Global authorities reacted with alarm on Friday to a new coronavirus variant detected in South Africa, with the EU and Britain among those tightening border controls as researchers sought to find out if the mutation was vaccine-resistant.
Hours after Britain banned flights from South Africa and neighbouring countries and asked travellers returning from there to quarantine, the World Health Organization (WHO) cautioned against hasty measures.
One South African scientist expert labelled London’s decision a symptom of "vaccine apartheid", though European Commission chief Ursula von der Leyen said the EU also aimed to halt air travel from the region and several other countries including India, Japan and Israel toughened curbs.
In Washington, top US infectious disease official Anthony Fauci said no decision had been made on a possible US travel ban, reports Reuters.
There was no indication that the variant was in the United States, and it was unclear whether it was resistant to current vaccines, he told CNN.
The WHO said it would take weeks to determine how effective vaccines were against the variant, which was first identified this week, but the news pummelled global stocks and oil amid fears what new bans would do to the global travel industry and already shaky economies across southern Africa.
The variant has a spike protein that is dramatically different to the one in the original coronavirus that vaccines are based on, the UK Health Security Agency said, raising fears about how current vaccines will fare.
"As scientists have described, (this is) the most significant variant they've encountered to date," British Transport Secretary Grant Shapps told Sky News.
In Geneva the WHO - whose experts on Friday discussed the risks that the variant, called B.1.1.529, presents - warned against travel curbs for now.
"At this point, implementing travel measures is being cautioned against," WHO spokesperson Christian Lindmeier told a UN briefing. "The WHO recommends that countries continue to apply a risk-based and scientific approach when implementing (curbs)."
It would take several weeks to determine the variant's transmissibility and the effectiveness of vaccines against it, Lindmeier said, noting that 100 sequences of it had been reported so far.
British health minister Sajid Javid said the sequence of the variant was first uploaded by Hong Kong from someone travelling from South Africa.
"Further cases have been identified in South Africa and in Botswana, and it is highly likely that it has now spread to other countries," Javid told lawmakers.
What we know about the COVID-19 variant detected in South Africa
Israel imposed a travel ban covering most of Africa as Prime Minister Naftali Bennett said a few cases had been reported there.
Israel's Ynet news website said that, according to the Health Ministry, one of those individuals had received a third shot, or booster, of the Pfizer-BioNTech COVID-19 vaccine two months ago. A Health Ministry spokesperson could not confirm the report.
"We are currently on the verge of a state of emergency, " Bennett said in a statement from his office.
"Our main principle is to act fast, strong and now."
TOO LATE FOR TRAVEL CURBS?
One epidemiologist in Hong Kong said it may be too late to tighten travel curbs.
"Most likely this virus is already in other places. And so if we shut the door now, it’s going to be probably too late," said Ben Cowling of the University of Hong Kong.
South Africa will speak to British authorities to try to get them to reconsider their ban, the foreign ministry in Pretoria said.
Richard Lessells, a South Africa-based infectious disease expert involved in detecting variants, also expressed frustration at travel bans, saying the focus should be on getting more people vaccinated in places that have struggled to access sufficient shots.
"This is why we talked about the risk of vaccine apartheid. This virus can evolve in the absence of adequate levels of vaccination," he told Reuters.
In South Africa, about 35 per cent of adults are fully vaccinated, higher than in most other African nations but around half average levels in developed countries.
European states had already been expanding booster vaccinations and tightening curbs as the continent battles a fourth COVID-19 wave, led by the Delta variant that current vaccines are effective against, with many reporting record daily rises in cases.
Discovery of the new variant comes as Europe and the United States enter winter, with more people gathering indoors in the run-up to Christmas, providing a breeding ground for infection.
Italy imposed an entry ban on people who have visited southern African states in the last 14 days, while France suspended flights from southern Africa and Bahrain and Croatia will ban arrivals from some countries.
India issued an advisory to all states to test and screen international travellers from South Africa and other "at risk" countries, while Japan tightened border controls.
The coronavirus has swept the world in the two years since it was first identified in central China, infecting almost 260 million people and killing 5.4 million.