How to control a pandemic WITHOUT A LOCKDOWN
From children staying away from school to babies suffering delayed development, the long-term consequences of pandemic controls are only now being revealed. Nikki Macdonald asks what we should do to contain contagion without a lockdown.
When the government announced a nationwide lockdown in March 2020, one doctor was not ecstatic.
As an infectious disease specialist, Ayesha Verrall was used to putting contagious people into isolation. She knew then what the rest of the world is still coming to understand – the long-lasting and heavy toll of lockdowns, especially on the most vulnerable.
She wished we could instead have managed outbreaks with testing, case isolation and rapid contact tracing. But we had a fire extinguisher when we needed a fire engine, Verrall – now associate health minister – said.
Taiwan, however, had a whole fire brigade at the ready, eliminating the virus while workers still went to the office and children went to school.
So how can we control a future pandemic without a lockdown?
December 31, 2019
Taiwan officials begin boarding flights from Wuhan, China, to check passengers for fever and pneumonia symptoms. Determined to learn from the 2003 Sars outbreak, Taiwan set up a Central Epidemic Command Centre the following year.
So when the World Health Organisation was notified of curious pneumonia cases in Wuhan, Taiwan kicked into immediate action. Six weeks before the disease even had a name, officials began screening flights and setting up border controls, digitally recording passengers’ 14-day travel history.
High-risk travellers quarantining at home were electronically monitored via mobile phones, with NZ$8000 fines for rule-breakers. This was all in place by mid-February 2020 – before New Zealand reported its first Covid-19 case. It was 18 months before New Zealand trialled electronically monitored home isolation.
One of the first things commentators say New Zealand needs to stamp out a future pandemic without confining citizens to their couches is a permanent group of experts equipped to make speedy decisions.
Think Civil Defence, says Auckland University professor of public health Chris Bullen, who also co-chairs the Lancet Covid-19 Commission’s public health taskforce. You need layers of people and tools on standby that can quickly fire up in an emergency.
Philip Hill, Otago University
McAuley Professor of International Health, recommends a pandemic response unit. And better global disease surveillance, to identify pandemic threats quickly. The more warning, the more time to prepare.
Whether New Zealand could have stamped out Covid-19 without a lockdown in those early months of 2020 is debatable, Hill says.
‘‘The issue is that we should have been [able to], if we were as ready as the government said we were.’’
As he wrote in a recent column: ‘‘Pandemic preparedness, at least for a virus with similar properties to Sars-CoV-2, should be regarded as a failure if a country requires a lockdown in the first six to 12 months.’’
January-April 2020 Taiwan’s government takes control of mask manufacturing and distribution, increasing production 8-fold.
Remember the implausiblesounding infection-by-rubbish-bin theory of one New Zealand case?
As Otago University epidemiologist Professor Michael Baker puts it: ‘‘We were absolutely obsessed with surface transmission.’’
One huge challenge of controlling a new pandemic is understanding what you’re dealing with.
You need to know how lethal it is, how infectious it is, how long it takes to reveal itself and how controllable it is. But you also want to know how it spreads.
Because experts thought the virus causing Covid-19 – Sars-CoV2 – spread by contact or surfaces, mask-wearing wasn’t encouraged.
In Taiwan, however, they did it anyway. Way back in January 2020, the government allocated masks to retailers and set a price limit of NZ$16 for 50.
It requisitioned 73 factories, redeployed soldiers to assembly lines, assigned postal workers to mask distribution and set up a public rationing system, based on a person’s National Health Insurance number.
By April, mask production spiked from 1.88 million a day to 16m.
New Zealand, meanwhile, struggled to find enough just to protect health workers.
By September, Taiwan had about a third of New Zealand’s cases and deaths, for almost five times the population.
Baker says that, for a respiratory virus, masking could be key to avoiding future lockdowns. He doesn’t believe we could initially have stamped out Covid-19 without a lockdown. Not because it wasn’t theoretically possible, but because we weren’t ready.
‘‘If everyone was wearing highquality masks in all indoor situations, that also stops the virus. We just didn’t have enough tools initially – we didn’t have the mask use; we didn’t have the test and trace up to scratch at that point. It’s definitely something you’d want to avoid in the future.
‘‘Taiwan were phenomenally ready . . . You need all these systems ready to go, with all the tools you need.’’
February 16, 2020 Taiwan expands proactive community-based testing
Border controls are the first defence against dangerous bugs getting into the community and running rampant. But as we know from experience, they leak.
So to stop outbreaks, you need to quickly find any cases that get through.
In February 2020, as well as testing contacts of travellers with fever or respiratory symptoms, Taiwan began testing clusters of cases with suspicious symptoms, and people with treatmentresistant pneumonia. Earlier flulike cases that had tested negative for flu were retested for Covid-19.
For lab staff globally, one of the biggest early challenges was understanding the threat. How do you test for it? How long does it linger in body fluids? And then you have to ramp up from testing 100 specimens a day to potentially thousands, says Anja Werno, Canterbury Health Laboratories chief of pathology.
‘‘You’ve got to have the staff, supplies, equipment and a place to actually set that up. I think we did that in a reasonable timeframe . . . It can’t be done overnight.’’
She doesn’t believe New Zealand could have negotiated those early months lockdown-free, without higher casualties and a more broken health system.
In a future pandemic, capacity could increase more quickly, as labs now have machines that can switch to high volume within 1 to 2 weeks. But it would still take longer to find 24-hour staff cover and enough consumables, such as reagents and test kits, Werno says.
As a tiny and far-flung nation, New Zealand is vulnerable to supply chain holdups, as closer and more influential countries monopolise stretched supplies. For context, New Zealand tried to order a few hundred ventilators,
while the European Union wanted 10,000.
‘‘So do we need some domestic manufacturing capacity? My personal opinion – absolutely,’’ Werno says. ‘‘I would think it’s actually a very, very important focus area for the future.’’
We also need to better understand testing limitations.
After the August 2021 Delta outbreak, the Government planned for a peak capacity of 60,000 daily tests. But that was an illusion, as it was based on the pooling of tests.
Basically, labs process a bunch of samples together, and only retest individually if the collective sample is positive.
That’s efficient when there are few cases, so few samples are positive. But when more than 5% of samples are positive, pooling stops working, slashing testing capacity.
Testing only helps contain outbreaks if results come back quickly enough to allow contact tracers to notify the contacts of positive cases before they can spread the virus.
New Zealand’s PCR testing system broke when Omicron hit. As the proportion of positive samples soared, testing speed dived. By March 1, 2022, 32,000 samples were older than five days.
The review into that failure said New Zealand must decide how much testing capability it should keep for pandemic management, ‘‘to secure the capacity that has been built and avoid losing accumulated knowledge’’.
That, says Werno, is the milliondollar question. While pandemics will always be challenging, a stretched health system makes them more difficult to get through ‘‘without major calamity’’.
‘‘Our baseline position is not very good. So we need to take that into consideration when we plan for the next pandemic . . . To assume it will be fine, and it will all work out, would be a mistake.’’
‘‘Pandemic preparedness, at least for a virus with similar properties to Sars-CoV-2, should be regarded as a failure if a country requires a lockdown in the first six to 12 months.’’
In 2017, Taiwan’s Centres for Disease Control set up a national contact tracing system called TRACE. It designed a Covidspecific module in January 2020, and close contacts isolating at home were electronically monitored.
One critical tool to contain contagion is contact tracing. If you can identify people who’ve been exposed before they breathe a trail of sickness, you can fence in the virus before it spreads.
But that relies on speed. You need a testing system that quickly identifies cases, and a tracing system that finds contacts before they become infectious.
Verrall’s April 2020 review of New Zealand’s early response found we needed to be able to trace 1000 cases a day, but the system was overloaded by fewer than 100. By October the surge capacity (including casual contacts) was still only 150 cases.
Even in Taiwan, contact tracing was stretched in the early days. One research paper found it had fewer contact tracers than New Zealand. But the country had one thing we initially did not – a national tracing system.
Here, contact tracing was managed regionally by public health teams, using Excel spreadsheets or DHB-specific databases. That made it harder to pull in help.
Over time, that changed. A national IT system means public health specialists from other regions and contracted telehealth call centre workers can now help with outbreaks. A National Investigation Centre now oversees contact tracing for all infectious diseases.
The system’s biggest challenge is Covid-19’s unpredictability, says
the centre group manager, Chrystal O’Connor. That’s likely to be an issue for any infectious disease that can mutate.
Whether you can contact-trace your way out of an outbreak to avoid a lockdown depends both on how good your contact tracing is and how the infection behaves. The shorter the gap between exposure and becoming infectious, the harder it is to rein in.
Taiwan tested and traced out of the original Covid-19 wave, but a May 2021 Alpha variant outbreak took nine weeks to control, and required closing schools.
And Omicron was so infectious, with a shorter incubation period, that Taiwan couldn’t get ahead of it, so had to accept elimination was no longer realistic. But it bought time to vaccinate.
New Zealand was the same. During the August 2021 Delta outbreak, 1700 contact tracers were calling cases and contacts.
Another 804 were added for Omicron. But the numbers were
just too high. During the outbreak’s peak, the tracing service managed more than 20,000 calls a day to support contacts of more than 1000 cases.
But on the busiest day – March 1 – 6075 cases needed investigation. Calling every case was abandoned – the maths just didn’t work.
‘‘A limiting factor to our response is the speed of the virus and how quickly it is passed on,’’ O’Connor says.
So had the original pandemic strain of Covid-19 looked more like Omicron, its advance could not have been halted by traditional contact tracing.
But what about digital contact tracing? Remember QR codes at shop doors, Covid diaries and phones talking to each other via Bluetooth?
The Covid Tracer app had two elements – identifying exposure sites, which triggered alerts to anyone who’d been in the same place at the same time. And the Bluetooth function, which was supposed to alert phones that had been near the infected person.
So how useful was the app? We don’t really know, says Otago University senior research fellow Tim Chambers, who is researching its use.
‘‘What we’re trying to find out here is, if we can get the public health experts or contact tracers to use it, would it be enough to prevent a lockdown? That’s hard to know.’’
Because the app data is held on individual phones, not in a central database, you can’t track whether notifications actually helped contain infectious cases.
The potential benefit of digital contact tracing is scale and speed. While in 2020, contact tracers were sceptical that it would work, within 18 months it became the main tracing tool, Chambers says. Between February 25, 2021, and last Tuesday there were 595,751 Bluetooth tracing alerts and 139,816 location alerts.
Centre for Informed Futures research fellow Andrew Chen, who is researching with Chambers, says digital contact tracing is not a magic bullet.
International estimates suggest you’d need 80% participation to rely on it. New Zealand peaked at about 60%, Chen says.
It also emerged during the Auckland 2021 Delta outbreak that contact tracers weren’t even using the Bluetooth data.
‘‘If it’s not going to be used, then it won’t be useful.’’
O’Connor says while the Covid app diary and Bluetooth data were ‘‘incredibly useful’’ to quickly identify locations of interest and notify potential contacts, ‘‘contact tracing is much more than this’’.
Digital alerts are no substitute for a personal phone call giving guidance and hooking vulnerable people up with social services. O’Connor says pandemic preparedness means having a trained and scalable workforce ready to respond.
Chen says manual contact tracing probably still works better when there are fewer cases. And contact tracing only works at all if the contacts you find then stay home to prevent further spread.
‘‘In terms of how to avoid a lockdown, it’s a question of how much confidence the decision- and policy-makers have that the people who need to isolate will isolate.’’
For Covid-19, tracing 50% of contacts and having 100% of them isolate is more effective than tracing 100% of contacts but with only 50% isolating effectively, modelling shows.
That was driven home in the Delta outbreak, where disease struck vulnerable communities who had more pressing worries, like finding food and a bed.
It’s also a key point for improvement raised by Auckland GP Rawiri McKree Jansen, a Māori Pandemic Group co-leader. While whānau want to help the pandemic response, they need sick leave, wage compensation, food and cash support.
‘‘I think all of those could have been organised much quicker, and more comprehensively.’’
Bullen says targeting high-risk populations should be a priority in any future pandemic, as they can become infection epicentres.
Plus, working with Māori and Pacific community providers – a lesson learned during the Meningococcal B vaccine programme, but somehow forgotten.
‘‘The reflex should be, how can we do, right now, what’s needed for low income, marginalised populations whose access to information, services and support is very different . . . They should be targeted and prioritised. It’s a moral principle. But it’s also a practically important one.’’
Making sense of the numbers
How did maths and physics boffins become the faces of New Zealand’s pandemic response? If you’re going to rely on test and trace instead of a lockdown, you’d better be sure you’ve got good data.
It was a modelling paper that forecast Britain’s mitigation strategy would end in disaster, and forced a policy U-turn.
New Zealand’s modelling effort started out as ‘‘sticking together researchers with bits of Sellotape’’, says Covid-19 Modelling Aotearoa programme co-lead Dion O’Neale.
‘‘Early on, when we had less time, we had crappier models. Because you had to build them as quickly as possible, and they gave less information.’’
Initial modelling is always going to be best-guess, as you’re still learning about the virus – how infectious it is, how long it takes to incubate, how lethal it is.
But even if you have great data, modelling is not foolproof. People aren’t as predictable as nice uniform numbers on a page, O’Neale says.
’’What we learnt in the August outbreak last year is, you can model that on average, but if you’re wrong in one particular community, and that community doesn’t look like your average population, then you’re just going to have spread through that community.’’
He also emphasises the need for better social support so vulnerable people can isolate at home.
One thing still missing from New Zealand’s response that would help modellers is surveys to estimate what percentage of the population has been infected, O’Neale says.
If you have 200 reported cases and 200 cases in hospital, you need to know whether the disease is incredibly severe, or whether there are simply thousands of undetected cases.
As with most aspects of New
Zealand’s response, modelling has massively improved over time. O’Neale hopes those skills will be retained.
‘‘I would advocate trying to turn Covid Modelling Aotearoa into something more like Contagion Modelling Aotearoa.’’
In preparation for a disease onslaught, Taiwan set up 20,000 isolation rooms with 14,000 ventilators.
It’s an average day well beyond the normal winter overload and New Zealand’s health system is still struggling to cope.
There’s no way we could have got through the initial Covid surge without a lockdown, says intensive care specialist Andrew Stapleton.
New Zealand is not China, which built a 1000-bed hospital in 10 days. Or Taiwan, which set up 20,000 isolation rooms with 14,000 ventilators virtually overnight. Nationwide, we currently have around 280 critical care beds – 15 more than in July.
While hospitals could now quickly reinstate measures that initially took months to set up, any future pandemic response would still be constrained by ageing infrastructure and staff shortages, Stapleton says. ‘‘The extent to which we were saved by lockdown cannot really be overstated.’’
Lockdowns must remain in the pandemic tool kit. But they should not be used to compensate for lack of planning, says Bullen. And if needed, they should be short and geographically limited.
‘‘If we don’t have a vaccine readily available, and we don’t have enough information about its specific characteristics, and it looks like it’s very virulent, with a high case fatality, I think sometimes lockdowns should be considered. But I think they are an option of last resort.
‘‘I don’t think the Government or the public wants to go through all that again unless we absolutely have to.’’
Hill says even if it runs to hundreds of millions, the cost of being prepared is justified to avoid lockdowns.
‘‘The social cost of a lockdown should also not be underestimated. There should be no spin about us being prepared when we are not. We can be good enough if we want to.’’