Latest analysis: Covid Delta surge in vaccinated societies shows masks are here to stay
As the Delta coronavirus variant causes thousands or tens of thousands of cases a day in countries ranging from Israel to Japan and the US, another nation is dealing with an outbreak of a very different scale.
New Zealand is in a strict lockdown introduced initially because of a single coronavirus case detected last week – an uncompromising response that reflects the country’s elimination strategy for Covid-19.
There have been 63 new cases of Covid-19 recorded in the community in the past 24 hours, taking the total number of active cases to 210, the highest figure since April 2020, as the web of contacts linked to the first person to test positive expands.
University of Otago, New Zealand
Thanks to intensive contact tracing, testing and isolation, experts believe the country will, however, be able to stamp out this current outbreak, even if doing so takes several weeks.
The elimination strategy of the government led by Jacinda Ardern, the prime minister, contrasts with the suppression or mitigation approach used by many other countries, which is based on vaccination and more limited lockdowns. New Zealand has fully vaccinated about 23 per cent of its population, the lowest of the OECD group of developed countries.
Australia and Singapore have also adopted the elimination approach to Covid-19, and plan to continue until high vaccination rates enable a move to a policy of suppression – living with the virus. But will New Zealand follow a similar strategy?
Benefits of the elimination strategy
Elimination has downsides, including a significant effect on New Zealand’s international tourism industry.
Even New Zealanders have found it difficult to return to their home country because of the strict border controls imposed to keep the country Covid-free.
But there have been significant upsides, not least the lowest mortality rate in the 38-member Organisation for Economic Co-operation and Development (OECD), with only 26 deaths recorded.
This is a tiny fraction of the number seen in many nations and is extremely low even after taking into account the country’s modest population of about five million.
At home, New Zealanders have typically enjoyed more freedom than their counterparts in other developed countries since the coronavirus emerged. Concerts and sports matches have taken place without the need for social distancing or masks.
The country’s economy also recovered faster than that of most OECD nations, although continued lockdowns could cause a reversal in economic fortunes.
A study published in May found that after disruption during the lockdown early last year, vital hospital services in the country, particularly cancer treatment, had not been heavily affected by the pandemic, helped by the fact hospitals were not overwhelmed by Covid-19 cases.
Can elimination continue for ever?
Opinions on whether New Zealand can maintain its strategy is divided. Some experts outside the country think that, in the long term, elimination is unrealistic.
Prof Eskild Petersen, an infectious diseases specialist at Aarhus University Hospital in Denmark, suggests that his country’s experience indicates that, with high vaccination rates – about 70 per cent of Denmark’s population is fully vaccinated – it is possible to live with the virus.
"In Denmark we have about 1,000 cases per day. The schools are open. There’s no longer a mask mandate in public spaces. People get infected, but hospitalisations remain low,” he said.
"The strategy of New Zealand – a nationwide lockdown – is very, very expensive compared with our strategy, where we have immunised as many people as possible as fast as possible.”
The relative benefits of an elimination strategy will decline, according to David Taylor, professor emeritus of pharmaceutical and public health policy at University College London.
“In time, if the world is going to normalise – and it will – we will probably get better vaccines produced and better drugs. At that stage, the advantages of trying to run an isolation policy fade away,” he said.
What will New Zealand do?
While New Zealand has indicated that it could begin to open up to the world next year, it has not said that it will abandon its elimination strategy.
Travellers entering the country will be treated according to the risk level of the country they are coming from, with some having to undergo managed isolation and quarantine.
This scheme, in which those arriving have to isolate in particular hotels on arrival, has been key to preventing the coronavirus from entering New Zealand.
Experts in the country said it is not clear how the coronavirus will affect health in societies over the long term.
It may become an endemic virus with a low-level impact, or it could impose a significant continuing disease burden.
Until the outcome becomes clear, they argue, it may be sensible to maintain elimination, a strategy popular with New Zealanders, according to reports.
Are regular lockdowns sustainable?
When more people in New Zealand are vaccinated – currently only about one in five residents are fully jabbed – it may be possible to continue with elimination even when “easing up on border controls” next year, suggested Prof Nick Wilson, of the department of public health at the University of Otago in New Zealand.
“It will mean that outbreaks arising from imported cases become more feasible to control,” he said. “Travellers to New Zealand will also need to be vaccinated, so that will help.
"But if the elimination strategy requires regular lockdowns to control outbreaks, then it may not be sustainable in the long term, given that the public acceptance of lockdowns will decline, as it is starting to in places like New South Wales in Australia.”
As well as preventing illness and death from Covid-19, the elimination strategy stops health services from becoming overburdened during coronavirus outbreaks, Prof Wilson said.
When hospitals are overwhelmed by Covid-19, treatment for serious conditions such as cancer or heart disease can be affected.
Prof Wilson cites modelling, which indicates that, even with high vaccination coverage, New Zealand’s health system could become overloaded.
"Many other measures for Covid-19 control are likely to persist in 2022, for example extensive community testing, extensive wastewater testing and mask use requirements on buses,” he said.
As it vaccinates, New Zealand is continuing with austere control measures and giving itself time to decide on a long-term approach.
After all, as Ms Ardern has noted, once elimination is abandoned, there is no going back.
