World confronts new threat

A new, possibly more infectious coronavirus variant, with an unusual number of mutations, has scientists sounding the alarm and countries moving to impose travel restrictions, as the world fears another setback on the long road out of the Covid-19 pandemic.

The latest variant arrives nearly two years after the first ominous warnings about a novel coronavirus emerged from China. Now, as the world grows increasingly weary of measures to contain the virus, the new threat is casting a shadow across holiday celebrations.

The World Health Organisation yesterday declared the mutation-laden virus a ‘‘variant of concern’’ after a fullday review by the group’s scientists, and dubbed it the Omicron variant, after a Greek letter.

‘‘This variant has a large number of mutations, some of which are concerning,’’ the

WHO said. ‘‘Preliminary evidence suggests an increased risk of reinfection with this variant, as compared to other’’ variants of concern.

In many ways, the virus is acting exactly as global health experts have warned it might – creating new and potentially more dangerous variants, first detected in under-vaccinated parts of the world. Still, major questions remain about Omicron’s origins, transmissibility, whether it might make people sicker, and whether it might be able to evade vaccines or therapeutics.

Scientists in South Africa said they had linked Omicron to

an exponential rise of infections in the country. Cases have also been identified in Belgium, Botswana, Hong Kong, Israel and other countries.

Britain, Canada, France, Israel and Japan have banned or ordered quarantines for air passengers arriving from the southern African region. European Union countries have agreed to ban air travel from seven southern African countries.

South African health officials decried the world’s reaction as unjustified, saying South Africa should not be ‘‘punished’’ for

making the discovery, particularly because the Omicron variant’s origin remained unknown.

Chief among experts’ concerns is whether coronavirus vaccines will prove less powerful against Omicron, and whether they could be adapted to target the new variant.

Pfizer and BioNTech said they expected to have data within two weeks on whether Omicron may require an adjustment to their coronavirus vaccine.

The companies said they had been working to adapt their

mRNA vaccine ‘‘within six weeks, and ship initial batches within 100 days in the event of an escape variant’’. They had begun clinical trials to test their vaccine against other variants.

Moderna, maker of another mRNA coronavirus vaccine, said it was ‘‘working rapidly’’ to test the ability of its vaccine to neutralise the Omicron variant, and it expected to have data ‘‘in the coming weeks’’.

Africa began ramping up its monitoring of Covid-19 variants several months ago, made wary by the Delta variant’s destructive sweep across India and the continent’s low vaccination rates, which some officials have blamed on ‘‘vaccine hoarding’’ by wealthier countries.

Even before the latest variant emerged, Europe was applying new lockdowns and travel restrictions for unvaccinated residents in an attempt to contain a surge in coronavirus cases.

Reported deaths in Europe reached nearly 4200 a day last week – twice the number since the end of September, according to the WHO. Covid-19 cases fuelled by the Delta variant have been surging in some US states, including Michigan and Minnesota.

Australia has shut its borders to nine southern African countries and suspended all flights from that region amid growing concerns about the new Omicron variant.

All flights have been immediately suspended for two weeks from South Africa, Namibia, Zimbabwe, Botswana, Lesotho, Eswatini, the Seychelles, Malawi and Mozambique. Any Australian citizens or dependents who have been been in those countries in the past 14 days must go into mandatory quarantine, and noncitizens who have been in southern Africa will be banned from entering Australia.

Chief Medical Officer Paul Kelly said it was premature to be talking about whether domestic lockdowns or further restrictions would be needed to stop the spread of Omicron in Australia.

About 86 per cent of Australians aged 16 and older are double-dosed.