Model advice

Concerned by how disastrous the coronavirus outbreak could become, Professor Nick Wilson and his team have modelled real-world data throughout the pandemic crisis, providing vital information for government.

In contrast to many public health systems, Professor Nick Wilson was well-prepared for the COVID-19 crisis.

Wilson works with the Health, Environment and Infection Research Unit (HEIRU), at the University of Otago's Wellington campus, and has a long-standing interest in researching pandemics.

He and epidemiology colleague and HEIRU director Professor Michael Baker were the first to alert the government to how many New Zealanders might die if officials made the wrong calls.

In late March, their team estimated 8,600 to 14,400 deaths as being plausible. The worst-case scenario – letting the virus run its course through the population without intervention – had suggested a death toll of 28,000.

Intervention was vital, but finding the right way to tackle the virus still demanded careful modelling based on the data to hand and the limited understanding of the virus at the time.

Wilson had modelled influenza pandemics in 2009 with German colleagues. They amended their work to a COVID-19 model and Wilson fine-tuned it with New Zealand parameters to give timely advice to the New Zealand government, continuing to do so throughout the crisis.

“Our best estimates turned out to be what has played out around the world,” says Wilson. “As the outbreak progressed we could update our models because we had much better real-world data to work with. But there's still a lot we don't know.”

As director of the Burden of Disease Epidemiology, Equity and Cost-Effectiveness Programme (BODE3), Wilson researches potential preventive strategies for disease control, although this is usually for chronic diseases.

The programme estimates the impacts of health sector interventions on public health and wider societal gains, with costs and economics layered on top. The aim is to grow knowledge, reduce inequalities and build capacity.

That capacity was sadly lacking when the new coronavirus appeared, despite years of warnings from Wilson and other public health scientists about under-investment. After decades of neglect, fragmentation and erosion, New Zealand's public health infrastructure was failing long before COVID-19.

“In early February we warned that the pandemic could get very bad. But it became much easier to convince officials of the urgency to act because of what was happening in Italy, which was struggling with the pandemic despite having better hospital capacity and more ICUs per population than New Zealand. If our government had delayed by just another week we could have lost control.

“Eventually New Zealand did a great job with the lockdowns and instigating border controls, but could still have acted faster and avoided some border control mistakes. If we had been better prepared and done what Taiwan had done we might have been able to avoid lockdown altogether. Sadly, we didn't follow Asia's lead until the situation in Italy got out of hand.

“A lot of Asian countries had learned from the SARS pandemic, getting used to wearing masks and setting up good health service infrastructure to cope. New Zealand had not learned anything from SARS, despite warnings from public health scientists of a re-emergent SARS or another coronavirus. That was disappointing.

“We need to learn from past pandemics even if they didn't hit us so we are ready for them if they arise again. We need to have people warning of the dangers, people listening to those warnings and then people putting solutions into operation.

“In future we could be facing much worse things than influenza or coronaviruses – synthetic biology could be used to develop bioweapons or disease agents. So we have to take these opportunities to gear up our systems before worse things arrive.

“Unfortunately politicians can be short-sighted. The chronic problem of governments is that if it's not an immediate crisis, it's too hard to devote resources to it. It's like our response to tobacco. We've known for 60 years that it is a killer, but we are still fighting it. There is pushback from the tobacco industry, but you might expect some progress from systems to control pandemics given there are no vested commercial interests.”

“With New Zealand's international status high at the moment, the country could push for desperately needed international co-operation…”

Wilson acknowledges that the eventual response from the government and its team of five million during lockdown and the actions towards eliminating COVID-19 were very successful.

“Achieving one of the lowest death tolls per capita in the western world rates an eight out of 10, but when considering the lack of preparedness, New Zealand is not such a shining example. Taiwan was so well organised that it didn't even need a lockdown. Our action has been effective, but at a huge economic cost.”

The lockdown experiences that stalled the economy also pressed pause on normal life, giving many a new perspective to consider.

“The forced experiment of lockdown on New Zealand society showed how much 'normal' life contributes to air pollution. It's given us insights into the benefits of walking and cycling on near-empty streets, working from home, using video-conferencing to replace travel, and even home vegetable gardening.”

Our challenge now, says Wilson, is to invest in some of these things in the post-pandemic world, reducing travel with new walking and cycling infrastructure, online conferencing, home offices and online health-care consultations.

“The government's 'green reset' recovery package is a start. Waterway restoration, pest control and nature-based jobs have potential co-benefits for public health, reducing risks of bowel cancer [from nitrates in water] and diseases spread by animals.”

The post-pandemic economic crisis offers major opportunities for advancing public health, says Wilson. Prophylactic taxation could support government spending on green initiatives and protect both the environment and health.

“Tax reforms could include a fertiliser tax, a pesticide tax and higher carbon taxes, as well as higher or new taxes to reduce exposure to activities and substances proven to be harmful to health: tobacco, alcohol, gambling, sugary drinks and junk food.

“With New Zealand's international status high at the moment, the country could push for desperately needed international co-operation, seeking to strengthen the World Health Organization and encourage global efforts to produce and distribute a vaccine against COVID-19. Further initiatives against pandemic threats should include strengthening the Bioweapons Convention, eliminating wildlife trade and abolishing wet markets.

“We need to strengthen institutions such as the United Nations so we can better tackle climate disruption and other catastrophic threats, the two most critical potentially being pandemics from synthetic biology and that posed by artificial intelligence. These cannot be effectively managed by individual jurisdictions acting alone.”

While emerging opportunities for advancing health and environmental protection may take time to consider, Wilson is now modelling possible costs and benefits of New Zealand opening borders with Australia, evaluating various control interventions such as screening, testing and quarantine.