Analysis: New Zealand nearly sleepwalked into disaster due to a lack of strategic thinking around Covid-19. How can we front with an even better response for the next pandemic? Marc Daalder reports
Michael Baker broke into tears at around 1:48pm on March 23, 2020.
Jacinda Ardern had just announced New Zealand was now at Level 3 and would move into a full Level 4 lockdown in two days’ time. Days of advocacy by the University of Otago epidemiologist through back channels and the media, urging the Government to take a stronger approach against Covid-19 had paid off.
“It sounds melodramatic to say now or never, but I think it’s the case,” Baker told me on March 21, after Ardern had announced the alert level system.
Now, Baker has contributed to fellow Otago epidemiologist Amanda Kvalsvig’s paper outlining how New Zealand might be able to front up with an even better response to the next pandemic.
Lack of preparedness criticised
Baker was such a strong advocate of lockdown because he knew New Zealand didn’t have the ability to control a skyrocketing caseload without it. We had one of the lowest per capita intensive care capacities in the OECD – less than a third of the OECD average and half that of Italy and Spain, which had already been overwhelmed by the virus.
In fact, Baker had been warning for years prior to the emergence of Covid-19 about our poor pandemic preparedness. This went beyond PPE stocks and ventilators per capita and extended to our lack of an operational public health infrastructure and an inability, he said, to think strategically about health emergencies.
In the early stages of our response for Covid-19, Baker watched in horror as we appeared to sleepwalk towards the same disaster that has befallen most other western nations. The key issue was our lack of proactive and strategic thinking, he says.
Newsroom has previously investigated New Zealand’s poor preparedness, detailing how we ran our response off of an influenza pandemic plan which didn’t realistically entertain the possibility of eliminating community transmission of a pathogen once it had started.
The key was in the incubation period. In influenza, the virus usually becomes contagious around one to three days after infection takes place. This means contact tracing and isolation of cases is virtually impossible, as it would have to occur within a matter of hours at best.
Meanwhile, Covid-19 has a longer incubation period of between three to 14 days – plenty of time to trace and isolate the contacts of someone who has tested positive.
“With this coronavirus, at the level of spread that it got to in New Zealand, if that was pandemic influenza, it would be impossible to control, because the incubation period of pandemic influenza is less and so it will spread rapidly before you can do all the contact tracing,” Kvalsvig and Baker’s colleague Nick Wilson told Newsroom in April.
“With this coronavirus, with a five to six day incubation period, you’ve got more time and so the ideal pandemic plan would have said: ‘Pathogens can vary enormously and for some pathogens, if they have a long incubation period, you should as a country put a lot more investment into things like contact tracing, case isolation and home quarantine’.”
Nonetheless, Wilson said, bureaucratic inertia meant the Government treated the virus like influenza, in which containment or elimination would not be possible and contact tracing a waste of resources. It was only stark modelling from the Imperial College London, reproduced in a New Zealand context by Baker and Wilson and modellers at Te Pūnaha Matatini, which shook the Government out of its complacency in the crucial days leading up to lockdown.
Even having to resort to lockdown could have been avoidable, Baker said, if New Zealand had closed its borders earlier and had a more robust contact tracing and case management capacity. Taiwan, for example, never locked down. How do we achieve that type of response the next time around?
How to respond better
Now, Kvalsvig has come up with something approaching that “ideal pandemic plan”, with contributions from Baker. In a new paper in the Journal of the Royal Society of New Zealand, the epidemiologists write about the lessons to be learned from our Covid-19 response for the next pandemic.
“Public health lessons from one pandemic become the planning assumptions for the next one. Aotearoa New Zealand’s 2017 pandemic plan was derived from past experience of influenza. When Covid-19 emerged as a major global health threat, it took time for the realisation to crystallise that this infection was so different from influenza that it required a completely new pandemic response strategy,” Kvalsvig and Baker wrote.
“The experience with Covid-19 has demonstrated the risk of having a pandemic plan that is too pathogen-specific. Assumptions based on management of one pathogen will not necessarily translate to another, and identifying and rejecting unhelpful assumptions may cost valuable time. Aotearoa NZ’s next pandemic plan needs to adapt flexibly to respond to an unfamiliar pathogen, with a consequently broader set of strategies to consider.”
The epidemiologists propose a new planning framework that is pathogen-agnostic. Rather than an influenza pandemic plan or a coronavirus pandemic plan, this would be able to respond to any kind of pandemic. The plan would take into account four key types of evidence about the pathogen, like how it is transmitted, to determine whether a strategy to eliminate the pandemic or merely control it is most appropriate.
Any strategy would have four common objectives, however, including stamping out chains of transmission where possible. Then, that strategy would be actioned with outbreak control interventions tailored to the pathogen and strategy in question – for the coronavirus, we locked down and wore masks, but something like pandemic influenza might rely less on population-wide measures.
Evidence at the root of the plan
The evidence relates: to the transmissibility of the virus and other infection dynamics; the severity of the illness and the likely effects on the population; how easy it is to control and the resource implications of doing so; and any uncertainty about the above three concerns.
“The defining feature of a pandemic is its ability to spread over a very wide geographic area, cross borders and affect a large number of people, so transmissibility (or potential transmissibility) is the entry point for assessing a pandemic,” the epidemiologists wrote.
Key dynamics to watch out for here are the incubation period, the reproduction number and the susceptibility of the population to the illness – many people have partial immunity to influenza strains, but not to the novel coronavirus, for example.
The severity of the illness is important for determining the impact on the population of different strategies. Understanding the transmissibility and the severity indicates how seriously officials should take the threat.
The third type of evidence processes the severity and transmission dynamics to determine how the pandemic might be controlled and what the implications of control attempts would be.
“Limiting factors in the initial Covid-19 response included lack of an integrated and rapidly scalable contact tracing system; concern about the surge capacity of the intensive care system; and lack of a vaccine and effective treatment modalities. These resource considerations were instrumental in the decision to implement a lockdown in March 2020, but this decision in turn required, and continues to require, provision of a range of support measures to mitigate the impact of this effective but high-impact approach,” the epidemiologists wrote.
Finally, the pandemic plan has to take into account varying levels of certainty. In the early phases of the Covid-19 response, much about the virus was still uncertain. Future pandemics could be equally novel or could be something we have more experience with, like pandemic influenza.
“There is a need to apply the precautionary principle when risks are not fully understood.”
As more information becomes available, Kvalsvig and Baker say, officials must be open to changing tacks.
Strategy and outbreak control
The four evidence types will then inform the strategy forward. Some pathogens – like Covid-19 or measles – can be eliminated, while others – like the flu – can only be mitigated or suppressed.
Regardless of the strategy, four main objectives are common to any pandemic response: finding and eliminating chains of transmission through case management, preventing undetected transmission through population controls (which can range from hand washing awareness to lockdowns), keeping the pandemic out of a region or country through restrictions at external and internal borders and reducing the susceptible population through vaccination.
Any individual outbreak should be targeted with efforts to reduce the effective reproduction number (the average number of secondary infections from an infected person) to below 1 with similar initiatives to decrease the ease of transmission for the pathogen, reduce the number of contacts the average person has and shortening or preventing infection.
In terms of next steps, Kvalsvig and Baker want the Government to conduct a review into the Covid-19 response to determine other important lessons. They want to see the existing pandemic plan revised in line with their recommendations and a national public health agency created to operationalise any future pandemic response.
“Decades of under-funding have resulted in a small and overstretched public health workforce with the result that the contribution of pandemic epidemiology expertise to the Covid-19 response has operated largely on donated time,” the epidemiologists wrote.
“One of the most valuable lessons we can draw from the Covid-19 experience in Aotearoa NZ is the importance of developing an agile response that is not constrained by preconceptions about what is and is not feasible to achieve.”