The number of countries where the new coronaviruses variant has been found has been increased to at least 20, raising questions about whether the epidemic is about to surge again.
The Netherlands' National Institute for Public Health and the Environment said that samples taken on Nov. 19 and Nov. 23 tested positive for the variant. Health officials are trying to limit the spread of the disease by notifying the two people.
Scientists say that the Omicron variant is more contagious than previous forms of the virus. The evidence so far is sobering, but they caution that they cannot be sure without more testing and data.
On Tuesday, the Biden administration was looking at ways to toughen coronaviruses screening for people flying to the United States, including whether to require all passengers to provide a negative result from a test taken within 24 hours of departure.
The current rules that allow fully vaccineed people to take a test up to three days before they leave for the US might not be stringent enough.
Travelers from South Africa are being tested for Covid-19 at the airport.
Unvaccinated people who are over the age of 60 should be advised to delay travel, according to the World Health Organization. The prime minister of Greece announced that people over the age of 60 would be required to have a Covid vaccine.
In South Africa, where the variant was first announced and is already widespread, reported new coronaviruses cases have rocketed from about 300 a day in mid-November to about 3000 a day, the fastest rate of increase in the world. At least 14 of the 61 passengers tested positive for the virus on two flights from South Africa to the Netherlands on Friday, just as a cascade of bans on travel from southern Africa were being announced.
Scientists don't have other answers to the question of vaccine effectiveness against Omicron. Is it treatments? Does Omicron cause more serious illnesses?
The data is still sparse and experts cautioned not to put too much stock in reports that the variant is causing only mild illness. Early evidence from South Africa shows that Omicron is infecting people who have already had Covid-19, but that requires rigorous testing.
The top U.S. infectious disease expert said Tuesday at a White House briefing that it will be two to four weeks before preliminary answers are available.
There have been no Omicron cases reported in the United States as of Tuesday evening. The goal should be to slow its spread, as officials say it is just a matter of time.
The variant has turned up in Brazil, which would mean it is already on all of the planet.
The CDC is analyzing the genomes of 80,000 coronavirus samples weekly and will step up checks on arriving international passengers.
The Temple Underground station is in London. British officials say they expect Omicron infections to increase.
The variant has a large number of changes not seen before, including more than 30 on the spike, which is the primary target of the vaccines. There is uncertainty over whether the fears about Omicron are overblown.
Several times before, nations relaxed their guard, thinking that the worst of the Pandemic was over, only to be swamped by another wave caused by the Delta variant.
Vaccine makers are looking into reformulating their shots to address Omicron, a step that was not required for fighting Delta.
Regeneron said Tuesday that its therapy might not work as well against Omicron. The FDA advisory panel recommended approval of an oral treatment to reduce the severity of Covid, made by Merck, and will soon consider another from Pfizer.
In previous waves of the Pandemic, there were more cases when the first cases were detected than when the first variant was found.
The majority of Africans have not had a vaccine, but many people in the wealthiest countries have. New variant will emerge if there are not many people who arevaccinated.
The head of the World Health Organization said Monday at the start of a conference thatVaccine equity is not charity and is in every country's best interests.
He said that the time has come for countries to agree on a binding approach to a common threat.
Travelers returning to South Africa at the O.R. Tambo International Airport on Saturday.
African countries still face challenges in distribution and overcoming vaccine hesitancy, despite the fact that vaccine doses are becoming more plentiful. South Africa turned away a shipment because they were unsure if they could use it in time.
The new variant was found in two different places, first in Botswana and then in South Africa. Researchers in South Africa have found it in samples from as far back as Nov. 9, and experts think it's likely that it was circulating even earlier.
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The number of confirmed cases is small in Europe, but officials are bracing for more.
Is there a chance of community transmission? Sajid Javid is the British health secretary. I think we have to be realistic, as we are seeing in other European countries. We would expect cases to increase as we look for more cases.
The timing is bad for a continent already gripped by the biggest wave yet, forcing governments to scale back plans to remain open for the holidays.
European countries report more than two million new coronaviruses each week, more than half of the world total, although with vaccinations and improved treatments, deaths have declined compared with a year ago. Germany, the Netherlands, Belgium, Hungary, the Czech Republic, Slovakia, Denmark and Norway all set records for new cases last week.
People who have recently been in South Africa and several neighboring countries have been barred entry by governments in the United States, Europe and elsewhere.
The two flights that arrived in Amsterdam on Friday night from South Africa show how late such measures might be.
Many flights were canceled at the O.R. Tambo International Airport in South Africa on Tuesday.
With the travel ban in effect, more than one in 10 passengers had the virus, so how many other travelers have gone undetected is anyone's guess.
The Dutch public health institute said that 14 of the passengers from South Africa had the Omicron variant, which was not yet known to the world.
It said that the people were likely to have different sources and locations for their infections.
The reporting was done by Mark Landler, Rebecca Robbins, Megan Specia, and Michael D. Shear.
