Australia "cannot keep the Omicron variant out forever" but a pause on its reopening plans will provide precious breathing space, the chief medical officer says.
Health Minister Greg Hunt has also revealed authorities believed the highly-infectious new strain, emanating out of southern Africa since last week, was "manageable".
The federal government announced on Monday evening the return of roughly 200,000 skilled migrants, international students, and humanitarian visa holders would be pushed back until December 15.
It remains unclear whether the Omicron variant is more severe than previous variants, or undermined the effectiveness of vaccines.
Chief medical officer Paul Kelly said the two-week delay provided time to assess emerging data, but the government remained committed to its suppression strategy.
"This is a temporary pause so we can get that information that we need," he said.
"We cannot keep this Omicron variant out forever from Australia; eventually it will be here. Most importantly now, we do what we can to slow down that introduction."
The comments came before NSW Brad Hazzard told 7 News a woman in her 30s had visited several venues on the NSW Central Coast while positive to the strain.
That case would take the total number of confirmed Omicron cases across Australia to six. There were four in hotel quarantine in NSW and one at the Howard Springs quarantine facility in the NT.
Professor Kelly said they were fully-vaccinated, some had had a previous COVID-19 infection, and had very mild or no symptoms.
Mr Hunt said an April pause on flights from India had slowed the spread of the Delta strain, but not every future variant would be met with similar disruption.
"We're doing this out of an abundance of caution. But our overwhelming view is that whilst it's an emerging variant, it's a manageable variant ... I would say that other variants have not led to change. Again, we follow the medical advice," he said.
The Australian Technical Advisory Group was mulling an application from Pfizer to vaccinate children aged 5 to 11. Mr Hunt said there had been "good progress", and expected a rollout to begin in early January.
"At this stage, there are no red flags and we're expecting that to occur in the coming weeks," he said.
ATAGI was also reviewing whether booster shots for Australians should be sped up because of the new variant. About 430,000 booster shots have been administered across the country.
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The UK has expanded its booster program to all adults, and cut waits between second and third doses from six months to three months, as the northern hemisphere braced for a spike in cases over winter.
Professor Kelly said expediting boosters during winter "made a lot of sense", but the government would wait for ATAGI's advice before acting.
"We're more than six months away from winter. We know that respiratory viruses circulate more in winter. It's likely that that would be when we really want the boosters to be actively working," he said.
The arrival of Omicron came with vaccination rates among Indigenous Australians continuing to lag behind the broader population.
More than 92 per cent of Australians aged 16 or over had received at least one dose, while 87 per cent were fully vaccinated. But among Indigenous Australians, those figures dropped to just 74 per cent and 62.6 per cent.
Anti-vaccine conspiracy groups have also launched social media campaigns in remote areas, which Mr Hunt conceded had contributed to "significant hesitancy" among Indigenous Australians.
But the Health Minister claimed the tide was turning, singling out the NT and Western Australia for particular praise.
"We're seeing that that initial hesitancy is beginning to fall away," he said.