A decision back in July could have seen Victoria eradicate COVID-19 and likely move out of lockdown faster, according to new modelling.
Analysis of modelling of Victoria’s coronavirus crisis suggests that elimination could have been achieved across the state if the government had immediately implemented stage 4 lockdown from July 9.
Analysis of the modelling found that elimination was possible for Victoria, adding that if it was achieved it “would have been optimal for health and for the economy in the long term”.
The first cases linked to Victoria’s second wave were detected in late May in early June, with the true extent of the new outbreak becoming apparent in the weeks following.
As a result of the wave of new infections, metropolitan Melbourne and the Mitchell Shire were sent into what was meant to be a six-week stage 3 lockdown on July 9.
However, cases continued to rise, prompting the tougher stage 4 lockdown to be introduced for Melbourne on August 2 and regional Victoria placed in stage 3 lockdown from August 6.
Stage 4 lockdown saw most things apart from essential businesses shut, a night time curfew imposed, a 5km travel radius introduced and strict rules around being in public put in place.
Masks were also made mandatory for everyone in Victoria, apart from those with a medical exemption.
The research paper examined three modelling scenarios and analysed how Victoria would have fared under each approach.
The first was a standard approach which was equivalent to keeping stage 3 lockdown but without masks, then there was a standard approach with mask use at 50 per cent, followed by a stringent approach with masks at 50 per cent and finally a stringent approach with mask use at 90 per cent.
The final approach was the most similar to the stage 4 lockdown introduced in Melbourne, except without the curfew or 5km travel restrictions.
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The analysis found that under the “standard” policy approach, which is what was first implemented in Melbourne on July 9, there was “no chance” all infected people would be cleared of the virus by the time the six-week stage 3 lockdown ended.
The modelling also predicted that there was a zero per cent chance of achieving elimination by the lockdown deadline with the “standard with masks at 50 per cent” approach.
The probability for elimination was slightly higher for the “stringent with masks at 50 per cent” approach, with 4 per cent chance of elimination.
The approach most similar to stage 4 lockdown was the most promising, with the “stringent with masks at 90 per cent” showing a 30 per cent possibility of elimination after six weeks.
Looking at the probabilities of the last actual virus infection occurring by August 19 when the six-week lockdown would end saw the figures become significantly more promising.
This change saw the probabilities put at 0 per cent, 1 per cent, 45 per cent and 90 per cent respectively.
Researchers concluded that had the decision been made to go into a form of stage 4 lockdown, even without the curfew and travel restrictions, then it was possible Victoria could have achieved elimination.
Undertaking simulation modelling of SARS-CoV-2 policy options is challenging and the uncertainties are still considerable even when using the best estimates available,” the paper stated.
“Nevertheless, our results lend weight to the proposition that elimination was achievable if Victoria had gone into stage 4 lockdown with mandatory wearing of masks immediately from July 9.”