The Government is putting on a brave face and insisting that Level 3 restrictions in Auckland will hold, but the true hope is that vaccinations will cross the 90 percent threshold before we have to find out the hard way, Marc Daalder reports
Analysis: The Government is now playing a game of chicken in Auckland, hoping desperately that people will get vaccinated quickly and follow the rules in the meantime, lest it be forced to make a tough call on raising restrictions in the supercity.
The 60 new cases reported on Sunday – 56 of which were in Auckland – may have been the first sign that Level 3 measures are not just cracking, but buckling completely. Prime Minister Jacinda Ardern now says the reproduction rate in Auckland is around 1.2 or 1.3 – meaning that 56 cases in the city on Sunday could turn into 73 next week and then 95 the week after. Within a month, the city could be reporting 160 new cases a day, under that metric.
Once case numbers get high enough, the healthcare system is threatened.
First, contact tracing will struggle to identify new cases before they infect others, which means that the disease will spread faster. The Ministry of Health currently has the ability to trace 6000 new contacts a day, which at current contact rates would mean it would struggle with more than 215 cases a day. Some effort has gone into improving the odds over the past few days – not through bolstering tracing capacity but through reinterpreting which contacts need active management and which are “casual” contacts that can be left to their devices unless they develop symptoms.
Director-General of Health Ashley Bloomfield said this was informed by just one out of thousands of tangential contacts testing positive earlier in the outbreak. While under elimination we would have wanted to catch every case, the new suppression strategy means we can now afford to let a few slip by if it means the contact tracing system holds up to be targeted at the contacts most likely to test positive.
After contact tracing collapses, the hospitals are the next target. This has always been the greatest threat from Covid-19. To the average patient, it is a mild or even completely unnoticeable virus. While a large percentage of cases later develop long-term conditions that can be debilitating, the most acute danger is from the relatively small proportion of cases that require hospitalisation. Over the current outbreak, one in every 10 cases has required some time in hospital. A smaller percentage need intensive care.
If cases swell to large enough numbers, however, that small percentage hospitalised or placed in ICU becomes an absolute number that is too high for our under-resourced health system to manage. As of September 6, there were just 327 resourced ICU beds in the country. As those fill up, people needing hospital care for issues not related to Covid-19 might miss out. Moreover, those who do visit the hospital for emergencies could end up infected there, further worsening the outbreak.
The vaccination race
The Government now finds itself staring down the barrel of collapse of Auckland’s hospital system – the same scenario it escaped in March 2020 through locking down and eliminating the virus. Elimination, of course, is no longer on the cards in Auckland.
There is, however, one new tool in the toolbox. That’s vaccination, which drastically reduces the chance of someone being infected with the virus in the first place and reduces the potential for them to be hospitalised with it to infinitesimal odds.
The race is now on for Aucklanders – and New Zealanders more widely – to get both jabs and increase vaccination rates to a level where health system collapse is no longer possible, as long as some baseline public health measures and case management continue.
The problem for the Government is that this achievement is at least five weeks away. Around 85 percent of eligible Aucklanders have had their first dose, but the Government wants to see rates above 90 percent. According to modelling from Te Pūnaha Matatini, uptake needs to be closer to 95 percent if children aged five to 12 are still excluded from the rollout.
Even if those remaining 5 to 10 percent were to be vaccinated today, it would still be three more weeks before their second jab and another two weeks before they were considered fully protected. And, of course, the holdouts won’t all get vaccinated today. Vaccination certificates for most recreational activities and mandates for many employees in the health and education sectors will speed up uptake, as will the increasing risk posed by the virus – epidemiologists are now warning that New Zealanders should prepare to come into contact with Covid-19 personally by Christmas.
But what about the intervening weeks or months? As Ardern said, with some understatement, “New Zealand is at one of its trickiest moments of the Covid pandemic so far”.
The truth is that this is the most dangerous time for New Zealand since Ardern put the country into lockdown in March of last year. This is our do or die moment – for some people, literally.
It remains to be seen whether the upwards trend in case numbers in Auckland continues. As long as the reproduction number remains above 1, cases will continue to rise. But the key figures to watch are the number of unlinked cases reported each day (which represents the potential for undetected chains of transmission, and which is rising) and the number of cases infectious in the community each day (signalling the potential for new people to be infected, and also rising).
Combined, these two warnings signs could push the reproduction number further up, even as vaccination works to reduce the number of infections by around half.
The current reproduction number of 1.2 or 1.3 is sustainable, Te Pūnaha Matatini disease modeller Michael Plank told Newsroom, because the second jabs from people who got their first dose during the late August and early September vaccination sprees will start to come into effect and dampen transmission. And at 1.2 or 1.3, case numbers are rising slowly enough that the health system is unlikely to be threatened before that vaccination effect kicks in.
If the reproduction number rises further, however, then hospitals could be overwhelmed before vaccination rates hit a high enough threshold. At 1.4 or 1.5, Plank said, a “circuit-breaker” lockdown might be needed.
What do those scenarios look like in real terms? Over the past week, we’ve had 173 cases infectious in the community who may have been able to pass the disease on to those outside of their households.
At a reproduction rate of 1.2, that would lead to 360 new cases a week in a month's time and 744 new weekly cases a month after that.
The 1.5 reproduction scenario is far worse, with weekly cases hitting 876 in four weeks' time (meaning more than 100 cases a day, on average) and surpassing 4400 weekly cases (600 a day) four weeks after that.
Compliance the key question
The $1.4-billion-a-fortnight question is whether the Government would implement a circuit-breaker Level 4 lockdown if it were faced with this situation. On Monday, Bloomfield implied he would be willing to recommend whatever the scenario required.
"We would always give advice based on what we're seeing in front of us. We haven't - and we won't - resile from giving what we think is the best public health advice."
But there's another consideration here. Ardern said on Monday that the Government also had to take into account the willingness of Aucklanders to follow heightened restrictions.
"As we look at what is happening in Auckland and we consider, not only the restrictions but one of our criteria has always been compliance and adherence and the ability to continue to comply. Over time, adhering to really strict restrictions is hard and you can expect that human behaviour might change. Last week, what we sought to do was provide additional things people can do safely to try and prevent people perhaps doing things that might be unsafe," she said.
This highlights the intractable problem the Government now faces: The full force of fatigue. And it shows how Ardern has locked herself into a self-reinforcing cycle, in which she must lower restrictions slightly to keep compliance high, but in doing so exposes Aucklanders to more risk, even as cases continue to rise, not wane.
The most worrying interpretation of Ardern's comments is that, if the Government felt it needed to move Auckland back to Level 4 or some higher state of restriction than the current Level 3 in order to avert the collapse of the hospital system, Aucklanders just might not comply.
That fatigue might be shaken if the fear of Covid-19 is strong enough, but that would likely require the system to already be on the very brink of being overwhelmed. At that stage, an escalation in restrictions would be too late to avoid collapse.
Hence, the do or die race to vaccinate. At some stage, as restrictions continue to ease in Auckland in order to keep everyone on board with the rules as written, the virus will be freed enough to spread rapidly. The Government's hope is that, by the time it gets to that point, vaccination rates are high enough to prevent a rise of cases from correlating to a rise in hospitalisations and deaths.
Of course, Ardern won't say this explicitly - that in itself might weaken compliance. This is the game of chicken, with the Government insisting Level 3 will hold up but hoping desperately that it won't have to find out if that's actually true, or if stricter measures are needed.
If vaccination rates don't increase quickly enough, then Ardern will be faced with the toughest choice of the pandemic: Raising restrictions and risk them being ignored or doing what she can to mitigate the collapse of the hospital system.