Life in Australia has all but bounced back following the devastating spread of the highly transmissible Delta variant, which entered Australia via an infected flight attendant in mid-June, plunging much of the country in months-long lockdowns. But as Australia prepares to reopen its international borders to the world from December 1, fresh concerns about a newly discovered and highly mutated Covid variant, named by the WHO Omicron, have cast doubt on whether the nation’s reopening will go ahead as planned.
Any apparent complacency around the Delta strain, which caught Australia off guard after months of zero community transmission, has been replaced with extreme caution from federal authorities. But how dangerous is this new variant and how likely is it to enter the country?
What is Omicron and why is it a ‘variant of concern’?
Originally known as variant B.1.1.529, Omicron was first detected and sequenced in the Gauteng province of South Africa, where the nation’s two largest cities, Pretoria and Johannesburg, are located. While it was detected there, it is not certain that the strain originated in South Africa. New variants of the virus are characterised by mutations when compared to previously known strains, however, Omicron is particularly concerning because of the number of mutations. There are more than 30 distinct mutations to Omicron’s spike protein – the distinctive points that cover the virus and allow it to enter a cell and begin replicating – which is at least double the number of mutations found in the Delta strain. Typically, mutations found in a virus emerge incrementally, but such a radical change to the virus has alarmed many scientists. Although there are still too few cases worldwide to fully understand what risks the new variant poses, the sheer number of mutations has led scientists to speculate that Omicron could be even more transmissible than Delta and might be able to bypass naturally acquired immunity from a previous infection. Cases in South Africa jumped from 273 on November 16 to more than 1,200, in less than a week.
It is still too early to tell if the new variant can evade vaccine protection, but while its transmissibility may be higher, it does not appear as yet that Omicron causes more severe illness or a higher mortality rate, although it may be weeks before enough data has been collected to fully confirm this.
What are Australian authorities doing about the threat of Omicron?
On November 27, the federal government suspended inbound flights from nine southern African countries – South Africa, Namibia, Zimbabwe, Botswana, Lesotho, Eswatini, the Seychelles, Malawi and Mozambique – and closed its borders to any foreign national who has visited any of those countries within the past 14 days. This mirrors similar travel embargos introduced by the US, UK and multiple European countries. Australian nationals who are returning home from any of the above African regions will still be allowed to enter the country but will be required to complete 14-days of hotel quarantine. Anyone who has already entered Australia from any of the banned countries is required to immediately get tested and isolate for 14 days. The federal government has said that these measures will pertain to fewer than 100 people nationwide, and that 20 people from South Africa who have entered the country within the past week are already in quarantine at the Howard Springs facility in the NT. One person from that group has tested positive, although it is not yet known if the infection is Omicron.
Federal health minister Greg Hunt said that “strong, swift, decisive and immediate actions” were necessary to prevent a scenario unfolding similar to the Delta outbreak, but that all current actions were precautionary, as much is still unknown about the threat of Omicron. Restrictions could be scaled up or wound back quickly, Hunt said, adding that there could be confidence that Australia’s high levels of vaccination protection – more 92 per cent of Australians over the age of 12 has received at least once dose of a vaccine, and in both NSW and Canberra, more than 90 per cent of the adult population is already fully vaccinated – would prevent future lockdowns.
How likely is it that Omicron will enter Australia?
While the majority of cases remain situated in southern Africa, there have already been cases identified in Isreal, Hong Kong and Belgium. And given that community transmission is significant in Africa and vaccination rates low – less than 6 per cent of the population of the African continent has been vaccinated – there are likely to be cases spreading undetected that could create chains of transmission that spread internationally. As yet, the government's plans to open international borders to visa holders and tourists from Japan and Korea from December 1 are going ahead as planned, but it seems likely that certain additional protections, such as hotel quarantine, may be reintroduced to mitigate the risk of Omicron reaching the Australian population.