Western Australia is drawing closer to the expected peak of its Omicron outbreak with 4535 new COVID-19 cases and more hospitalisations.
Eighty people are in hospital with the virus, including three who are in intensive care but are not believed to be on ventilators.
The number of active cases has swelled to more than 18,000.
Authorities expect the outbreak to peak at around 10,000 daily infections as soon as next week, with hospitalisations to lag beyond that.
"If the modelling is correct, we hope to be over the worst of it by the end of this month," Health Minister Amber-Jade Sanderson told reporters on Thursday.
"We would hope that the peak lasts hopefully no more than a week. But again, Western Australia is a bit of a experiment population.
"We haven't had large amounts of COVID in the community, we have exceptionally high vaccination rates, so actually we don't know exactly what's going to happen."
Ms Sanderson said the number of people in hospital was likely to peak around the end of March.
"This is going to get difficult. We will see more people in hospital and more people in ICU," she said.
"The health system will be dealing with COVID for many, many weeks, and in fact many months to come. Because we are hoping to flatten that curve, the tail may be a little longer and higher."
Around 50 per cent of the people in hospital with COVID-19 in WA were unvaccinated, the health minister said.
"There's no stronger evidence (of the benefits of vaccination) than this," she said.
"This is in our community now, it's in our hospitals. If you're not vaccinated, please get vaccinated."
The long-awaited reopening of WA's borders last week means there is no longer any requirement for incoming travellers to quarantine.
But Premier Mark McGowan has begun serving a self-imposed seven-day stint in isolation after returning from Sydney, where he was required to give evidence in the Federal Court after being sued for defamation by Clive Palmer.
The premier has insisted upon quarantining in a serviced apartment to avoid any perception the border reopening date was chosen for his own benefit.
"He wants to set a good example," Ms Sanderson said.
"He's covering the cost out of his own pocket and he will be attending meetings (virtually) and managing the state as is appropriate."
