The Univeristy of Melbourne The Royal Melbourne Hopspital

A joint venture between The University of Melbourne and The Royal Melbourne Hospital


23 Aug 2021

Statement on the Doherty Institute modelling

The Doherty Institute understands how extremely challenging lockdown restrictions are for everyone.

There is light at the end of the tunnel – once we achieve 70%-80% vaccination we will see less transmission of COVID-19 and fewer people with severe illness, and therefore fewer hospitalisations and deaths. COVID-19 won’t go away but it will be easier to control in the future. These estimates come from the modelling work completed to date led by the Doherty Institute and commissioned by the Commonwealth Government to advise on the National Plan to transition Australia's National COVID-19 Response

This level of vaccination will make it easier to live with the virus, as we do with other viruses such as the flu. However, it won’t be possible to maintain a situation where there are no cases at all. The focus will shift to keeping the number of people going to hospital and dying at a minimum.

In an average year of influenza, we would roughly have 600 deaths and 200,000 cases in Australia. Any death is a tragedy, but our health system can cope with this. In the COVID-19 modelling, opening up at 70% vaccine coverage of the adult population with partial public health measures, we predict 385,983 symptomatic cases and 1,457 deaths over six months. With optimal public health measures (and no lockdowns), this can be significantly reduced to 2,737 infections and 13 deaths.

We’ve learned from watching countries that have removed all restrictions that there is no ‘freedom day’. We will need to keep some public health measures in place – test, trace, isolate and quarantine – to keep the reproduction number below 1, but as vaccination rates increase, we’ll be able to ease up further and it is unlikely that we will need generalised lockdowns.

Once we reach 70% vaccine coverage, opening up at tens or hundreds of cases nationally per day is possible, however, we will need vigilant public health interventions with higher case loads.

It might seem that these ‘test, trace, isolate and quarantine’ measures aren’t currently working – in New South Wales or Victoria. But they are. They are stopping transmissions and reducing the effective reproduction rate from 5 to closer to 1.3 in New South Wales. These measures will become more effective with more people vaccinated as vaccines also contribute to stopping transmission.

We are moving towards these targets at a rapid pace, but we need to keep supressing COVID-19 through public health measures while we work towards 70%-80% vaccination across the country. This will ensure we continue to keep the level of hospitalisations and deaths as low as possible to protect the community and prevent our healthcare system from becoming overrun.

The team of modellers from across Australia led by the Doherty Institute is now working through the implementation issues specific to the states and territories, specific populations and high risk settings.

We are moving towards better control of COVID-19 and a more stable future. We encourage everyone to stay vigilant, get vaccinated if you are eligible and take care of each other as we transition to living with COVID-19.

The Doherty Institute Modelling Report to advise on the National Plan to transition Australia's National COVID Response can now be viewed here.