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Victorian health authorities must be smarter about their approach to lockdowns when the next coronavirus outbreak inevitably emerges so that unnecessarily long and punishing COVID-19 statewide shutdowns are avoided.
That is the rising chorus of Australia’s leading infectious diseases experts, who say a complete rethink of coronavirus lockdowns is needed. Weary Victorians emerged from the state’s fourth hard lockdown on Thursday night, bracing themselves for at least another week of ongoing restrictions.
A deserted Melbourne during the most recent COVID lockdown.Credit:Justin McManus
Whether Victoria waited too long before declaring a lockdown to contain its latest spate of coronavirus outbreaks is a question that has weighed heavily on Professor Brendan Crabb.
“Theoretically, the answer might be yes,” the microbiologist and head of Melbourne’s Burnet Institute said.
“Lockdowns are an essential part of the pandemic-control tool kit because they work. Nobody wants to use them. You desperately don’t want to use them. But, ironically, if you want to use them smartly then you have to pull the trigger early, you have to act incredibly early on in an outbreak.”
But closing business, schools and confining millions of people to their homes on a partial judgment call is understandably contentious because there was no denying it caused “tremendous collateral damage”, Professor Crabb said.
“It is an extremely tricky space and you need smart and pretty brave authorities to be able to make those calls quickly and strategically because, of course, it is painful for people and there is no question about that,” he said.
“We need to look after those who suffer the most from it. But it comes with a big prize, which in Australia, is this remarkable COVID zero that we have and its associated economic benefit … and even civil society benefit.”
Professor Brendan Crabb, director of the Burnet Institute in Melbourne. Credit:Burnet Institute
Deakin University’s chair in epidemiology, Catherine Bennett, said the data was increasingly pointing to snap lockdowns being required only in extreme circumstances, when there were several positive cases in the community that could not be linked.
Recently, experts crunched the numbers on 17 COVID-19 outbreaks in Australia since December, finding only six triggered snap state lockdowns, six were managed by gathering restrictions and five by contact tracing only.
The analysis found that four of the six lockdowns failed to detect further cases not already isolated through contact tracing. Only the northern beaches outbreak in Sydney and the Princess Alexandra Hospital outbreaks provided the exception to the rule.
Professor Bennett said Victoria relied heavily on long lockdowns last year to crush the virus when the state’s contact tracing system buckled. But systems to trace and isolate positive cases had substantiality improved since.
Rather than continually going into “blanket lockdowns”, Professor Bennett said the state government must scrutinise its data to improve how it handles future outbreaks.
“It not about patting ourselves on the back because we eventually go to zero cases after weeks or 112 days of lockdown,” she said.
“It is examining the incredibly detailed, rich data we’ve got based on this recent outbreak. It’s questioning whether we had gone into lockdown in week one rather than holding off and stepping up interventions like masks indoors. Would that have changed the outcome?”
The new delta variant is more transmissable and causes greater hositalisations and emergency admissions, says Professor Catherine Bennett, chair of epidemiology at Deakin University. Credit:Jason South
The epidemiologist is still perplexed as to why Melbourne was plunged into a short five-day lockdown for the Holiday Inn outbreak in February, which led to 24 cases of coronavirus, when there was no indication of community transmission.
The decision to plunge Victoria into a five-day stay-at-home order was made five days later, after 13 cases with known sources had been detected in the community.
A month earlier, the Black Rock cluster seeded in a super-spreading event at a Thai restaurant swelled to 31 cases, but it was contained swiftly without a lockdown through contact tracing, testing, mandating face masks and limiting gatherings.
“Why go lockdown for the Holiday Inn if we didn’t need to do it for Black Rock? It doesn’t make any sense,” she said.
Adrian Esterman, from the biostatistics and epidemiology department of the University of South Australia, said the countries willing to use lockdowns early end up having vastly fewer lockdowns than a places that reject them.
The United Kingdom, which rejected the notion of lockdown, is only just emerging from a five-month lockdown, spurred on by the significant success of its vaccine program, after being slow to enforce restrictions.
“For every day you start a lockdown earlier, you lose three days at the end of it,” Professor Esterman said.
“But it is an extremely hard to make a call early because the difficulty is it can take three or four days for authorities to see what is happening. If there has been an exponential growth of cases … by then you’ve missed the window for a short, sharp lockdown.”
Business leaders last month predicted Victoria’s most recent lockdown would cost more than $1 billion a week.
“Instead spending billions of dollars on lockdown, why don’t we spend a billion on building quarantine facilities in each state because that is where every single leak is coming from,” Professor Esterman said.
To curb leaks from hotel quarantine, Professor Crabb wants a national task force on airborne transmission set up to prevent repeated virus leaks from hotel quarantine, which have hit more than 20 cases in the last year.
Vaccine coverage, variants of concern that continue to emerge and the scale of the overseas epidemic will be crucial factors in determining when we can end lockdowns and rely on simple public health interventions such as face masks.
Epidemiologists warn lockdowns remain on the horizon for many months to come until Australia can build up enough immunity through vaccinations.
But Professor Crabb said lockdowns must be called as early as possible and kept short and sharp: no longer than two weeks.
“We might just have to face the facts that we may not be completely finished with them just yet,” Professor Crabb said. “For the next six to nine months we are just as susceptible to a decent outbreak as ever and to stop it we have to use the tools we have previously.“
Until the day comes when lockdowns are no longer needed, Professor Crabb said smarter mitigation measures must be used to keep schools open during outbreaks as experts warn frequent classroom closures are causing more long-term emotional harm to children than the virus.
Fast-tracking vaccinations for teachers is essential, but so are ventilation checks and moving high-risk activities outside, he said.
Ultimately we must learn to live with COVID-19 in the years to come, even after high levels of vaccination have been achieved.
Melbourne University epidemiologist Professor Tony Blakely is one of a growing number of infectious disease experts who say it is increasingly unlikely Australia will reach herd immunity.
“COVID never plays simple,” Professor Blakely said. “This black-and-white concept of magic herd immunity, I suspect we’ll never achieve it because variants will keep coming up and popping up.”
Herd immunity occurs when a high enough proportion of the population is vaccinated against a disease or has been infected with a disease and developed antibodies against it, preventing the virus from transmitting widely.
Despite this, he predicts Australia will still open its borders next year.
“It is going to be bumpy,” Professor Blakely said said.
“There will be people getting infected. There will be morbidity and unfortunately there will be some deaths. But when we open up to the rest of the world, it really is moot what role lockdowns will have and it will depend on how much infection we allow in at any one point in time.”
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