The 90% Project is an NZ Herald initiative that aims to reach all New Zealanders to get the word out about vaccination so we can save lives and restore freedoms. Video / NZ Herald
New Zealand has a shot at limiting Covid-19's death toll to that of a typical influenza year in 2022, Professor Michael Baker says – but that hinged on plugging four key "immunity gaps".
The Otago University epidemiologist told the Herald he was feeling more optimistic about our ability to prevent large numbers of Covid-19 deaths in our communities than he once was – something he put down to an effective vaccine, high coverage and improved treatment.
As we head into another pandemic year with the new traffic light system in place, he said New Zealand now needed to focus on four priorities: further lifting the national vaccination rate; bringing up coverage among Māori; delivering booster shots; and getting the childrens' rollout underway.
At the pandemic's outset, he and other experts warned Covid-19 could kill at least 10,000 Kiwis if it was allowed to wash through communities unabated.
New Zealand's strong elimination response had since delivered one of the lowest per-capita Covid-19 death rates in the world – and with strong vaccination coverage, Baker said New Zealand was well placed to see that trend continue.
"Hopefully, we're going to end up as one of the very worst countries to analyse mortality trends in," he said.
"Because we remain committed to keeping levels of virus exposure low, and because we're headed toward being highly vaccinated – we're not there yet – I think the scenario that will play out in New Zealand will be very different from what's been happening overseas."
As at yesterday, there had been 43 Covid-19 deaths in New Zealand since the start of the pandemic – or 0.38 per cent of the more than 11,000 cases reported to date.
More than half of those occurred among people aged over 70, with the others aged in their 60s (five patients), 50s (seven patients) and 40s (four patients).
While the Ministry of Health data showed a roughly even split between sexes, Māori accounted for a disproportionate number of all deaths (33 per cent) as did Pacific people (22 per cent).
Last week, director-general of health Dr Ashley Bloomfield disclosed that most of those deaths recorded since the start of Auckland's Delta outbreak were unvaccinated.
But Bloomfield pointed out that, as vaccination rates climbed, so too would the proportion of cases, hospitalisations and deaths among people who were fully vaccinated.
"This is just by virtue of the fact that our vaccination rates are so high, and even though the vaccine is more than 90 per cent — in fact, more than 95 per cent protective against death from Covid-19, it does mean that we will still see that some fully vaccinated people, sadly, will die."
In this context, Covid-19 modeller Professor Michael Plank emphasised the importance of age as a risk variable.
"A fully vaccinated 90-year-old is probably still at higher risk than an unvaccinated 20-year-old," he said.
"And because we have really high coverage in those old age groups, it skews this effect even further and means that we will get a significant proportion of deaths in vaccinated people."
Still, vaccination status was key.
Modelling has indicated that, if 10,000 given people were exposed to the virus and 50 per cent of them were unvaccinated, there'd be 2875 cases and 263 hospitalisations, of which just 13 patients would be vaccinated.
If that coverage level was 90 per cent, however, those 10,000 exposures would result in 1175 cases and just 73 hospitalisations.
Around 92 per cent of eligible Kiwis have now received their first dose, while 85 per cent were fully vaccinated.
Baker said there needed to be a concerted effort to push that rate as high as possible over the next few months – and also to ensure those jabbed early in the roll-out received boosters that will be available from next week.
"Among people who can get vaccinated, we should be aiming for close to 100 per cent."
Critically, he said coverage among eligible Māori – today sitting at 81 per cent for first dose but just 67 per cent for second – urgently needed to come up.
That was a particular issue in rural New Zealand, where models show there are large areas – many with low access to vaccination and health clinics - where Māori vaccination coverage lagged well behind the national average.
"I think this is our single biggest problem with vaccination at the moment," Baker said.
"The way things are going, if the virus does start widely transmitting in New Zealand, particularly as we go into the middle of next year, it's going to be so highly concentrated in Māori populations – particularly those with low vaccination coverage."
Heke Kopa was among those who turned up at a Covid vaccination drive at Northland's Otangarei Rugby Club earlier this month. Photo / Michael Cunningham
The other "immunity gap" he singled out – 5-to-11-year olds – could begin to be addressed when New Zealand approved the paediatric vaccine, which was expected to happen by April.
"I'm surprised that we've taking so long to approve vaccination of children down to 5 years of age, considering that the US and the European Union has just agreed to it," he said.
"I'm hoping we can roll out this vaccine for children as soon as possible."
Looking ahead to 2022, Baker said vaccination status, age, and underlying chronic illnesses would remain three key factors in deaths.
Still, he expected New Zealand's case fatality risk to stay low compared with other countries such as the US (currently 1.6 per cent) and the UK (1.4 per cent).
"That's because the fundamentals have changed," he said.
"Not only have we succeeded in getting reasonably high vaccine coverage, we have antivirals appearing – which means you patients can have much better outcomes if they do need to go to hospital.
"I also think that we're now very unlikely to see our hospitals overwhelmed – something that we were very worried about in March and April last year."
Baker thought it could be even possible to limit Covid-19's mortality rates to that of influenza, which has been responsible for around 500 deaths each year, or two per cent of all deaths.
"If we can manage very high vaccine coverage and we have our boosters, we may be able to keep Covid-19 to a similar range in the coming year," he said.
"But I'd add that there's still much we have to learn about infection itself. We don't know the impact of infection on highly vaccinated populations – and particularly, we don't know how common long-Covid is for young children.
"In many ways, I'm just as worried about chronic effects as I am about mortality."
Baker also wanted to emphasise that his fairly optimistic outlook hinged on New Zealand continuing what he described as a "tight suppression" strategy for Covid-19.
"We cannot place all our reliance on vaccines alone," he said.
"We still need the full range of public health and social measures, including contact tracing, border management and mask use as well as strengthening our healthcare system at all levels."
"Future scenarios also depend on the SARS-CoV-2 virus not mutating into a variant that is significantly more lethal and hard to control, which is unlikely but not impossible."
It remained to be seen whether Omicron – a new variant potentially more contagious than Delta – would deal such a setback.
Plank said that, alongside vaccination, keeping case numbers under control would be a major factor in preventing deaths.
"How well we are succeeding at keeping case numbers under control will determine how many people are needing hospital treatment, and how many people end up dying."
Even with Auckland's case numbers seemingly coming down, he expected New Zealand hadn't seen its last – or biggest – peak in cases.
"As we go into next year and schools go back, that will be a crunch time when possibly cases will possibly start to rise quite sharply again."
