Covid-19

NZ’s new Covid-19 strategy explained

The Government has embraced a new strategy after reviewing a scientific paper that called for intense social distancing to avert tens of millions of deaths worldwide

New Zealand is the latest country to change its thinking about Covid-19 after reviewing a groundbreaking scientific paper from Imperial College London.

The paper, from the Imperial College London's Covid-19 Response Team, led by Professor Neil Ferguson, found incredibly stringent measures were needed to prevent mass death.

Director-General of Health Ashley Bloomfield confirmed he had read the paper and that New Zealand had altered its policy in response to its conclusions. Minister of Health David Clark said he had received advice on the paper.

New policy in place

Previously, the country had been focused on flattening the curve - slowing the spread of cases and minimising the extent to which the peak of the pandemic would exceed New Zealand's healthcare capacity.

Now, the country is planning to implement strict controls to manage any outbreaks and suppress them to the point that they do not exceed system capacity. New Zealand no longer plans to manage the pandemic as a single wave, but to instead repeatedly snap stringent measures into place and reduce Covid-19 to a series of smaller waves.

"Our approach - and this is what successful countries have been doing - is you want to have a series of small peaks over a longer period of time and you amplify up quite stringent controls to ensure that you don't exceed your health system capacity," Bloomfield said Wednesday. "Then as it goes down again, you can ease those and be prepared to ramp them up again."

"This is what looks to be the most successful strategy. What we have been able to do in New Zealand is buy ourselves time to look at what is successful and then apply the right interventions at the right time."

Bloomfield said the paper "was very critical in our response over the last few days to inform our shift from a 'flattening the curve' to a series of smaller curves. What they were able to do was identify what measures you need to take to not just flatten the curve but to keep any outbreaks at a level that your health system can still cope with and that's the position we want New Zealand to be in."

Clark told reporters he was aware of the paper when he announced the Government's new indoor gatherings policy, which bans events of 100 or more people.

"Indeed, the idea that we lower the curve but also try and suppress it - flatten and suppress - is one that I'm aware that Cabinet is actively considering how best we implement. And indeed, that thinking is informing the decisions we're making: for example, the decision today," he said.

"The Imperial College advice, which people will have seen, suggests that flattening the curve will be a challenge for even the most prepared health systems in the world and that it is advisable, if at all possible, to lower the rates to ensure - in line with the strategy we've been taking - that we contact trace all cases and that we ensure that we don't get widespread community outbreaks."

Suppression the only option

The paper, which Newsroom analysed on Wednesday evening, predicted the United Kingdom and the United States would see 510,000 and 2.2 million deaths, respectively, if they took no action to fight Covid-19.

However, the paper also concluded deaths would remain in the hundreds of thousands and the millions for the UK and US respectively if weaker measures to merely mitigate the virus were taken. Both countries altered their policies after receiving a draft copy of the paper, the Washington Post reported.

Instead, in the event of widespread community transmission, stringent suppression policies were needed to reduce deaths to a minimal level and keep the number of patients requiring intensive care within the capacity of each country's healthcare system.

Such measures would include the mitigating policies - self-isolation for symptomatic cases and their families - as well as a degree of social distancing that would reduce all contact outside the home, school or workplace by 75 percent. In workplaces, contact rates would drop by a quarter as more people work from home and offices put in place protective measures to minimise physical contact. Alongside this, all schools would shut, as would 75 percent of universities.

"The major challenge of suppression is that this type of intensive intervention package – or something equivalently effective at reducing transmission – will need to be maintained until a vaccine becomes available (potentially 18 months or more) – given that we predict that transmission will quickly rebound if interventions are relaxed," Ferguson writes in the paper.

In other words, the New Zealand Government has accepted that, if community transmission becomes widespread, it will have to lock down the country for a period of 18 months.

There's some flexibility here: With appropriate monitoring of hospitals and communities, countries could reopen schools and ease social distancing requirements whenever the number of ICU beds occupied by Covid-19 patients dropped below a certain number. In the UK, for example, that number would be 50. If the number of patients in ICU then rose to 100 again - as researchers say it would - those requirements would snap back into place.

In other words, that's two months on intense social distancing, one month off - for the next 12 to 24 months.

Otago University Department of Public Health's professor Michael Baker says that's something New Zealand might need to prepare for - psychologically as well as logistically.

"It’s one thing to hear about it and see it happening at a distance. It’s like watching a Netflix series from overseas, but actually, that will be us if we don’t contain it," he said.

"It’s a new way of living that’s pretty foreign. It’s pretty obvious that no one alive today has seen a pandemic like this."