As Western Australians wonder how the state's eventual border reopening might unfold, pundits often draw on the South Australian experience as the state with not only the most comparable population and density, but a COVID-free existence for major parts of the pandemic.
But just how well does this comparison stack up? And what bearing might the SA experience have had on the decision to indefinitely delay WA's February 5 border reopening?
COVID-zero SA opened with confidence
SA Premier Steven Marshall announced his plans on November 15, 2021, and South Australia tore down its borders on November 23.
"People want to come to South Australia and I think it's happy days for our state going forward," Steven Marshall said at the time.
That was 11 weeks ago and at the time, SA had zero active cases of COVID-19.
South Australians were 78 per cent double vaccinated, and booster shots were not yet available.
Thousands of people entered South Australia at its road borders and by flying into Adelaide.
Less than 24 hours later, South Australia recorded a positive case of COVID-19.
Omicron arrives after door flung open
Three days after South Australia opened, the World Health Organisation declared Omicron a variant of concern, citing fears over its high transmissibility and relative indifference to immunisation.
South Australia's Chief Public Health Officer (CPHO) even suggested closing the borders again, but it was decided against.
Case numbers bubbled away in SA and it reached 100 daily cases by December 20, and then things accelerated.
By Christmas Day there were more than 600 daily cases.
Come Boxing Day in South Australia, 40 aged care facilities had been listed as exposure sites, and 40 clients and staff in the disability sector had caught COVID.
On December 27, a little over a month after opening, South Australia reintroduced tough restrictions.
Home gatherings were limited to 10 people and hospitality venues restricted capacities to a four-square-metre rule indoors and a two-square-metre rule outdoors, and dancing was banned.
That same day, SA recorded its first COVID death since April of 2020.
2022 rings in SA's new Omicron reality
By New Year's Eve, the daily cases in South Australia had risen above 2,000 and two weeks later, the state had amassed almost 6,000 positive cases, its highest-ever tally.
On the very same day, January 14, the South Australian CPHO released the state's modelling based on the Omicron variant.
By Australia Day there were 287 people in SA hospitals with COVID-19, and 32 of those people were in ICU, with five requiring a ventilator.
The following day, SA recorded 13 deaths, seven in 24 hours and five after data from aged care facilities was reconciled.
Modelling released based on the Delta variant had previously predicted it would take 300 days for SA to see 13 deaths. When the SA border opened there had been four COVID-related deaths in the state for the whole pandemic.
Fast forward 11 weeks and there have been 149 deaths in SA and the state is dealing with 14,016 active cases. Numbers of daily cases have eased since that peak in January, but they have not once dipped below 1,000.
Was McGowan given the 'crystal ball' Marshall wished for?
The SA Premier, Steven Marshall, has regularly defended the opening of his state's borders saying Omicron was "unforeseeable".
"We could have said, 'Well look, we're going to keep it closed on the 23rd', if we had a crystal ball and we knew that something was coming the world hadn't even heard about yet," Mr Marshall said on December 27.
When Steven Marshall made those comments, his counterpart across the border, Mark McGowan, had perhaps the closest thing to a crystal ball – five weeks up his sleeve before WA's border was due to come down.
On December 13, the day Mark McGowan first announced the February 5 opening date, there were 1,023 new cases of COVID-19 nationwide.
On January 20, the day Mark McGowan told West Australians he had changed his mind and the border would not open on February 5, the country recorded 63,941 new cases in 24 hours. That same day there were 3,777 new cases in South Australia alone.
WA has recorded 2,186 cases in two years.
Advantages for WA as vaccination peaks
There is a myriad of reasons why SA does not provide a perfect comparison to WA.
When South Australia opened up, it had just under 80 per cent of its population double vaccinated whereas 94 per cent of West Australians are already double-dosed.
In the time since SA opened, vaccinations have also become available for children aged five to 11, and a third dose was rolled out to the general public.
Western Australia is likely to have more than 80 per cent of its population triple-vaccinated against COVID before its borders come down, compared with 0 per cent in SA when it first opened.
WA will also have stricter separation between the vaccinated and unvaccinated, having some of toughest vaccination mandates in the world.
The availability of rapid antigen tests is also likely to be another point of difference, assuming WA's orders arrive.
Other variables include the difference in the states' population sizes, the proximity to other capital cities, and the frequency of international flights arriving.
SA's hard line on public health restrictions
WA has already taken some lessons from the South Australian playbook, including a smartphone app for managing COVID cases at home.
But the Australian Medical Association in WA has been pushing for several weeks for WA to adopt the same strict social restrictions SA once had.
In pushing for these measures, AMA WA President Dr Mark Duncan-Smith has cited SA Health's Omicron modelling. He said there was little else to go on because, unlike South Australia, the WA Government refuses to release any Omicron-based modelling.
Mark McGowan has said on a number of occasions such restrictions have not been introduced yet because people will tire from restrictions if they are introduced too soon and all at once.
So it remains to be seen when or if WA will replicate the measures taken in SA.
Another point of difference in SA has been its persistence with a 10-day isolation period for COVID-positive people, although for close contacts in SA, the period is seven days.
WA clung to a 14-day quarantine period until this week but has now eased its isolation protocols even further than SA to seven days for close contacts and for COVID cases.
In South Australia, schools opened initially this year only to vulnerable students and children of essential workers.
WA 'easing in' with soft opening
The hard border remains firmly in place, but it has eased significantly in the past week to see many more West Australians allowed back into the state and quarantine periods halved.
About 12,000 people flew into Perth last weekend after exemption criteria were expanded.
And it is among these people, all in mandatory quarantine, that hundreds of positive cases have been recorded this week.
Mr McGowan pointed to these cases in defence of his hard border.
"With the massive spike in cases among returning Western Australians in the last few days, one could only imagine the kind of seeding event that could have taken place under the original plan – with far higher arrival numbers and no quarantine protocols," he said on Thursday.
"The decision to delay the full border opening was the right thing to do for the safety of the people of this state, it was about saving lives, saving jobs, and saving the economy."
Reopening falls short of expectations
Nikki Govan is the chair of SA Business and is a restaurant and hotel owner.
She said South Australia's opening ended up being far from what businesses had been hoping for and were excited about.
Ms Govan said her advice to WA businesses would be to do all they could to "beef up" staffing levels now, despite worker shortages
She said almost all sectors in SA struggled with staff off sick or isolating, but not many were picking up the virus at work.
Ms Govan said one of the big challenges was whether staff would do the right thing outside of work.
"They would go to a nightclub, they would become a close contact, and then they're wiped out for seven to 10 days.
"Say to your staff, what you do in your private time is obviously your own business, but please be considerate of what we've got going on as well."
Nikki Govan said looking back, many would have actually preferred SA to delay reopening.
"In hindsight, there are plenty of businesses in South Australia that would have liked to have been like Western Australia, just being open to within the state – particularly in tourism and hospitality," she said.
"I think it was probably sensible to defer that. Now having said, that there's a lot of the business community that are desperate to open up, not just to Australia, but also to internationals.
"I think this first deferral is good, but I suspect that any further deferrals are going to see the business community really, really struggling to get themselves back on."
She said more than anything, businesses needed certainty and that included having a date set for the border to open.
'The horse has bolted': Border closure now almost irrelevant
Biostatistician and epidemiologist from UniSA, Professor Adrian Esterman, said it was common for government messaging around COVID to be confusing.
"All governments have failed miserably to get good messaging to the general public, and that includes the WA government and all state and territory governments," he said.
"What the government needs to do, is give in simple terms what the modelling is based on, what's recommended by the modelling, and what the caveats are.
"And they never do that."
Professor Esterman had pushed for SA to delay its border opening, but he said he saw no need for WA's hard border to remain with Omicron already spreading through the state.
"There will be exponential growth, there's absolutely no question," he said.
"The issue is, with your current public health measures in place, and potentially other ones as well, and your very high vaccination rates – can you stop it from going up into the thousands?
"I don't think opening the borders would make much difference now, the horse has bolted, you've already got lots of local cases, they're only going to get more and more, I think it's almost irrelevant."
WA is dealing with unprecedented local transmission of COVID-19, with 51 cases recorded on Friday and although Saturday's figure was lower, testing rates were worryingly low.
At least one aged care home is included in the transmission sites.
The WA government has admitted it will not be able to eliminate the current outbreak of Omicron and it is expected cases will begin to rise dramatically by the end of the month.
While South Australia opened with zero active cases, WA currently has 482.
On January 20, Mark McGowan promised to spend a month reviewing WA's reopening date, and as the end of that four-week period rapidly approaches, he will be under increasing pressure to give West Australians some certainty.
