Suppression Vs Elimination: The facts, myths and strategies for both - as Australia's states continue to bicker over borders

Australia's infectious diseases experts and political leaders can be divided into two broad camps when it comes to tackling the pandemic.

January 12 marks the first anniversary of China sharing the genetic sequence of COVID-19, after the previously unseen type of coronavirus was discovered in a Wuhan market.

Less than two weeks later, a man from the city brought the first case of the disease to Australia.

Since then, Australia's state governments have divided along suppression versus elimination factions when it comes to tackling the virus, with Liberal leaders mainly preferring a moderate approach and Labor premiers imposing more hardline measures. 

The suppression strategy opposes city-wide lockdowns, instead preferring an emphasis on contact tracing, localised containment strategies, crowd number restrictions and open state borders. 

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Australia's infectious diseases experts and political leaders can be divided into two broad camps when it comes to tackling coronavirus. Pictured is a panic-buying queue at Gasworks Plaza at Newstead in Brisbane's inner-north

With the coronavirus pandemic expected to persist throughout 2021, this school of thought argues for a longer-term approach where the public can more easily live with restrictions on everyday life - accepting that outbreaks will most likely reappear even as a vaccine is rolled out.

New South Wales Premier Gladys Berejiklian has mainly practised the suppression strategy where a balance is struck between reducing the viral spread and minimising harm to the economy and jobs.

For most of the pandemic Prime Minister Scott Morrison, another Liberal leader, has broadly favoured this approach with open state borders.

This is despite announcing a national lockdown in late March last year and the biggest debt-fuelled spending since World War II to compensate business owners and workers for business closures. 

The other school is the elimination strategy favouring wider and stricter lockdowns to completely eradicate the virus - arguing Covid is too deadly to live with.

Despite referring to Victoria's approach as 'aggressive suppression', Labor Premier Daniel Andrews's government brought in draconian lockdown measures akin to those used by elimination strategists.

From early August until late October, Melbourne's five million residents endured Stage Four restrictions that banned them from leaving home, apart from buying groceries or medicines, and only allowed one hour of exercise a day outside the home.

Victoria has accounted for 90 per cent of Australia's Covid deaths - with 820 fatalities out of 909 nationwide - following a hotel quarantining failure in July.

This saw a daily case count of 723 on July 30, before a horror month where daily increases were consistently in the hundreds.

As of Boxing Day, however, the state had recorded 57 days of no community transmission only to record three new cases just four days later, sparking a New Year closure of the border with NSW. 

New South Wales Premier Gladys Berejiklian has mainly practised the suppression strategy where a balance is struck between reducing the viral spread and minimising harm to the economy and jobs

Queensland's Labor Premier Annastacia Palaszczuk, another practitioner of elimination-style methods, imposed a three-day lockdown on Friday last week after just one person, a cleaner in hotel quarantine, caught the new, more contagious UK strain.

The two Covid factions

SUPPRESSION: An emphasis on contact tracing and a preference for localised instead of city-wide lockdowns so less harm is done to the economy

ELIMINATION: A focus on achieving 28 days with no locally-acquired cases with a preference for city-wide lockdowns to stop the spread of Covid 

South Australia's Liberal Premier Steven Marshall in November imposed a six-day lockdown after Covid was traced to a pizza shop, but the restrictions banning even outdoor exercise ended after three days.

Tasmania's north-west was locked down in April but Liberal Premier Peter Gutwein has yet to lock down all of Hobart to contain a new outbreak, opting instead for island state border closures.

Western Australia's Labor Premier Mark McGowan has been even more hardline on border closures, banning entrants from Queensland, Victoria and NSW.

On Monday, he doubled down on his stance, declaring WA would remain closed to Queensland until February, and ridiculed the NSW suppression strategy approach.

'The idea you tick along with the virus and somehow that is a better model is wrong and I just urge the New South Wales government and people in New South Wales to look at what other states and territories are doing in order to crush and kill the virus,' he said.

For the elimination school, success is regarded as going for 28 days with no new locally-acquired case or community transmission.

NSW, which has always opted for a suppression strategy, reached the other faction's goal on November 23, before a Northern Beaches outbreak in the second week of December. 

No state leader is openly declaring themselves to be part of on the elimination camp except WA's Mr McGowan, but the evidence in clear on their preferred method. 

Suppression strategy 

Australian National University infectious diseases expert Professor Peter Collignon, an advocate of the suppression strategy, said existing Covid measures had eliminated earlier strains of the disease, only for returning overseas travellers to recently bring in new mutations from the UK and South Africa.

The Canberra-based physician said the social and economic costs of city-wide lockdowns could not be justified when there were so few new daily cases in Sydney, Melbourne and Brisbane in early 2021.

Australian National University infectious diseases expert Professor Peter Collignon, an advocate of the suppression strategy, said existing Covid measures had eliminated earlier strains of the disease, only for returning overseas travellers to recently bring in new mutations from the UK and South Africa

'Lockdowns have got a lot of social and economic impacts and really the question is when you should do them, weighing up against the cost,' he told the ABC's 7.30 program.

Professor Collignon argued Brisbane's recent three-day lockdown, covering last weekend, was ineffectual because COVID-19 typically had a five-day incubation period - the time from being infected and showing symptoms.

Queensland's Labor government placed greater Brisbane's 2.5million residents into lockdown from Friday until Monday after a coronavirus quarantine cleaner working at the Hotel Grand Chancellor contracted the disease.

But under the lockdown, based on one infection of the UK strain, people could still travel to work, which Professor Collignon pointed out mean colleagues of this cleaner continued travelling on public transport.

A Covid vaccine is being rolled out in Australia from mid-February but Professor Collignon argued coronavirus still linger for another two years, as travellers returned home, which meant the public had to be able to live with containment strategies. Pictured is a giant QR code in Perth on December 5, 2020

'So unless they were told specifically not to leave home, they would've been travelling anyway,' Professor Collignon said.

'So I'm not actually quite sure what the additional benefit from the lockdown in Brisbane was, compared to the standard, where you just do contact tracing, testing, and keep everybody who is a close contact within quarantine in their own home for up to 14 days, rather than doing it for the whole city.'

A Covid vaccine is being rolled out in Australia from mid-February but Professor Collignon argued coronavirus could still linger for another two years, as travellers returned home, which meant the public had to be able to live with containment strategies.  

Sydney's Northern Beaches (Avalon pictured) was locked down before Christmas as part of a suppression strategy of localising containment measures

'We are going to have to live with this for another year, or even two years with restrictions,' he said.

'So we need to do what is sustainable, consistent, predictable otherwise we'll have problems with people complying, I think.'

Elimination strategy 

More epidemiologists tend to favour the more hardline elimination strategy, which New Zealand Labour Prime Minister Jacinda Ardern's government has successfully implemented, with just 25 Covid deaths or just five per million.

More epidemiologists tend to favour the more hardline elimination strategy. Professor Michael Toole from Melbourne's Burnet Institute said broader lockdowns to eliminate Covid were justified

In the ABC debate, epidemiologist Michael Toole from Melbourne's Burnet Institute said broader lockdowns to eliminate Covid were justified, considering Sydney had recorded clusters more than 50km apart from Berala in the city's west to Avalon on the Northern Beaches. 

'People have described that as living with the virus, but I think that has quite a heavy social and economic cost,' he said. 

'The virus is still all over greater Sydney.'

Professor Toole argued a short, sharp lockdown across greater Sydney before Christmas, instead of just on the Northern Beaches, would have prevented Covid

'Just back to whether we could have implemented a broader lockdown in greater Sydney back in mid-December, there's no reason to believe that lockdown would still be in place because it could have and probably would have prevented spread to Erskineville, the CBD, Paddington, Croydon, Berala, and now Mount Druitt,' he said.

Both sides of the debate at least agree on the need for hand sanitiser and social distancing.

In Australia at least, state governments from both persuasions have also mandated face masks on public transport and in shopping malls, with NSW last week copying Victoria's approach during the lockdown.