Level 4 lockdown needs to be done once and done right to stamp out Covid-19, expert urges

A virus modelling expert who is working to inform the Government on its next moves in fighting Covid-19 says the Level 4 lockdown should be done once and done right.

The director of University of Auckland's Centre of Excellence in Complex Systems and Data Analytics, Professor Shaun Hendy, told TVNZ1's Breakfast he believes we need to stay at Level 4 until there are just a handful of cases for our best chance at eliminating the coronavirus.

Modelling from Te Punaha Matatini, the Centre of Reasearch Excellence at the University of Auckland shows how Covid-19 cases in New Zealand could have grown exponentially if the lockdown wasn't enforced.

"What we've seen from the current data is that Level 4 has been pretty effective, you know, we're bringing those numbers down, people will be watching those numbers come down," he said, adding that Easter testing numbers may have skewed results a bit though.

"But still, despite the deaths which are incredibly sad, actually the number of new cases is coming down and that shows that Level 4 has been pretty effective. We're not sure how effective Level 3 will be."

Prof Hendy said if at the end of lockdown the number of cases in New Zealand aren't down to just a handful, the outbreak could "kick off again".

"I think the risk is, if we come out too early then we're going to be faced with another Level 4 lockdown in a few months.

"What we've got to do is we've got to hang in there for long enough to really bring those numbers down to almost nothing and then we'll stand a chance of actually having eliminated the virus in New Zealand."

He said more certainty now would be preferable to having uncertainty later on when it comes to the impact on the country.

The lockdown began on March 25 - meaning we are in week three of four currently.

Prime Minister Jacinda Ardern said a decision on whether New Zealand extends the lockdown or moves out of Level 4 will be made on Monday.

"We're going to be watching things this week, so we're going to be re-running our models virtually every day this week to help inform that decision that'll come next week," Professor Hendy said.

"We would probably say that at the moment, at least parts of the country need to stay in lockdown for longer.

"We've been looking at the country by district and of course some parts of the country haven't had a case for quite a long time, and given that we haven't been travelling much around the country there's a good chance that some of those places don't have the virus present anymore, so parts of the country, we think, could probably come out of lockdown earlier than say the bigger centres or other areas in the country where we're had a large number of cases."

Prof Hendy said that since there wasn't enough time to measure the impact of Level 3 when New Zealand moved from Level 2 to 4 with only 48 hours in between, it was difficult to measure its effectiveness.

"It's difficult to know exactly how the virus will respond, how people will respond to Level 3. I mean, if we all come out into Level 3 and we all go out and party on the beach then that's not going to be good for elimination.

"We do have to keep physical distancing in place and so that's the big unknown."

But when it comes to Level 4, Prof Hendy actually said New Zealanders had responded better than expected and beaten modelling in a good way.

New cases have been slowly tracking off for days.

Yesterday, there were 19 new coronavirus cases announced in New Zealand, bringing the total to 1349. Five people have died from Covid-19 in New Zealand.