The number of people rushed to hospital after becoming infected with Covid-19 has soared rapidly compared to last year's nationwide lockdown.
One emergency doctor said the higher number of hospitalisations was because of the speed and agressiveness in which Delta was spreading.
This data comes as lead epidemiologist Professor Michael Baker warned if elimination failed, New Zealanders could be in lockdown until Christmas.
While falling case numbers were providing hope, the Delta variant of Covid-19 could spread quickly, which meant elimination could still fail, Baker said.
The latest Ministry of Health figures showed that on day 19 of lockdown there were 38 people in hospital fighting the highly contagious virus, up from 7 people less than two weeks ago.
In comparison to last year's nationwide lockdown when the first wave of Covid hit, there were just 15 people in hospital on day 19 of the nationwide lockdown, which was less than day seven, when there were 16.
Thirty-nine per cent (15 out of 38) of those hospitalised are currently in intensive care units (ICUs). On day 19 of last year's nationwide lockdown, 40 per cent (6 out of 15) were in ICU.
There were more active cases on day 19 of last year's lockdown (798), compared to this year (721), but this gap was closing.
The reason why numbers were higher last year was likely because there was a longer lag for the Government to shift the country into alert level 4.
By the time the country moved to alert level 4 on March 25 last year, there were already 205 people who had been infected (183 active cases as some had recovered). The first community case was reported on February 28 last year.
In comparison to this year, the Government moved the country into a nationwide lockdown on August 17 after just one person tested positive for the virus in the community.
Australasian College for Emergency Medicine president Dr John Bonning said more people were ending up in hospital because the virus was spreading faster than the first wave, as the Delta variant was more transmittable.
"We went from one person to 800 people in just over two weeks; it is significantly more transmittable.
"Our guess is if one person in the household gets it, the whole household gets it," he said.
This meant it was much more likely that someone in that household could end up in hospital.
"The ones that were getting really sick in New Zealand were believed to be over 50, with comorbidities and were unvaccinated," Bonning said.
But overall more younger people were being affected because that was the age bracket of the earlier Delta cases.
As of Friday, 64 per cent (489) of the total 764 active cases (including those in MIQ) were under the age of 30.
Bonning said perhaps that was why there were fewer people in ICU, compared to last year, because the younger people were fitter and more capable of fighting the virus.
The Herald asked the Ministry of Health for a breakdown of those in hospital and ICU who had been fully vaccinated or received one dose. A spokesman said: "At this stage the ministry is not providing a breakdown for the current hospitalisations."
Last month, the Herald revealed how day-to-day ICU capacity hadn't improved since the pandemic began and often struggled with "business as usual" demands.
There are currently 284 fully staffed ICU beds across public hospitals, and 629 ICU-capable ventilators, with 133 in the national reserve if required.
But while the focus had been on the need to increase ICU capacity, Bonning said emergency departments were even more at threat of running out of room.
"We need more isolation space within hospitals, in our respiratory wards and emergency departments, where most people with Covid end up."
He referred to a UK statistic: 25 per cent of people who caught Covid became infected while in hospital.
'We do not want to end up like that," Bonning said.