Epidemiologist Michael Baker says Auckland's chance of shifting down alert levels this week is "very low" after two new cases were discovered outside of the city on the weekend.
The mystery cases of COVID-19 were detected in Waikato on Sunday - one in Raglan and one in Hamilton East. The cases plunged parts of Waikato, including Raglan and Hamilton city, back into alert level 3 for at least five days.
Speaking to The AM Show on Monday Baker said while elimination of the virus is possible, it would take a toll on people and the Government instead should change the alert levels and wait for higher vaccine rates.
"I think the system does need to be fine-tuned, I mean it did its job last year. But the virus has changed. We've got vaccination so it is a different environment now and I think the alert level system does need some fine-tuning."
Baker said increasing vaccination rates in groups with lower coverage is key to moving out of alert level 3.
He said it's looking increasingly likely Aoteroa won't get to zero COVID cases, which is why the vaccine is so important.
"Elimination is technically possible now but it would require a huge effort and it would be very tough on people.
"So I think now we are in that position of adjusting our measures to buy time while we get that higher vaccine coverage because we know...vaccination is the way out of this pandemic."
Baker said the two new cases in the Waikato are cause for concern given the nature of the Delta variant.
"There are obviously many chains of transmission we need to get on top of but I think alert level 3 with good contact tracing could be enough to stamp out cases in the Waikato, it depends of course how extensive that chain of transmission is."
He said the cases were a good reminder to Kiwis to not get complacent in level 2.
"I think everyone in New Zealand should expect that there is a risk that the virus has seeded into their communities and that's why the rest of the country is at alert level 2, why people should be wearing masks in indoor environments, scanning in and the big one, of course, is getting vaccinated."
Baker said it's crucial officials find out how the cases in the Waikato were infected.
"We need to look very hard at the border around Auckland and I think also the border between the North Island and the South Island."