Restrictions on overseas travel restrictions and gatherings of more than 100 people would remain in place under their plan, titled "Plan B". But Professor Nick Wilson, of Otago University's Department of Public Health, said modelling showed New Zealand could have experienced horrific scenes of COVID-19 mass graves if the country had moved slower to lockdown and the virus had got out of control. Prime Minister Jacinda Ardern and Director-General of Health Dr Ashley Bloomfield explaining the Government's response to the pandemic. Credit:Getty Images The elimination strategy, advocated by Wilson and some of his colleagues, has been central in informing the government's approach to coronavirus pandemic. Wilson said an alternative option was the suppression strategy, which uses controls such as different levels of lockdown.

"And it is very hard to get that right because it is a pretty infectious disease," he said. Loading The third option was the mitigation strategy, which Sweden had taken. This appears to be the approach advocated by the "Plan B" group, he said. It allows the virus to spread slowly without overwhelming the health system while moving towards herd immunity. However, he warned this approach had led to a higher number of deaths in Sweden compared to its Nordic neighbours.

Sweden also has much more ICU capacity than New Zealand and if the government followed Sweden's example "we would be having lots of deaths on the floor of the hospital," he said. Wilson called for the group to publish modelling and evidence to justify its claims. "Every public health doctor is concerned about the impact on society of the lockdown but if we do eliminate it quickly we can open up the economy much earlier than other countries and use border controls as a means of keeping it out. "As an island nation we have much better options if we keep that quarantine until we have a vaccine.

The alternative plan was developed by Auckland University's senior lecturer of epidemiology Simon Thornley. "Lockdown was appropriate when there was so little data ... but the data is now clear, this is not the disaster we feared and prepared for. Elimination of this virus is likely not achievable and is not necessary," he said. Thornley said the risk to most working people was low and likened it to a seasonal influenza virus. He said the plan was developed amid concern the government's strategy was over-the-top and likely to "substantially harm the nation's long-term health and wellbeing, social fabric, economy and education". Other members of the group include Grant Schofield, professor of public health, Auckland University of Technology; Gerhard Sundborn, senior lecturer of population and pacific health, Auckland University; Grant Morris, associate professor of law, Victoria University; Ananish Chaudhuri, professor of experimental economics, Auckland University; and Michael Jackson, postdoctoral researcher in biostatistics and biodiscovery, Victoria University.

No deaths had occurred among New Zealanders under 70 and much of the modelling related to the mortality associated with COVID-19 was overestimated, the group said in a statement. The real threat posed by the virus was it would overwhelm the health system but New Zealand's risk was lower than in other countries with higher population density, and the local health system had spare capacity, they said. "Data shows a large majority of COVID-19 fatalities have occurred in people due to their co-morbidities rather than directly from the virus. Even in Italy only 12 per cent of cases were directly due to COVID. "If you catch COVID-19 your likelihood of dying is the same as your average likelihood of dying that year anyway. It has been described as squeezing your year's mortality risk into two weeks." Sign up to our Coronavirus Update newsletter Get our Coronavirus Update newsletter for the day's crucial developments at a glance, the numbers you need to know and what our readers are saying. Sign up to The Sydney Morning Herald's newsletter here and The Age's here.