“But as we know the virus does not stop for anybody, and doesn’t stop for any business, it’s our job now to ensure we follow all those chains of transmission and run it to ground, in that particular locality.”
Victorian Health Department deputy secretary Kate Matson also expressed concern about the cluster, saying two of the new cases linked to the shopping centre were not workers or close contacts and authorities had not yet determined exactly how they were infected.
“Those two cases were [found] fairly late last night so interviews will continue with those two cases today,” she said.
“What we don’t know yet is whether it was a fleeting transmission, perhaps in one of the common areas related to toilets or somewhere else, [or whether it was] passing someone in a local area, or whether they went to one of those identified retail sites.”
One of today’s cases is isolating in Lara, near Geelong, an area no longer in lockdown.
However, Barwon South West Public Health Unit director Eugene Athan said the person was in isolation during their entire infectious period.
Professor Athan said the case has been linked to the Melbourne outbreak and the unit is supporting contact tracers in tracking down anyone who may have been exposed to the virus in the area.
He added that testing has also been ramped up and urged people in the Geelong community to remain vigilant and get tested even with mildest symptoms.
Mr Foley said changes to vaccine availability to allow people aged between 18 and 39 to access AstraZeneca vaccines through the mass vaccination hubs led to a three-fold increase in administered first doses of vaccine compared with Monday last week.
“I think that … is strong emphasis [that] young people, in particular under 39, want to get vaccinated,” Mr Foley said.
“Clearly, young people have assessed their personal situation in a strong and informed manner and many have determined that there are significant risks to remaining unvaccinated during a Delta outbreak.”
There have been 333,000 vaccine appointments already booked for the next month, a third of them for AstraZeneca.
“AstraZeneca has demonstrated itself to be safe, effective, and increasingly available,” Mr Foley said.
Premier Daniel Andrews said on Monday that Melburnians will have to achieve consecutive days with all new coronavirus cases in isolation for their entire infectious period before lockdown is lifted.
Mr Andrews said the most important trigger to lift stage four restrictions would be the number of new cases who had been infectious in the community. Prominent epidemiologists said the public health team will also be focused on exposure sites, high testing rates and wastewater detection.
“We’re still chasing [these outbreaks] very hard,” Mr Andrews said. “We’re not out in front of this yet, I think we’re running alongside it, but we’re not yet in front of this particular outbreak.”
University of Melbourne epidemiologist Tony Blakely welcomed the Victorian government’s decision to lift regional restrictions from 11.59pm on Monday.
Professor Blakely said one of the challenges of locking down regional Victoria, where there have been no cases, was that governments would be “damned if you do, and damned if you don’t”.
He also pinpointed what would be needed for the sixth lockdown to be lifted.
“Victoria needs to get to … two to three days of zero cases of COVID-positive people in the community for any part of their infectious period,” Professor Blakely said.
Mr Andrews is on the same wavelength. “We need to get down to a very low number of cases, if any, that have been out in the community during their infectious period,” he said. “That’s when we’ll have the best chance of opening up and staying open.”
The head of Monash University’s epidemiological modelling unit, James Trauer, said it had become evident in hindsight that the government had not managed Victoria’s exit from the last lockdown correctly.
Associate Professor Trauer said a more gradual release out of this lockdown should include holding off on non-essential retail and possibly the “higher risk” sector of hospitality, “though I know how much hospitality is hurting”.
“It may be that we should hold on for a few more days with our lockdown than may appear necessary to give ourselves that guarantee the virus is eliminated,” he said.
Burnet Institute infectious diseases expert Suman Majumdar said health authorities would be aiming for no new mystery cases, high testing rates and no positive sewage tests in areas where the virus is not known to be.
Victorian health authorities listed three new tier-2 exposure sites on Tuesday: a cafe and post office in Hoppers Crossing and a pastry shop at Williams Landing Shopping Centre.
The Health Department requires anyone who has visited a tier-2 site during the relevant period should isolate until testing negative for COVID-19.
With Melissa Cunningham