New Zealand's Covid-19 death toll is expected to more than double in the next six weeks — with as many as 300 fatalities predicted by the time the Omicron outbreak reaches its peak.
That's according to the latest pandemic modelling that also suggests the outlook will not be as dire as was first feared.
While the country's pandemic toll is expected to reach up to 300 deaths by the end of April, when the present wave should have already peaked, modelling from late January — which was done before Omicron had made its way into the community — estimated the wave would result in somewhere between 450 and 800 deaths.
"At the time, we were thinking it would come out more towards the low end: around 500," Covid-19 modeller Professor Michael Plank told the Herald.
The new estimate, he said, took into account the younger age cohort of the people who have so far caught the virus.
"What we're seeing now is something more like 250 to 300 deaths through to the end of April."
This is despite case numbers tracking higher than the high-transmission scenario in the northern region, which includes Auckland and Northland. Models rely on the assumptions they are based on, and if the outbreak spreads among older people more than expected, the number of fatalities could exceed the estimate, Plank said.
"The reason is the shift in age distribution," he said.
"We've seen really high rates in younger groups, but so far lower rates in older groups.
"We're starting to see that shift a little bit. Hopefully it doesn't shift too much."
Yesterday there were 960 people in New Zealand hospitals — nearing the 1000-odd that modellers had estimated for the peak. ICU numbers, 22 yesterday, continue to track lower than expected.
Director general of health Dr Ashley Bloomfield said the average age of those in hospital across the four hospitals in Auckland and Northland was 58, up from 40 on Friday.
This may align with the virus spreading more widely among older people, but not necessarily.
"It could be just that you're discharging younger people, and those who are left are older," Plank said.
The virus spreading among older people is the warning Covid-19 Response Minister Chris Hipkins gave when asked whether New Zealand seemed relatively well positioned to manage the Omicron peak.
"It will make its way into the older population. It probably already has by now," he told the Herald last week.
"In the next few weeks, that will be instructive as to whether we're going to see a higher rate of mortality or hospitalisations amongst that group."
In the pandemic so far, 54 per cent of New Zealand cases have been under 30, while 72 per cent have been under 40. Only 2.2 per cent of all cases have been 70 or older.
Just over a quarter of hospitalised cases have been under 30, but 21 per cent have been 70 or older.
For ICU admissions, a quarter have been under 30 while 9 per cent have been 70 or older.
Plank said the new estimate accounted for some shift back towards older people.
"For younger age groups, the virus starts to run out of people to infect in those groups much earlier than in the older age groups. That in itself does cause a shift in the age distribution over time.
"The model accounts for that, but ... if the shift is bigger than what we're anticipating, that would push up those hospitalisations and deaths."
Another factor that could increase the figures is the ethnicity of cases.
Māori and Pasifika, all other things being equal, are more likely to suffer severe health impacts from catching Covid-19.
Māori make up about 17 per cent of the population, but 20 per cent of all cases, and 25 per cent of all those hospitalised. Pasifika make up 8 per cent of the population, but 21 per cent of all cases and 38 per cent of those hospitalised.
Plank said the model didn't take into account the ethnicity of cases, so if Omicron spread more widely among those communities, it could push the number of fatalities higher than the estimate.
So far, Omicron has mainly spread among Pasifika, but Māori are increasingly featuring among hospital cases — from 80 nationwide last Wednesday to 125 a day later.
The model doesn't include subsequent waves following the peak, which are expected in New Zealand, though at lower levels than the peak.
New Zealand's Covid-19 death toll has more than doubled from 52 in mid-January, when Omicron first leaked into the community, to 117 yesterday.
However, cases in New Zealand have skyrocketed.
Before Omicron landed in New Zealand communities, the number of cases for the whole pandemic — about 15,000 — were 6000 cases fewer than the total reported for yesterday alone.
And these were just the reported cases, which are reliant on people getting a rapid antigen test if symptomatic, and reporting the results of their test to the Health Ministry.
Experts have estimated the number of actual cases may be three to four times higher than the number reported, which could mean up to 80,000 new infections yesterday and up to 800,000 active cases at the moment.
Omicron is also not mild for everyone. For those who are unvaccinated, its virulence is likened to the original strain of the virus.
One of the key factors in keeping the death toll low is having a high booster rate among the elderly and the immuno-compromised.
As of March 6, 78 per cent of Pasifika aged 65 and older had been boosted, which is far more effective against Omicron than two doses.
For Māori, it was 86 per cent, while for non-Pacific, it was 88 per cent. More than 90 per cent of those aged 80 and over have been boosted.
Why?
— Eric Topol (@EricTopol) March 14, 2022
Here is the vaccination coverage by age vs Singapore and New Zealand. Also contributing is the high use of Sinovac, for 2/3rd of elderly who were vaccinated, which has reduced efficacy vs Omicron pic.twitter.com/ncS1Vlgrls
Compare this with Hong Kong, where per-capita deaths were higher than anywhere else throughout the entire pandemic and hospital morgues were reportedly at capacity.
On February 9, when its Omicron wave began, more than 60 per cent of people in Hong Kong aged 80 and older were unvaccinated.
While the vaccination rate among older Kiwis is high, it is still lagging among younger people; there are still about 950,000 Kiwis 18 and older who are eligible for a booster who haven't had it yet.
Bloomfield yesterday continued to urge them to get boosted.
Data over a two-week period for the northern region showed only 16 per cent of hospital admissions for Covid symptoms had received a booster at least two weeks prior.
The rest, 84 per cent, hadn't been boosted.
He added: "A third dose could be life saving."