‘If we hadn’t locked down when we did, it would have just taken off’ says epidemiologist

New academic analysis shows the level 4 lockdown in New Zealand not only allowed the country to catch up to Australia, but surpass it in terms of per capita Covid-19 cases.

The daily case rate in New Zealand has been only 59 per cent that of Australia since the start of a 33-day lockdown, according to Otago University Associate Professor Brian Cox, an epidemiologist and specialist in public health.

His analysis shows New Zealand’s rate of confirmed cases per capita was far higher than Australia’s at the start of the lockdown, but drew level after about three and a half weeks and is now well below Australia’s.

Currently, New Zealand has 229 confirmed cases (not including probable) and 3.9 deaths per million people, compared to Australia’s 269 confirmed cases and 3.4 deaths. “If we hadn’t locked down when we did, it would have just taken off and we would have been way above Australia,” Cox told the Herald.

His work comes amid comments that New Zealand could have had more lenient lockdown rules, as Australia has appeared to get similar public health outcomes while allowing hairdressers, retailers, construction and manufacturing to operate.

Infectious diseases physician and microbiologist Professor Peter Collignon told the

Daily Mail Australia that though both countries had seemingly quashed Covid-19, “Australia has achieved it with less collateral damage”.

“We’ve been able to achieve success results without the severe social or economic impacts the lockdown has had in New Zealand.”

Prime Minister Jacinda Ardern has pushed back strongly on any suggestion the lockdown measures in New Zealand were too severe.

“We should not confuse the success of our actions with overreaction, and there is plenty of proof around the

The worst thing that could happen right now is another cluster breaks out. That’s what we must try to avoid.

Brian Cox

world of the devastating result of responding too late.”

Cox’s analysis shows New Zealand’s lockdown was far more successful than Australia’s.

“Our lockdown was more effective and we certainly couldn’t have gone another week before we did that. That would have been a mess, otherwise.”

Cox compared Australia and New Zealand from the first day of each country’s epidemic — or the day each country reached four confirmed cases per New Zealand’s 4.9 million people.

“Four separate cases are considered suggestive of community spread,” Cox said.

Cox tracked the three-day rolling average in the daily confirmed case rate to iron out daily spikes.

The rate of per-capita daily cases rose in New Zealand far more rapidly than in Australia, and New Zealand’s lockdown started 19 days into the epidemic while Australia took four to five weeks to implement different restrictions in different states.

Last week, epidemiologist Sir David Skegg said the slower initial growth rate in Australia was perhaps because its public health units were far better resourced.

The equivalent units in New Zealand had been drastically underfunded by successive governments, he told the Epidemic Response Committee.

Cox said the number of cases took off here because there were so many clusters.

“It’s the same problem Italy had. If you start with clusters early, the cases increase very rapidly and it can quickly become uncontrollable.

“We were able to hold that back, seal it off, and now we’re just closing off the clusters. The worst thing that could happen right now is another cluster breaks out. That’s what we must try to avoid.”

One of New Zealand’s 16 clusters — the one linked to a wedding in Wellington — has been declared closed because there have been no new cases in 28 days, or two two-week incubation cycles.

The success of both countries has opened the prospect of a transtasman Covidfree bubble, where citizens of both countries might be able to travel freely across the border without potentially importing Covid-19.

Cox also looked at Singapore, which has had a second wave of Covid-19 after an outbreak in migrant workers’ dormitories.

“The daily rate in Singapore has increased and is now, at day 91 of their epidemic, very high at 165 per million people.

“This is a warning there is still considerable work necessary to stop the epidemic.”