'Let's not get overconfident': Celebrate COVID-19 success, but remain on edge - expert

One of the experts whose predictions tens of thousands of Kiwis could die in an uncontrolled outbreak of COVID-19 helped the Government make the decision to move quickly to a full lockdown has defended his work.

Shaun Hendy of Te Pūnaha Matatini and the University of Auckland told Newshub Nation on Saturday the initial modelling was based on what health officials knew about the mysterious virus at the time.

"That was kind of the worst-case scenario. And that's still, you know, the worst-case scenario is still like that. I mean, we've kept it out for now. And if we relax too much, you know, if we switch off the controls, then that's still on the cards for us...

"The international clinical data is a little bit better now, and it's brought those numbers down slightly. What we do know now - we were using the data that was available at the time and we've got better data now. And one of the things we do know is that the impacts on Māori and Pacific populations would be worse. 

"So we'd slightly bring down those estimates, but then the impact on particular communities in New Zealand would actually revise the map."

Since March, it's been discovered the virus is likely much more widespread than previously believed - meaning it probably has a lower mortality rate than the 3.4 percent the World Health Organization once estimated. But the best evidence now suggests it's still far more deadly than the typical flu, can manifest itself in different ways and the long-term health effects remain unknown. 

New modelling released on Friday by Prof Hendy and others suggested lifting restrictions on gathering sizes under level 1 - which could come as early as next week - would nearly triple the chance of a "very large outbreak" from 3 to 8 percent, even though there's only one known case still in the country.

Many of New Zealand's early cases came in clusters from large gatherings, such as a wedding and a St Patrick's Day party. 

With the virus' spread gaining momentum overseas, more cases are likely to pop up from time to time at the border - and as the disease can spread asymptomatically, there's also a chance it could sneak through quarantine. 

"You might come in COVID-free and there's someone at the hotel who hasn't tested positive but may be asymptomatic. And so you could catch that and come out of quarantine and be infectious. So that's still a risk."

Shaun Hendy.
Shaun Hendy. Photo credit: Supplied

Saturday marked the 15th day in a row no new cases were reported in New Zealand. Prof Hendy said if New Zealand's final patient recovers and there are still no new cases, it would be a cause for socially-distanced celebration.

"We should celebrate. I mean, it's a fantastic achievement. There's very few other countries in the world that have got the type of choices that we have, and that's fantastic, so it will be a cause for celebration. 

"But let's not get overconfident, right? The risk is ongoing and it's something we're going to have to manage over the next couple of years."