Medical authorities are warning of a new surge of COVID-19 cases in Australia.
Chief Medical Officer Paul Kelly told ABC News Breakfast on Monday that with borders now open it was only "a matter of time" until cases started rising again across the country.
He said the increase in cases had been particularly strong in Victoria and Western Australia, but urged all Australians to "take sensible precautions over the coming weeks" as cases were likely to continue rising.
Here's what we know about the increase in case numbers.
New variants are likely causing more infections and reinfections
Professor Kelly said new variants of COVID-19 are likely a key reason for rising case numbers.
Omicron sub-variants XBB, BQ 1.1 and B2 have been identified in parts of the country recently.
"All of our early indicators over the last week or so have demonstrated that case numbers are rising," Professor Kelly said.
"It is probably related to these couple of new variants that we are now seeing in Australia that have been seen around the world.
"They are still in a minority, but they are more transmissible. So it's likely that people will become infected, maybe reinfected."
Professor Kelly said Australians' "high hybrid immunity" — immunity gained from both vaccinations and previous infections — will keep many protected from severe disease.
Here's how Australia's COVID-19 case numbers have fared over the past month (you can hover over a state or territory to see its numbers):
Hospitalisations are stable, but people should be cautious
Professor Kelly said there was no extra pressure on Australia's hospital system at the moment, but he urged people to remain vigilant.
"There hasn't really been a rise in hospital cases to a great extent," he said.
"Very few cases in intensive care — only just over 40 cases on average at the moment in the last week."
Professor Kelly said the increase in cases was predominantly seen outside of hospitals, and urged people to get vaccinated, or wear a mask or get tested if they felt unwell.
"Those clear messages that we have had for some time about wearing a mask if you feel unwell or to protect yourself in crowded situations," he said.
"To get a test, particularly if you are in those vulnerable groups that could actually have antiviral treatment right now, particularly people over the age of 70. That is very effective if given quickly.
"Now is the time to actually consider whether you are eligible and due for another dose of vaccine, whether that be a third or fourth dose.
"There are still a large number of people that have not had a third dose. This is a chance to get that."
Here's how hospitalisation numbers looked across Australia over the past month:
Tests are still effective against new variants, CMO says
Professor Kelly said the most common tests for COVID-19 were still effective against the new variants, as far as experts knew.
"These are new variants in the last few weeks and the TGA (Therapeutic Goods Administration) is continuing to do that testing of rapid antigen tests against different strains of the virus, so we will keep watching that," he said.
"Of course, PCRs (Polymerase Chain Reaction tests) are still available."
Professor Kelly said now was also a good opportunity for people who were eligible to receive COVID-19 antivirals to get a test and see their GP.
"Having a plan to do that, if you are to become sick, is an important thing," he said.
Deaths from COVID-19 have also remained stable, but may appear skewed by some historical data supplied by health authorities.
