Health

Junk Explained: What Does COVID Modelling Mean And Why Is Everyone Talking About It?

Australia's path out of lockdown is being dictated by certain predictions - and not everyone agrees with them.

by Edwina Storie  26 August 2021

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You might have noticed there’s a lot of chatter about ‘modelling’ recently. Experts and politicians trying to plan how and when we’ll come out of lockdown, and what that means in terms of the number of lives lost, people in hospital, and daily case numbers..

Last year we were going for ‘COVID zero’, and states like Western Australia and Queensland still seem to be keen on maintaining that paradisical vision into 2021 (good for them, it looks great there).

But the reality is markedly different in other states, and across the world. This week, NSW’s chief health officer Dr Kerry Chant told reporters that “the world is grappling with how we coexist with COVID”, and Prime Minister Scott Morrison commanded that we have to learn to live with the virus. According to Morrison, hitting the 70 and 80 percent vaccination rates is the key, and that is based on predictions from the Doherty Institute. (He then went on to compare coming out of lockdown like that animated film The Croods, which…sure.)

Recently, more modelling has been released by different scientists, and the predictions of death and daily COVID cases are scarily different. Like, 20,000-plus deaths different, along with 270,000 cases of long COVID. So what does it all mean? What is the Doherty Institute? And will the quokkas in WA be shut off from the rest of Australia forever?

The National Plan

Back in July, the states and territories came together for a National Cabinet meeting to agree on a way of opening up the country, based on the modelling it had requested from the Doherty Institute. And this modelling would be used in conjunction with the Federal Government’s Four Phase plan.

The Doherty Institute, its full name being the [very respectable] Peter Doherty Institute for Infection and Immunity, is a world-leader in understanding and treating infectious diseases. They’ve predicted what would happen in the first 180 days of moving from Phase A (where we currently are — suppressing the virus) to Phase B (minimising fatalities and hospitalisation) — if we opened up at 50, 60, 70 and 80 percent of people over 16 years vaccinated (that’s 65 percent of the entire population). The modelling was done on the idea that there were 30 cases circulating in the community as we moved from Phase A to Phase B.

The modelling considers how many of us are vaccinated, and in which order, along with the efficacy of the TTIQ tactics we’ve come to know so well — test, trace, isolate, quarantine.

It says that “even at very high levels of vaccine uptake (80 percent or above), suppression of epidemic growth below the critical reproduction number of one required to attain ‘herd immunity’ was unlikely.” But vaccination will decrease the disease severity for people who are vaxxed. Therefore, Australia will move to “manage COVID-19 consistent with public health management of other infectious diseases”.

The idea is to shift away from COVID Zero and toward keeping deaths and hospitalisations at a minimum, like we do with flu. Being more accustomed with COVID is something we’re going to have to get used to as we move to open up.

Source: Doherty Institute

The Doherty modelling states that when we reach 70 percent, we can open up at dozens or hundreds of cases nationally a day, but “will need vigilant public health interventions.”

This week, Scott Morrison called a grand press conference and gave a clear message that we need to stick to the National Plan of opening up. But the states are tense as many go through their own COVID crises, and some have distanced themselves from the Doherty model Morrison is employing.

Victoria is still going for COVID Zero, and Premier Daniel Andrews said that the Doherty Institute numbers are based on “very few cases” circulating. “That’s why we’re working so hard to get to that point, because the modelling that 70 will work and 80 will work, that is to be open and in a very different world by the end of this year,” he said last week. “It gets harder to do that if there’s cases running wild.”

The leader of the Doherty Institute Professor Sharon Lewin refuted this, clarifying that no matter what number of cases you start at the rise of the cases will go at the same rate when we have that level of vaccination.

With 70 percent vaccination you will get “hundreds of thousands of cases, even starting from 30”, but the rates of hospitalisation and deaths will be greatly reduced.

“Whether you start at 30 cases or 800 cases you can still open up safely [with vaccinations],” said Professor Lewin on The Drum this week. The big thing about moving from moving from Phase A to B means we no longer aim for zero cases — track and trace then becomes less motivated by zero COVID, she added.

What Do Other People Reckon?

Then, on Wednesday, researchers from Australian National University (ANU), University of Western Australia and the University of Melbourne released different modelling that said the current national plan “puts too many lives at risk… It’s simply too dangerous to treat COVID-19 like the flu.”

Their modelling, which has not been peer-reviewed, predicts that when 70 pecent of Australians over 16 years of age are fully vaccinated (plus a 95 percent vaccination coverage of people 60-plus), “there could eventually be some 6.9 million symptomatic COVID-19 cases, 154,000 hospitalisations, and 29,000 fatalities,” says Professor Grafton from ANU. “And assuming 80 percent vaccination coverage for only those over 16, as per the National Plan, there could be approximately 25,000 fatalities and some 270,000 cases of long COVID.”

“The latest research models total cumulative deaths over a longer time frame during Phase D of the national plan — when no restrictions remain,” The Guardian noted.

This modelling recommends vaccinating kids and teens, and giving everyone booster shots. It would rather see 90 percent of people vaccinated before letting COVID rip. Professor Grafton said it was a “real problem” to exclude five million people by setting vaccination targets based only on the population aged 16 and over, when Delta was also transmissible among children. When pressed by the Guardian, the Doherty Institute stood by its modelling.

In Victoria, up to Wednesday 18 August, 45 percent of active COVIDcases in Melbourne kids and teenagers. That said, Scott Morrison has discussed people 12 to 15 having access to the vaccination before the end of the school year, if agreed upon by National Cabinet.

There Are Some Big Unknowns

What this all ultimately depends on is how much we’re prepared to live with A) restrictions, B) COVID, and C) deaths. Plus, the efficacy of our TTIQ. The more vaccinated we are, the fewer deaths we have, but that would also require gritting our teeth for longer while everyone gets jabbed (assuming they want to…please get jabbed).

Morrison is keen to get on the road (despite regrettably saying “it’s not a race“) while premiers like Dan Andrews are understandably concerned about the capacity of the healthcare systems they manage — they’re flying in 350 medical staff from overseas to help out.

There are thornier questions still, such as how many COVID-related deaths are Australians prepared to tolerate? A big thing to consider, too, is that we won’t be seeing any Freedom Days. Life may still include lockdowns if our TTIQ can’t hold up in Phase B.

Currently, 30-ish percent of us are fully vaccinated. (Which feels damn good considering we were trailing at the bottom of the OECD just two-ish months ago.) The one thing everyone can agree on right now is that vaccinations are the way out. So rally your mates, and pull up your sleeve, because we all need to move toward a “normal” life, which seems so very foreign right now.