BERLIN —

       The Netherlands confirmed 13 cases of the new Omicron variant of the coronavirus and Australia found two on Sunday as the countries half a world apart became the latest to detect it in travelers arriving from southern Africa.

       A growing raft of curbs are being imposed by nations around the world as they scramble to slow the variant’s spread, with Israel deciding Sunday to bar entry to foreign nationals in the toughest move so far.

       Confirmed or suspected cases of the new variant have already emerged in several European countries, in Israel and in Hong Kong, just days after it was identified by researchers in South Africa. The “act first, ask questions later” approach reflected growing alarm about the emergence of a potentially more contagious variant nearly two years into a pandemic that has killed more than 5 million people, upended lives and disrupted economies across the globe.

       While much remains to be learned about the new variant, researchers are concerned that it may be more resistant to the protection provided by vaccines and could mean that the pandemic lasts for longer than anticipated.

       Advertisement

       The Dutch public health authority confirmed that 13 people who arrived in the Netherlands on flights from South Africa on Friday have so far tested positive for Omicron. They were among 61 people who tested positive for the virus on Friday after arriving on the last two flights to Amsterdam’s Schiphol airport before a flight ban was put in place. They were immediately put into isolation, most at a nearby hotel, while sequencing was carried out.

       California

       Omicron variant adds new peril to holiday season in California and beyond

       The Omicron variant, first identified in South Africa, has more mutations than any scientists have seen, including some that may make it less susceptible to immunity generated from previous infections or vaccines.

       Authorities in Australia said two overseas travelers who arrived in Sydney from Africa became the first in the country to test positive for the Omicron variant. Arrivals from nine African countries are now required to quarantine in a hotel upon arrival.

       Israel moved to ban entry by foreigners and mandate quarantine for all Israelis arriving from abroad.

       “Restrictions on the country’s borders is not an easy step, but it’s a temporary and necessary step,” Prime Minister Naftali Bennett said at the start of the weekly Cabinet meeting.

       Dr. Ran Balicer, head of the government’s advisory panel on COVID-19, told Israel’s Kan public radio that the new measures were necessary for the “fog of war” surrounding the new variant, saying it was “better to act early and strictly” to prevent its spread.

       Dutch Health Minister Hugo de Jonge said he has asked his country’s public health institute for advice on whether additional travel restrictions are needed, but he said he wants to coordinate with his European Union counterparts because “I think those are really steps that we will have to take together.”

       Many countries have restricted or banned travel from various southern African countries — among the latest New Zealand, Thailand, Indonesia, Singapore, Sri Lanka, the Maldives and Saudi Arabia. Places that already had imposed restrictions include Brazil, Canada, the European Union, Iran and the U.S. This goes against the advice of the World Health Organization, which has warned against any overreaction before the variant is thoroughly studied.

       South Africa’s government responded angrily to the travel bans, which it said are “akin to punishing South Africa for its advanced genomic sequencing and the ability to detect new variants quicker.” It said it will try to persuade countries that imposed them to reconsider.

       “Whilst we respect the right of all countries to take the necessary precautionary measures to protect their citizens, we need to remember that this pandemic requires collaboration and sharing of expertise,” the minister for international relations and cooperation, Naledi Pandor, said in a statement.

       Authorities in Australia said two overseas travelers who arrived in Sydney from Africa became the first in the country to test positive for the Omicron variant. Arrivals from nine African countries are now required to quarantine in a hotel upon arrival.

       The United States’ top infectious diseases expert, Dr. Anthony Fauci, said he would not be surprised if the Omicron variant was already in the U.S., too.

       World & Nation

       Omicron coronavirus variant seen as a clarion call to vaccinate the globe

       While jabs and boosters are offered in the U.S. and much of Europe, vaccination rates remain low in southern Africa, where the Omicron variant was first detected.

       “We have not detected it yet, but when you have a virus that is showing this degree of transmissibility ... it almost invariably is ultimately going to go essentially all over,” Fauci said on NBC television.

       In Europe, much of which already has been struggling with a sharp increase in cases over recent weeks, officials also were on their guard.

       The U.K. on Saturday tightened up rules on mask-wearing and on testing of international arrivals after finding two Omicron cases. Spain announced it won’t admit unvaccinated British visitors starting Dec. 1. They are currently allowed to enter with a negative coronavirus test.

       Italy was going through lists of airline passengers who arrived in the past two weeks after a business traveler who returned from Mozambique and landed in Rome on Nov. 11 tested positive for Omicron.

       “The phase of searching for the new variant has started. Controls at airports, ports and train stations have been reinforced,’’ said the Lazio region’s top health official, Alessio D’Amato. The region that includes Rome’s Leonardo da Vinci international airport also is sending random virus test samples to the Spallanzani infectious disease hospital in Rome to be analyzed for the new variant.

       French Health Minister Olivier Veran said that while no cases have yet been confirmed in France, “it’s a question of hours,” given that Omicron infections have been reported in multiple neighboring countries. “It is probable that there currently are cases in circulation,” he said on a visit to a Paris vaccination center.

       While it is not clear yet how existing vaccines work against the Omicron variant, Veran said the French government isn’t changing its strategy to fight the latest surge of infections driven by the Delta variant, which centers on increasing vaccinations and boosters.

       David Hui, a respiratory medicine expert and government advisor on the pandemic in Hong Kong, said that even though it is not clear if current COVID-19 vaccines are effective against the new variant, the city’s vaccination rate should be increased and booster doses should be implemented as soon as possible.

       He said that the two people who tested positive for the Omicron variant had received the BioNTech-Pfizer shot and exhibited very mild symptoms, such as a sore throat.

       “Vaccines should work but there would be some reduction in effectiveness,” he said.