The person at the center of Auckland's latest COVID-19 case has "absolutely" done the wrong things, says epidemiologist Professor Michael Baker.
Auckland has plunged back into COVID-19 alert level 3 after it was revealed the most recent positive case went to the gym after being tested for the virus.
Prime Minister Jacinda Ardern said on Saturday the person, known as Case M, created "multiple high risk situations" for which the only answer was lockdown.
On Monday, Baker said he hopes the country has the message now.
"Case M has been out in some high risk situations - that's obviously the wrong thing to do. Hopefully everyone in the country has that message clearly now."
Baker told The AM Show around one in five COVID-19 cases transmit the virus extensively.
"That's obviously enough to keep [the virus] going, but sometimes you do get lucky so this person may not have been very infectious - but we just don't know."
It will be at least a week until New Zealand will know what damage has been done by the latest case, he said.
"The best case is we get no new infections in the next week but the incubation period is around five or six days, so we're always looking backwards."
He says New Zealand's vaccination campaign will be massively helpful - and because Aotearoa is better placed than other countries, the Government has options for how it decides to immunise the population.
"We have a different set of priorities than countries where people are dying every single day - we can use a vaccine very strategically to build up our defences so that obviously means border workers and their families but that could be extended to create a ring around that area."
But south Auckland councillor Efeso Collins says vaccination could be harder than the Government anticipates due to strong anti-vaccination sentiment in the region.
He told The AM Show he has received furious messages from constituents after he openly supported vaccination.
"Some people have called for me to be excommunicated, and I can understand it because some people are very strong in their views - some might say militant."
Collins says there's been a communication gap between the Ministry of Health and his community "for a long time".
"I don't know if we have the right people on the ground, delivering the information in languages the community can understand."
He says more investment is needed to ensure all of south Auckland has the information they need.
"Part of the problem is the bureaucracy they need to show investment and trust for the ones out there."