Flights from nine countries in southern Africa are suspended and arrivals who have been in the region will be forced into mandatory quarantine, as Australia scrambles to respond to a "concerning" new variant of COVID-19
There are no known cases of the Omicron strain in Australia yet, but Health Minister Greg Hunt on Saturday said precautionary measures were needed.
Flights from South Africa, Namibia, Zimbabwe, Botswana, Lesotho, Eswatini, the Seychelles, Malawi and Mozambique will cease for two weeks.
Non-citizens who have been in those countries aren't allowed into Australia.
Australian citizens and their dependents face mandatory two-week quarantine if they have been in the region.
The new variant, named Omicron by the World Health Organisation on Saturday, has been detected in South Africa, Botswana, Hong Kong, Israel, Belgium and the United Kingdom.
It has double the number of mutations as the Delta variant that sparked a third wave of outbreaks and lockdowns in Australia this year.
Several states have tightened measures in response to the possible risk.
In NSW, arrivals who have been overseas recently - not just in southern Africa - will need to isolate at home for 72 hours.
People already in the state who have been in the nine countries in the past two weeks must isolate for 14 days and be immediately tested.
Anyone in the ACT who has been to the nine countries in the past 14 days must get a PCR test and quarantine immediately.
ACT Health will also implement quarantine requirements for fully vaccinated overseas travellers who have not been in these countries.
These travellers must quarantine until 11.59pm Tuesday November 30.
South Australia extended the length of its quarantine requirement for fully-vaccinated Australian international arrivals to two weeks, and made small changes to its interstate arrival regime.
West Australian Premier Mark McGowan announced SA would be designated 'low risk', introducing a quarantine requirement for international arrivals from the state. He said it was necessary because of quarantine requirements loosening in recent days.
Tasmania will bar entry to people who have been in southern Africa unless they' have first completed two weeks of supervised quarantine on the mainland.
Commonwealth Chief Medical Officer Paul Kelly said Omicron was spreading quickly, but it wasn't clear that it caused more severe symptoms than existing strains.
It is not yet known whether existing vaccines are any less effective against the new variant than prevailing strains.
There were nearly 1500 new cases reported nationally on Saturday, including 1252 in Victoria, 235 in NSW, seven in the ACT and one each in Queensland and the Northern Territory.
Five more deaths were recorded in Victoria.
On the latest figures, 92.2 per cent of people 16 and over in Australia have received at least their first vaccine dose and 86.55 per cent both.
© AAP 2021