COVID-19: How New Zealand Stopped Community Transmission

Back in March, California issued the country’s first statewide shelter-in-place order, mandating social distancing, restricting travel, and limiting public and private gatherings, all in an effort to slow the spread of COVID-19. By mid-April, 95% of the U.S. population had basically been instructed to stay at home. The disruption to daily life was severe, and the economic impact was staggering, with more than 40 million Americans filing unemployment claims.

There was, we were told, a method to this madness. The goal was to “flatten the curve” by reducing the rate of infection so as to prevent our healthcare infrastructure from being overwhelmed by demand for scarce medical resources, including intensive care unit beds and ventilators. In addition, these measures were also meant to buy us time to increase our testing capabilities, establish rigorous practices for contact tracing and isolation, and develop treatments and vaccines. We understood all too clearly that this was a very serious situation, but many of us still saw it as a short-term disruption, optimistically looking forward to a return to “normal” by the autumn.

Well, autumn has arrived, but normal has not. Testing for COVID-19 in the United States has increased in fits and starts, and contact tracing remain far below recommended levels [1]. While different states and counties have altered or lifted last spring’s restrictions, many schools and offices remain closed, and many of us continue to adhere to social distancing guidelines and travel limitations. To date, this virus has infected nearly 8 million Americans (and an estimated 38 million people worldwide) and killed more than 215,000 in the U.S. (and over 1 million globally).

And there is no clear end in sight. While there are currently 44 different vaccines in various stages of human clinical trials, the timeline for public availability remains opaque. Dr. Paul Offit, a professor at the University of Pennsylvania and a member of the U.S. FDA’s vaccine advisory panel, recently stated that “the more responsible answer is, ‘Hopefully, we’ll know something by the beginning of next year.’ That would seem to me to be the most likely scenario” [2].

New Zealand’s Impressive Response

As the days and weeks and months have dragged on, I have come to accept that there is little to be done beyond making good personal choices while we wait for science to help us find a way out of this crisis. Though every day seems like another Tuesday, I am grateful for my family’s health and well-being, and am generally plodding along with as much positivity as I can muster.

Or at least I had been, until the other day when I got an email from my college friend Karen, who has been living in New Zealand for the past 30 years. “I think of you often and wonder how you are doing,” she wrote. “I don’t even want to tell you how ‘normal’ my life is right now – it just seems smug – New Zealand has taken a huge economic hit, but we are doing well. No community transmission. We have been told to prepare and be ready should another outbreak occur...”

How did they do it?

New Zealand certainly has some unique advantages when it comes to addressing COVID-19, including geographical isolation, a political system that tends toward governing coalitions, a relatively strong central government, and a population of just under 5 million. Prime Minister Jacinda Ardern also deserves a great deal of credit for her decision to implement an aggressive “go hard, go early” [3] response to the pandemic, courageously implementing significant restrictions on a nationwide basis even before the country had experienced a single fatality.

The results have been impressive. New Zealand first managed to fully eradicate the virus by mid-June, slightly more than three months after its first confirmed case and slightly less than three months after its first set of restrictions were imposed. More recently, after a few new cases emerged this August in Auckland, Ardern’s government once again moved swiftly to lockdown the city, implement aggressive testing and tracing, and ultimately stamp out the virus for a second time in less than two months. Today, the only restrictions still in place are fairly tight border controls. Bars, schools, churches and sports stadiums are full while the public is encouraged to take advantage of world-renown tourist destinations. The economic pain, which had clearly been intense during periods of lockdown (and had been partially eased through an expansive government aid package), is expected to ease now that New Zealand has largely resumed its normal social and commercial activity.

The success of Ardern’s COVID-19 strategy is seen as a pivotal factor in the recent election, where voters resoundingly granted her a second term as prime minister. By all accounts, a crucial underlying element of New Zealand’s successful response to COVID-19 has been a commitment to truly following the science. Intrigued, I reached out to Dr. Kevin Ross, director of research at Orion Health and CEO of Precision Driven Health [4], a New Zealand-based partnership that connects researchers, medical institutions and healthcare IT providers. Dr. Ross was kind enough to fill me in on some things that had not made their way into the international newspapers.

Modeling the Spread

Ross began by introducing me to Te Pūnaha Matatini [5], New Zealand’s Centre of Research Excellence for Complex Systems. Back in March, an early research paper by Shaun Hendy (director of Te Pūnaha Matatini and professor of physics at the University of Auckland) and several colleagues sought to examine the potential impact of various suppression and mitigation strategies by modeling the spread of the virus using New Zealand-specific parameters [6]. Soon thereafter, Hendy’s team was asked by the government to take the lead on modeling the spread of the disease, partnering with Ross and his team at Orion Health. “We’d been working together before in various ways,” Ross explained. “Everyone sort of knows everyone in the field down here.”

One key to making all of this work: timely access to new data. Indeed, the seriousness of the situation, along with the imprimatur of the government, literally led to healthcare data providers being served with warrants by the police (“It took quite a while to smooth over some ruffled feathers from that,” Ross admitted). The daily flow of updated data has enabled parameters to be updated and models to be refined on a regular basis.

There has also been an equally steady stream of information flowing from the modelers to the policymakers. Model results, insights and updates were provided on a daily basis to the National Crisis Management Center, which in turn synthesized input from multiple sources into a daily briefing presented to the Ministry of Health and the prime minister.

The influence of the modeling work on the policy process would prove to be significant. In April, analysis by Hendy and his team suggested that preventing another outbreak of the virus would require the most severe (“Level 4”) restrictions to continue beyond the initial four-week period; in May, the Level 4 restrictions were indeed extended for an extra week. And earlier this month, Prime Minister Ardern sounded almost like a Bayesian when noting there was a 95% probability that the country had eliminated local transmission of the virus for a second time [7].

To be sure, New Zealand’s battle with COVID-19 has been more challenging than it might appear to outsiders. In particular, getting the entire nation to comply with its social distancing policies has not been simple, in part because New Zealand’s culture of individualism is similar to that in the United States, as shown in the research of cultural psychologist Michele Gelfand [8]. In our conversation, Ross noted that the government’s primary response to transgressions was to issue warnings and provide education and encouragement. “The message was that ‘the virus is the problem,’ not the people,” he explained.

Finally – and not surprisingly – Ardern’s critics have claimed that her government’s restrictions have been more severe than necessary, asserting that overly draconian policies have caused unnecessary economic hardship. In a blog post back in April, Ross had anticipated this very type of criticism: “We test scenarios because they could happen, not because they will. We often build models with the aim of being wrong. We predict hospital admissions in an effort to avoid them. We believe that data-driven decisions are better than the alternative. With COVID-19 you will see data science tested and sometimes seem to be off the mark. Perversely, the more we listen to the models and the better we respond, the more it may seem that we overreacted” [9].

None of this is easy.

References

1. https://www.scientificamerican.com/article/contact-tracing-a-key-way-to-slow-covid-19-is-badly-underused-by-the-u-s/
2. https://www.nytimes.com/2020/09/17/health/covid-vaccine-when-available.html
3. https://journals.sagepub.com/doi/pdf/10.1177/0275074020941721
4. https://doi.org/10.1287/LYTX.2019.05.11 
5. https://www.tepunahamatatini.ac.nz/about-us/
6. https://www.tepunahamatatini.ac.nz/2020/03/26/suppression-and-mitigation-strategies-for-control-of-covid-19-in-new-zealand/
7. https://www.nytimes.com/2020/10/07/world/australia/new-zealand-coronavirus.html
8. https://www.michelegelfand.com/rule-makers-rule-breakers
9. https://precisiondrivenhealth.com/whats-in-a-model/