A new study by The University of Western Australia has revealed that South Australia’s harsh lockdown is likely to be the most effective strategy to contain and then reduce the spread of COVID-19.

Lead researcher Professor George Milne from UWA’s Department of Computer Science and Software Engineering said the study, published in medRxiv, showed an early and hard response to coronavirus outbreaks significantly reduced the spread of infection, and subsequent hospitalisation and mortality rates.

Results from this study reinforce and quantify the benefit of early activation of robust response measure to second and more COVID-19 infection waves”

Professor Milne

“Such measures are shown to significantly contain, then reduce, the epidemic growth rate and consequential pressure on health care resources.

“Results demonstrate how critical the timing of lockdown activation is. A slow response to rapidly growing case numbers allows the coronavirus to spread quickly within the population, before the introduction of more robust social distancing measures can take effect.”

Professor Milne said researchers identified a pattern in daily case number increases, its early exponential growth rate, which may be used to “trigger” strict lockdown introduction.

With Australia experiencing a second wave from June 2020 onwards, confined to greater Melbourne, initial social distancing measures failed to reduce rapidly increasing case numbers, he said.

“We conducted a detailed modelling analysis of this outbreak, together with an evaluation of the effectiveness of alternative response strategies, to provide guidance to countries experiencing second waves of virus transmission,” he said.

“Our study indicates that recent lockdown measures, such as taken in the UK, and in Melbourne in June/July, were activated too late, so lessening their effectiveness.

“We identified policy decisions by the Victorian Government that contributed to the initial failure in containing their second wave, evaluated alternative response strategies, and quantified their effectiveness in terms of reduction in case numbers.

“Our analyses confirm the need for strict lockdown measures to have been taken much earlier.”

Professor Milne said there was a significant challenge in responding to second waves of COVID cases, with governments hesitant to introduce hard lockdown measures given the resulting economic impact.

Professor Milne and his team conducted COVID-19 modelling for the State governments of Western Australia and Queensland.