Victoria’s case numbers should fall below 200 in the coming week, but Melbourne should prepare to be in some stage of lockdown until a vaccine arrives, Australia’s top infectious disease experts have said.

After Victoria recorded its lowest numbers in a month, chief health officer Brett Sutton said they should fall even further this week.

“It’s still a pretty big number: 7274 active cases still in Victoria, but I do expect that to decrease by a couple of hundred every day this week, and more next week,” Professor Sutton said.

“I would hope that we’re in the hundreds, not in the 200s, next week.

“But again it all depends on everyone doing the right thing, which includes stepping up for testing.”

Melbourne is yet to see the full effect of its strict lockdown measures but should do so in the coming week, epidemiology chair at Deakin University Professor Catherine Bennett said.

“We saw the numbers pushed down after masks we brought in, but we’re now coming down into two weeks of community lockdown, so we would expect to see an impact,” she said.

Melbourne should start to see the numbers of cases affected by lockdown this week. Photo: AAP

“This week we’re expecting numbers in the hundreds. We are still hearing about new outbreaks and they will keep seeping into our numbers.

“But the number of outbreaks is also slowing down, which makes them easier to trace.”

She said lockdown was our only chance to get rid of local transmission. However, elimination is not just unlikely but unhelpful to think about.

“The elimination or suppression argument is a false dichotomy. Suppression is the act, elimination is the endpoint that you would love.

“I think our challenges are we had so much virus through the community so quickly. We don’t know how we’re going to respond to Stage 4.

ANU Medical School professor of infectious diseases Peter Collignon said we won’t see the case numbers return to just double-digit growth for weeks.

“You may start seeing less than 100 cases within a week,” Professor Collignon said.

“Then I hope it would get to 10 or 20 a day, but it’s not going to be fast. It’s a gradual fall, I don’t think you’ll get down to one or two cases a day for a couple of months.

The city may have to get used to some lockdown measures for some time.

“I would think by October we should see a low number of transmission.”

The fact that COVID-19 had been so widespread in Melbourne meant it won’t disappear until a vaccine exists, he said.

“I don’t think it’ll disappear because it’s been so relatively widespread in Melbourne,” he said.

“I worry about using the term elimination, not that I think it may not happen – you can argue it has happened in Perth, Brisbane, Canberra.

“The trouble with that though is people think ‘I can go back to my past behaviour’ and for the next two years until we have a vaccine, I don’t think we can do that.”

Depending on how Melbourne acts after the strictest lockdowns are lifted may eliminate it.

But until there is a vaccine, it’s likely everyone will have to practise some form of social distancing, he said.

“We’re going to have to do it for the next couple of years,” he said.

“To get out of this mess, do the basics and do them everywhere. That means keeping physical distance as much as possible – Including in your own home, if someone is sick.

“Wash your hands, keep at least 1.5 metres from people, wear a mask – all those things decrease transmission.”