Tony Blakely
If COVID-19 were allowed to spread unchecked, it would devastate Australian society. My modelling suggests that Australia could get as many as 400,000 to 600,000 infections a day at the peak – translating to about 150,000 to 200,000 symptomatic cases a day. There’s no way we can let the numbers get that high. It would be absolute carnage.
The chance of Australia locking down society, similar to measures in Italy, France and Spain, grows higher every day – and indeed is now happening in New South Wales and Victoria, it appears. But will our government seriously consider banning people from going to restaurants, cafes and pubs? If you’d asked me that question a few months ago, I would have said ‘No way!’.
If cases can be managed over the longer term, sufficient ‘herd immunity’ will eventually develop. That might happen even before a vaccine becomes available.
The intensity of our interventions before a lockdown was about right if society’s goal is ‘flattening the curve’. In a couple of weeks’ time, with more knowledge of what’s working elsewhere, and as the caseload starts to pick up, we’ll need to turn on more interventions to try to slow the increase.
A lockdown now in Australia suggests that either: the government is going too early to flatten the curve, and that it will just intolerably push the epidemic out to the end of the year or even next year; or that its goal is now eradication (as in Wuhan) and to keep Australia’s borders closed until a vaccine is available. There are good arguments either way – what we need now, though, is more clarity and honesty from our leaders as to what their goal is.
More interventions now might simply shift the peak further into the future and mean that society has to tolerate current impositions for longer. It’s a delicate balancing act. Mandated measures to flatten the curve will need to be reviewed constantly; they might need to be adjusted according to the load on the health system.
Another approach (within the ‘flatten the curve’ option, not the ‘eradication’ option), with a reasonable amount of good sense behind it, is being mooted in the UK: the canary in the coalmine being the number of people admitted daily to intensive care units (ICUs) – say 300 to 400 people, using Australia as an example.1 At that point, the system can no longer cope. So back comes containment or suppression, with everyone in lockdown (or whatever we learn is sufficient to slow the flow) for a week or however long. Given the delay in presentation, this pulse tightening would need 7–10 days before the expected ICU threshold is used, requiring good metrics and models.
Once we’re back to 200 or so people going into the ICU, we relax a bit (as the numbers will still track down a bit more until the new infections manifest as cases). There might be this ‘on–off, on–off’ way of managing – but perhaps better than sets of rules that hold in place for a couple of months.
It must be emphasised that the above option applies if we are actually pursuing the goal of flattening the curve. If we are to be audacious and aim for eradication and keep borders shut for a year or more, then it is full gas now for three months or so.
We might be able to develop ‘sentinel indicators’, like the numbers going to ICUs daily, and adjust our actions accordingly. However severe the restrictions on daily life, the government has made it clear that people should be prepared for at least six months of a radically different lifestyle.
That is likely to change our society in profound ways. It will be a major shock to society, but innovation will come out of this. We’re seeing a massive shock to the system. We’re going to gain new norms. This will see us behaving quite differently in the long term. Don’t throw that party. See your family, see your loved ones, bond with them, but in smaller numbers.
Tony Blakely is a Professor of Epidemiology at the University of Melbourne School of Population and Global Health and an Affiliate Professor of Health Metrics Sciences at the University of Washington Institute for Health Metrics and Evaluation.
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