Professor Michael Plank says the NZ-Melbourne travel bubble should remain closed for as long as it takes.
Closing New Zealand's travel bubble with Victoria was the "right thing to do", an expert says, who adds that it should remain shut for as long as needed.
Victorian authorities have been in talks about Imposing lockdown measures with an announcement due late this morning after confirmation yesterday Melbourne now had 15 cases of Covid-19 and more than 70 exposure sites.
While all the cases were linked, authorities were "very concerned" by the growing number of cases and exposure sites given the type of venues involved which include nightclubs, bars and the MCG.
Yesterday, Covid-19 Response Minister Chris Hipkins announced a pause on New Zealand's travel bubble with Victoria effective from 7.59pm [NZ time].
The pause is effective for 72 hours initially but would be under constant review.
"While the [new Melbourne community] case announced [yesterday] is not unexpected as a contact of a case announced [Tuesday], New Zealand officials have assessed that the most cautious option is to pause the travel bubble with Victoria as there are still several unknowns with the outbreak."
Hipkins said the Government understood the disruption this would cause affected passengers but it was still the right move given the state of unknown in Melbourne at the moment.
Professor Michael Plank told the Herald today the Government's pause on the Victorian bubble was "the right thing to do".
"It buys us some time to see what happens over the next couple of days in terms of the testing and the number of cases that they find.
"The big concern with these outbreaks where there's a missing link is that there might be a whole lot of cases that they haven't found yet.
"Obviously the number of cases itself has grown quite quickly and there's a lot of exposure sites around Melbourne and into rural Victoria and clearly some quite big crowded venues, and so there's the risk of super spreader events, so it was definitely the right call to hit pause."
Plank said Kiwis taking up the travel bubble opportunity to Australia were warned of the risks by the Government, and he hoped people affected had contingencies in place.
"This is what the Government has always been clear about, is that this can happen and that people need to have contingency arrangements.
"Hopefully they will be able to get it contained, if not within the next couple of days, but in the next week or so, so we really just have to wait and see."
The ever-expanding exposure sites had seen not only New Zealand put its bubble on hold but other Australian states.
"With more than 70 exposure sites now, that's obviously quite a lot. Other states are imposing travel restrictions on Victoria and travelling from Victoria so it's not just New Zealand but other Australian states.
"Certainly people who have been to those exposure sites, are typically not allowed to travel to some other states."
Plank said it would be wise for New Zealand to keep the travel bubble closed until the outbreak had been contained.
As for imposing a lockdown, epidemiologist Professor Michael Baker said the Victorian government was likely still in an information-gathering stage and he wouldn't be surprised if they held off announcing a lockdown - if any - until tomorrow.
He said people shouldn't be alarmed at the growing rate of exposure sites and in fact it was a good thing as it showed people were getting tested and their movements recorded.
"In a way, it's a bit like the net is cast really broadly to encourage people to come forward and get tested.
"At this stage, you want to see a huge amount of testing and you don't necessarily expect everyone from those sites of interest would come forward, but it's just to give you an idea of what's happening.
"If you start to pick up extra cases in those places then you start to get quite concerned."
He said on average only one in five adults actually spread the virus, while others did not. However, it was a case of where the 20 per cent had been as they were highly contagious at the time.
He agreed a pause on the travel bubble was a no-brainer, and the unfortunate impact on Kiwis, however if worst came to worst, anyone who had to return home could likely find room in a MIQ facility to carry out two weeks' quarantine.