Western Australia will close its border to South Australia and expand its coronavirus vaccination rollout which is the worst-performing in the nation.
Premier Mark McGowan says the hard border will come into effect from midday on Thursday, locking out any travellers who do not have an exemption.
WA has already closed its borders to NSW, Victoria and Queensland as the eastern states deal with outbreaks of the highly transmissible Delta variant.
"The whole country bar here, Tasmania and the Northern Territory has cases in the community," Mr McGowan told reporters.
"It's a very worrying time and we're going to do everything we can to keep it out."
A flight from Adelaide carrying 87 passengers was due to arrive in Perth later on Thursday after the hard border comes into effect.
About 12 per cent of West Australians aged 16 and over have received their first vaccine dose, the lowest rate of any state or territory.
With WA now having received additional supplies of the Pfizer vaccine from the Commonwealth, Mr McGowan has announced an additional 10,000 vaccination bookings per week will become available from the end of July.
A new mass vaccination clinic will open at the Perth Convention Centre from August 16, while another will open in Midland in Perth's east from September to replace the Redcliffe clinic.
Two new regional clinics will open in Busselton and Manjimup.
WA will also trial a walk-in program for people to receive their first doses at the Claremont Showgrounds during September's Perth Royal Show.
"Our aim is to make vaccination as accessible as possible for those who haven't yet had their first dose," Mr McGowan said.
People aged in their 30s are encouraged to register their interest but are not currently able to make appointments.
It is hoped WA will have sufficient supplies of the Pfizer vaccine to be able to open up bookings to anyone aged over 16 by September.
The state government wants 80 per cent of eligible adults to have at least had their first dose by the end of the year.
Mr McGowan said WA's isolation had shielded it from the worst of the pandemic, which may have made some people complacent about getting vaccinated.
"I understand some people might be hesitant ... but the threat is real," he said.
"Look at most of the nation now under lockdown."
Almost 80 per cent of over-70s have received at least one dose of a coronavirus vaccine and about a third are fully vaccinated.
The premier has urged the federal government to improve the rollout in aged care, saying the vaccination rate was high for elderly residents but lagging for workers.
WA recorded no new cases on Thursday. There are 15 active cases, including 10 crew members of the BBC California vessel docked in Fremantle.
Australian Associated Press