protests in Martinique’s largest city, Fort-de-France.
An arson attempt at the official residence of France’s most senior representative on the island was also reported. The local police office declined to comment on the report.
On Thursday evening, the local authorities had announced a curfew from 7 p.m. to 5 a.m. “until a return to calm.” The curfew was in response to nighttime violence since Monday.
Nearly 150 people have been arrested in Guadeloupe and Martinique since the beginning of the crisis, according to the government spokesman, Gabriel Attal. Ten of the arrests were made on Thursday night, according to Interior Minister Gérald Darmanin, who said in a tweet, “Everything is being done to find those responsible.”
The central government also announced that it would extend until Dec. 31 the deadline for health care workers in Martinique and Guadeloupe to complete their coronavirus vaccinations.
The new variant that emerged in southern Africa could pose “a substantial risk to public health,” Britain’s health secretary, Sajid Javid, said on Friday, explaining a British decision to suspend flights and place six African countries on a quarantine list.
“This new variant is of huge international concern,” Mr. Javid said in a statement to Parliament while adding that no cases have yet been detected in the U.K.
Mr. Javid described the situation as fast moving and said there was a high degree of uncertainty around the spread of the virus and its possible impact. But he suggested that the signs were worrying.
“Early indications show that this variant may be more transmissible than the Delta variant and current vaccines may be less effective against it,’’ he said.
Late on Thursday Britain said it was suspending flights temporarily from South Africa, Botswana, Lesotho, Eswatini, Namibia and Zimbabwe. When they start up again, British and Irish citizens returning from these countries will be required to quarantine in government-approved hotel facilities.
Mr. Javid said that assessments were being made of the situation in other nations with strong travel links to South Africa, suggesting that the list of so-called “red list” countries could grow.
“The sequence of this variant, currently called B.1.1.529, was first uploaded by Hong Kong from a case of someone traveling from South Africa,” Mr. Javid said. “Further cases have been identified in South Africa, in Botswana, and it is highly likely that it has now spread to other countries.”
Early in the pandemic the British government was criticized for delaying the introduction of its quarantine system and the swiftness of Thursday’s move reflects a desire not to repeat that mistake.
“One of the lessons of this pandemic is that we must move quickly and at the earliest possible moment,” said Mr. Javid.
Speaking for the opposition Labour Party, Alex Norris welcomed the move but said that the emergence of the new variant reflected the “failure of the global community to distribute the vaccine” around the world.
Nearly 20 months after pandemic lockdowns first began, governments across Europe are beginning to tighten restrictions again amid the latest wave of new coronavirus cases, threatening the gains that the region has made against the pandemic.
France is racing to offer booster shots to all adults and will not renew health passes for those who refuse. Deaths are rising in Germany, with its 68 percent vaccination rate, a worrying trend for a highly inoculated country. Austria has been in a nationwide lockdown since Monday, and made vaccinations mandatory.
In Eastern Europe, where far-right and populist groups have fueled vaccine skepticism, vaccination rates are lower than the rest of the continent. Bulgaria, where a quarter of the population is fully vaccinated, is turning back to shutdowns or other restrictive measures.
The quickly deteriorating situation in Europe is worrisome for the United States, where the seven-day average of new cases has risen 24 percent in the past two weeks. (The number of new deaths reported in the United States is down 6 percent.) Trends in new cases in the United States have tended to follow Europe by a few weeks.
“Time and again, we’ve seen how the infection dynamics in Europe are mirrored here several weeks later,” Carissa F. Etienne, director of the Pan American Health Organization, told reporters on Wednesday. “The future is unfolding before us, and it must be a wake-up call for our region because we are even more vulnerable.”
The White House insists that while new infections are on the rise, the United States can avoid European-style lockdowns.
“We are not headed in that direction,” Jeff Zients, the White House coronavirus response coordinator, said this week. “We have the tools to accelerate the path out of this pandemic: widely available vaccinations, booster shots, kids’ shots, therapeutics.”
But the chief of the World Health Organization, Tedros Adhanom Ghebreyesus, said that some countries had lapsed into a “false sense of security.”
He issued a warning during a news briefing on Wednesday: “While Europe is again the epicenter of the pandemic, no country or region is out of the woods.”