Wednesday's tally marks the first time WA has reached triple figures for locally-acquired COVID-19 infections. The state had recorded just 14 local cases a week earlier.

There were also 13 new travel-related infections but WA Health did not indicate how many new cases had been infectious while in the community.

WA's justice department confirmed a guard at the privately-operated Acacia Prison had tested positive after becoming unwell on Tuesday, having returned to work that day from a three-day break.

One staff member has been identified as a close contact and eight guards who worked on shift in the same unit are isolating and being tested.

"No prisoners have been identified as close contacts," the Department of Justice said in a statement.

"A forensic clean of the unit and high traffic areas is being conducted.

"Preliminary advice to the department indicates the infected officer complied with all COVID-19 safety requirements whilst at the prison yesterday."

The medium-security facility northeast of Perth is operated by Serco and has the capacity to house just over 1500 prisoners.

Premier Mark McGowan described the exposure as concerning.

"That's why we've mandated vaccines for guards and we strongly encourage prisoners to get vaccinated," the premier told reporters.

A further two residents at Juniper's Cygnet residential aged care home in Bentley have tested positive.

Ten residents and four staff members have so far been infected.

Juniper chief executive Chris Hall said the Australian Defence Force was assisting with logistics.

"We know this is a difficult time for residents and their families. We are doing all that we can to keep them informed and assist families and loved ones to stay connected with residents through the use of technology," Mr Hall said.

Ten residents and two staff have tested positive at Brightwater Care Group's The Cove home in Mandurah, while one staff member was infected at the nearby Coolibah Care facility.

At least 32 schools have been exposed during the Omicron outbreak.

Mr McGowan dismissed suggestions the hard border had become redundant despite local cases easily outnumbering those related to travel.

He said there was still a need to improve the third-dose vaccination rate which has climbed above 53 per cent and is likely to surpass 80 per cent next month.

"What we are doing is saving lives and saving jobs at the same time," he said.

The premier has promised an announcement on easing the border restrictions will be made this month.

WA had been due to fully reopen on February 5 before Mr McGowan backtracked, citing a low booster rate and high rates of Omicron-related hospitalisations and deaths in the eastern states.

About 30,000 people have returned to WA to reunite with loved ones since the government softened the border rules earlier this month.

Mr McGowan has asked the City of Perth for assistance in moving on a few dozen anti-vaccine protesters who have attempted to camp at Langley Park.

Legalise Cannabis MP Sophia Moermond was suspended from parliament on Tuesday after the government used the first sitting day to pass a motion requiring members to provide evidence of their vaccination status.

Upper house MPs were required to prove they had received their first and second doses by January 31 and their booster by May 6.

They could alternatively provide evidence of a valid medical exemption.

Ms Moermond - who refused to disclose her vaccination status - likened vaccine mandates to "medical apartheid".

Australian Associated Press