Victoria could have eliminated Covid in six weeks by entering stage-four lockdown in July, analysis shows
Elimination of Covid-19 has been found to have been achievable in Victoria within six weeks had the state gone into stage-four lockdown with mandatory wearing of masks – but without curfews or 5km travel restrictions – immediately from 9 July, when there were 860 active cases of the virus in the state.
The modelling analysis published in the Medical Journal of Australia (MJA) on Monday also says it was a missed opportunity that “an expert advisory group on elimination was not convened, limiting the capacity for an optimal evidence-informed policy response”.
From 9 July, metropolitan Melbourne and the Mitchell shire re-entered stage-three lockdown. Victorians were told the measures would last six weeks. However, a more stringent stage-four lockdown was introduced to metropolitan Melbourne on 2 August, when department and hardware stores were closed, and curfew, travel limits and outdoor exercise limits were introduced. Regional Victoria joined the Mitchell shire in stage-three lockdown from 6 August. Masks were made mandatory in metropolitan Melbourne and the Mitchell shire from 22 July, and in regional Victoria from 3 August.
The MJA analysis, led by a professor of epidemiology at the University of Melbourne’s school of population and global health, Tony Blakely, found that had Victoria introduced a six-week stage-four lockdown with masks from 9 July statewide, elimination of the virus was possible. Their model did not include curfews or a 5km travel limit, but included a lockdown that saw schools, department stores and hardware stores closed, most people except essential workers working from home, and maskwearing made mandatory.
“Our work and that of others who have independently considered the alternatives consistently demonstrates that elimination was possible, and if achieved would have been optimal for health and for the economy in the long term,” the paper concluded.
The chances of success of the plan would be increased with “strong and decisive leadership with strategic clarity”.
“A clear set of targets for loosening of policies needs to be articulated, so citizens know what is likely to happen and when,” the paper said.
Blakely told Guardian Australia that eliminating community transmission of the virus in Victoria was now unlikely, but still possible with luck given the numbers have dropped so much in Victoria since Wednesday.
“If New South Wales numbers start to fall, then maybe, just maybe, elimination is worth a crack if NSW and Victoria get super lucky,” he said. “However, most of us think elimination is out of reach now in those states, but there is a small chance.”
In May, Blakely and his team estimated elimination of the virus in New Zealand to within a week of when it first occurred, and also predicted Australia was likely to experience a significant second wave under the then policy settings. Their paper published on Monday is based on the same modelling.
A professor of epidemiology at La Trobe University, Hassan Vally, said there was “a great deal of randomness or plain luck” involved with how things played out.
“I think what we are seeing in the different approaches to the pandemic and the success some countries have had without the need for lockdowns as strict as Victoria’s is that this is a complex problem and no one can be absolutely certain what the settings are that will achieve best outcomes,” he said.
“We will be debating this issue of what the optimal settings should have been one year from now, five years from now, and even 10 years from now. And we will obviously have better models and better analyses in the future as we learn more about Sars-CoV-2 and we obtain more data.”