Beyond elimination


Sir Peter Gluckman

As the Global Covid Scenarios project gets underway, it is worth reflecting on New Zealand’s current and future strategy in dealing with the pandemic. I have been surprised how many think we can live with elimination as a permanent strategy: it is not realistic long-term.

After some initial discussion about ‘flattening the curve’, New Zealand made the appropriate and definitive decision early on to follow an elimination strategy.  This came after Sir David Skegg, in his first expert presentation to the Epidemic Response Committee, pointed out the need for real clarity as to what was the strategy that the government would be following. This choice reflected the reality that New Zealand had relatively little burden from the virus and could therefore shut its borders and eliminate the virus via tight quarantining of arriving travellers, combined with increasingly effective contact tracing and testing.  As was inevitable, there were several temporary lockdowns required when incursions across the quarantine border occurred.

Australia followed a similar path as did a number of island states including our neighbours in the Pacific. Some started down this path and later chose to abandon it because it failed or because of economic and social pressures, such as reopening the tourist industry (e.g. Jamaica).  In general, the elimination approach has been more difficult for countries with contiguous land borders. Still, some other countries such as Rwanda, Vietnam and Cambodia have largely kept the viral invasion at bay.

For a country such as New Zealand to aggressively pursue an elimination strategy has been logical.  However, while it was easy to start down such a path and sustain it for over a year, it is apparent it cannot be continued indefinitely unless we are prepared to stay indefinitely with tight border controls, vaccine passports and some forms of quarantine. Vaccination protects against severe forms of the disease, but while it reduces transmission it does not absolutely stop the vaccinated individual carrying the virus. The much harder, and ultimately unavoidable decision will be when and how to move beyond eliminating the virus through tight border controls and potentially accept a level of endemism with its consequences – especially for those who are not vaccinated.

The arrival of the vaccine in New Zealand must herald a discussion of how we shape the path ahead. In a few months, a large number of New Zealanders will be vaccinated and the risks of severe disease for those who receive vaccines much abated. But even when sufficient vaccine is available, not all New Zealanders will choose to be vaccinated – some will refuse on philosophical grounds, others will fall victim to misinformation, and there will be other rationales or beliefs presented by individuals who refuse vaccination.

Thus, the politically difficult decision will be at what point will there be enough vaccine protection within our population to relax the elimination approach. And this is not simple and not solely a scientific question.  There will be questions about whether the basis of such a decision will relate to a given percentage of all New Zealand residents being vaccinated and indeed by which vaccine?   Will the change be when our most at-risk populations (e.g. those with or at risk for type two diabetes) are near-fully vaccinated?  And as the vaccine rollout progresses, it is understandable that business, economic and social pressures on the government to ‘open-up’ will grow. As a backdrop to all of this, the virus may further mutate, creating a moving target. It may mutate in ways that make the current vaccines, or at least some, less protective.

Opening our borders raises other issues that would need resolution. Would we only open up to vaccinated individuals or do so at least initially and even then, on what basis? The current conversation about vaccine passports is largely being driven by individual countries and airlines – it is a critical issue for New Zealand to think this through and be part of the conversations. As New Zealanders start to travel again, it must be recognised that the vaccine will not protect absolutely against the virus moving with them.

So it is it inevitable that border relaxation and then complete opening (which effectively represents the end of the elimination strategy) will happen at some stage. The only alternative would be some version of the current arrangements sustained indefinitely – even if only for some countries. This is likely to create some complex geopolitical divides and is ultimately unrealistic, even if it may be an interim step. Increasing the use of rapid tests, passive contact tracing, vaccine certificates, and self-isolation for shorter periods might allow some people across the border in managed numbers in the near future with a very low risk, as has been achieved in Taiwan. However, once our borders open, some virus will enter the country. Therefore, it is only by effective vaccine coverage that we will continue to keep the level of viral risk below a ‘damage threshold’.

It is unrealistic to expect long-term absolute elimination across the globe. That has only been once achieved for a human virus – in the case of smallpox. As the Covid virus now has a vast human reservoir and mutating base and given the realities of the Global South it will take many years to vaccinate the global population. Moreover, it is also present in some companion and wild animal populations. Thus with border opening, whatever the checks, the virus will enter. However, on a more positive note, there is no doubt that therapeutic medical approaches to this disease will continue to progress and reduce the levels of morbidity and mortality caused by Covid-19.

Ultimately against this background, the most likely scenario is one in which Covid eventually becomes like influenza: namely a virus that will require periodic immunisation of the population (or at least the high-risk portion) and societal acceptance that it will lead to at least some low level of illness, especially in those not vaccinated.

The pathway for New Zealand to get beyond its gilded cage depends on an aggressive rollout of vaccines. Even as it is, maintaining an indefinite elimination strategy will inevitably lead to periodic lockdowns, and these will be associated with increasing economic unease and rising mental health concerns, progressive educational disruption, and general frustration.

As widespread vaccination will clearly take time, the question becomes are there intermediate measures that could offset some of the ongoing social and economic damage? For example, some decisions could open the Trans-Tasman bubble (see my next essay on Covid and diplomacy). However, such an opening would still mean accepting periodic, potential regional lockdowns on either side of the Tasman.

The government has done a universally and deservedly well-praised job through its choice to follow an elimination strategy. Up to now, it has kept the population well onside. But it will risk backlash if it does not start discussing openly and transparently its considerations about moving beyond elimination. The arrival of vaccines makes such a discussion inevitable.