West Australians aged 30 to 49 will be eligible to receive the Pfizer coronavirus vaccine from Thursday, Premier Mark McGowan has announced.
Bookings are now open for over-30s at state-run COVID-19 vaccination clinics.
Mandurah and Pinjarra residents in this age bracket still need to travel at least 43km to receive the vaccine, with the closest clinics in Kwinana and Bunbury and the biggest clinic Claremont Showgrounds which will offer Pfizer and AstraZeneca jabs seven days a week.
At the time of publication, the soonest available date was on June 22 at both locations.
The health department has advised there are no plans for closer clinics but that mobile clinics would also make their way through the state's regional areas.
The eligibility extension comes after national cabinet last week agreed to expand the vaccine rollout to people aged 40 and over.
"In Western Australia, we've decided to take it further," Mr McGowan told reporters on Tuesday.
"This is a very significant expansion in our vaccination program. This will mean that far more West Australians can get vaccinated."
The rollout will also be expanded to include Aboriginal and Torres Strait Islander people aged 16 and over.
People aged 50 and over will continue to receive the AstraZeneca vaccine.
The premier said capacity at state-run clinics in Claremont, Joondalup, Kwinana, Redcliffe and Bunbury would vary from 700 to 2000 appointments per day.
He called on the Commonwealth to ramp up supplies of the AstraZeneca vaccine to GPs and help ensure pharmacists could administer jabs.
Mr McGowan also stressed that both vaccines had been found to be safe and effective.
Health Minister Roger Cook said the 30-49 cohort represented a "substantial" proportion of the state's adult population. He said WA had about 150,000 vaccine doses in stock, including more than 107,000 Pfizer doses.
A further 1.2 million doses are expected to arrive over the next eight weeks.
Mr Cook said the state had felt the national rollout was proceeding too slowly.
"Australia has been a leader in terms of its management of COVID-19 but we are a lagger when it comes to the vaccination component of our response," he said.
"So we wanted to take an aggressive stance ... we're determined to build momentum on this vaccination program."
About 60 per cent of people aged over 70 in WA have had their first dose but that number drops to 37 per cent for those in their 60s.
Just 25 per cent of people aged 50-59 have had their first dose.
"People often ask me 'when will we be able to travel again? When will we end the lockdowns?'," Mr Cook said.
"And the answer is simple: when we get vaccinated. Every person that gets the jab takes us one step closer to meeting these dual goals."
The premier said he hoped expanding the rollout would create a "snowball effect" which would help to address vaccine hesitancy.
"I'm very hopeful this is the light at the end of the tunnel ... that by the end of next year, or early part of the new year, we have the overwhelming majority of West Australians vaccinated," he said.
KWINANA: Tenancy 1& 2 46 Meares Avenue, Open 8:45am - 3:15pm Tue-Thu
CLAREMONT SHOWGROUNDS: Tom Wilding Pavilion, Gate 8 off Ashton Avenue, Open 9am - 3:15pm Sun, 8:30am - 4:30pm Mon, 9am - 3:15pm Tue-Sat
BUNBURY: Homemaker Centre Building 2E 42 Strickland St, Open 8:30am - 3pm Tue-Thu