Sir Ashley Bloomfield says the worst of the Covid-19 pandemic appears to be over - three years on today from New Zealand's first lockdown.

But he says lockdowns "may have a place" still in the future.

More than 2,250,000 people have been infected with the virus here, despite New Zealand stopping most community transmission in 2020 and 2021.

The former director-general of health - who is now a population health professor at the University of Auckland - told RNZ on reflection: "It's clear, we're past the worst of the pandemic, it feels like we're out the other side, and that's the sense I have both in Aotearoa New Zealand, but also internationally."

He says it had been "a pretty bumpy journey" but recent travel overseas had shown him: "Everyone's sort of life's getting almost back to completely normal. So that's a good thing."

Sir Ashley says he is greatly satisfied that three years on from the first lockdown, New Zealand still had negative excess mortality.

This metric predicts the number of expected deaths every year in a country, and compares it to current totals.

"What we found in Aotearoa - in 2020, 2021 - we had less deaths than you would have predicted based on the previous years. And whilst once the Omicron variant came along, yes, we did see Covid-related deaths, the numbers have climbed. Still, if you look over those three years, cumulatively, we're still not back at the level, the number, you would have expected.

"That is unique, virtually unique around the world," he says.

"Lockdowns were an important tool in the overall response and not one we had anticipated using, but one now that we do have experience with and know that if we are in a similar situation in the future, with that same degree of uncertainty, while we understand the virus better - and while a vaccine has been developed - it is a tool that we can deploy," says Sir Ashley.

"It's hard to know what the likelihood of future lockdown is ... lockdowns may have a place.

"It is dependent on the nature of the virus and of course, the speed with which we act."

The former director-general also says he is proud of the collective efforts New Zealanders had made as well as compliance.

"Some people say 'oh Kiwis are just kind of more compliant and more likely to do what the government asks them than other countries'. Well, actually, I don't think so. That's not my experience in everyday life.

"But I think what was effective about our first lockdown, especially, but even subsequently, of course [is], you cannot police a lockdown - it requires the vast majority of people to understand and own and act on the request."

He has had uplifting feedback from overseas health leaders - but does not take credit for how New Zealanders worked collectively upon request.

"Dr Mike Ryan, he's from Ireland originally, he's been involved in health emergency response for many years ... And he said, 'Look, I'm not just saying it because you're here [at the World Health Assembly] Ashley, but we in WHO do think of New Zealand's response as one of the best in the world and really setting an example for other countries."

Sir Ashley has also welcomed the Royal Commission of Inquiry into New Zealand's pandemic response.

"I am also really pleased that we are having a Royal Commission because that gives us a chance to really have a look and see - not a 'Spanish Inquisition' about every single decision - but actually what do we need to do to be even better prepared for the next time."

The Royal Commission of Inquiry is expected to be completed in June 2024.

Sam Olley/RNZ