Western Australia has held off on bringing back a hard border to Victoria, where a cluster of coronavirus cases has prompted a five-day lockdown.
Victoria's fifth lockdown since the start of the pandemic will begin at midnight on Thursday amid concern about a growing outbreak of the Delta variant.
Two new local cases were recorded earlier in the day, 24 hours after WA reclassified Victoria as a "low risk" jurisdiction under its controlled border regime.
Travellers who have been in Victoria must self-quarantine for 14 days upon arrival at a suitable premise and get tested twice during that period.
The change was enforced with immediate effect, catching some passengers aboard flights from Melbourne unaware.
NSW and Queensland are already categorised as medium-risk states, effectively locking out any non-exempt travellers.
Chief Health Officer Andy Robertson had warned Victoria could be placed in the same category if there was an escalation of its outbreak.
"It will really depend over the next 24, 48 hours as to whether the spread has been contained or whether it is more widespread," he told reporters on Wednesday.
About 4200 people had arrived in WA from Victoria in the five days prior to the tightening of the border.
Thursday night's AFL game between Geelong and Fremantle at Optus Stadium is set to go ahead with no crowd restrictions.
WA this week further tightened exemptions for travellers from NSW, including those granted on compassionate grounds.
The latest travel advice states that WA residents wanting to enter from NSW "are not guaranteed right of entry" and must demonstrate extenuating circumstances.
Dr Robertson said they could include people who had very ill or dying family members or a spouse who was about to have a baby.
He warned there was no prospect of the restrictions being eased anytime soon.
"Given we also require 14 days of no community cases before we can consider getting back to a very low risk, I think that would probably take us through August into September," he said.
WA recorded no new cases on Thursday. Seven active cases are being monitored.