Health researchers say a deadly pandemic hitting New Zealand in modern times would be "impossible" to keep from spreading.
They are calling for a Government research fund to help prevent pandemics and prepare New Zealand to deal with such disasters.
A striking video of 440 students laid out on a school field has been made to illustrate the death toll on the deadliest day of the 1918 influenza pandemic.
The University of Otago Department of Public Health in Wellington organised the video to complement their study on the pandemic, which is published in the New Zealand Medical Journal today.
Professors Michael Baker and Nick Wilson co-authored the study, which examines what we know about the impact of the pandemic in this country, but also looks at aspects which have previously been ignored, such as the marked decline in the number of births the following year.
Wilson said this remained a "mystery" though could be attributed to higher rates of miscarriages and stillbirths due to the virus.
Other areas that needed further research included the impact of the pandemic on Māori, and whether poor people died at a higher rate.
"We have some idea that that was the case but that's an area that still could benefit from further research," Wilson said.
Instead of the national memorial planned next year for the thousands who died in the 1918 pandemic, Wilson said a research fund would act as a "living memorial" for the victims.
"It would be good to have something which had real substance and ... potentially could then save thousands of lives."
The pandemic struck in October 1918, just weeks before the end of World War I, and continued through November and December.
An estimated 9000 New Zealanders died of flu over the course of just eight weeks, equivalent to losing 37,000 New Zealanders as a proportion of today's population.
"It is important not to let this anniversary pass without remembering the terrible impact this pandemic had on the country – an event that was over-shadowed at the time by the First World War," Baker said.
At the peak of the pandemic, an estimated 440 people died in a single day, equivalent to 1820 deaths in today's numbers.
That large death toll is graphically illustrated by a photo taken at Wellington College of 440 year 9 and 10 students lying down on a school sports field.
"As researchers we are regularly quoting figures of people who become ill and die, but most of us have trouble even conceiving of these sorts of numbers," Baker said.
Wilson said New Zealand continued to face major threats, both from familiar diseases like pandemic flu, and from novel pathogens, which may be developed through new techniques, such as gene editing.
"If pandemic influenza arrived tomorrow it would be impossible to stop it spreading within New Zealand and it could be as lethal, or even more lethal, than it was in 1918," he said.
"It's a highly infectious disease."
Pandemics occurred just a few times each century, and the 1918 one was particularly severe, he said.
The speed of modern travel meant the virus could be carried across the country in very little time.
Access to respirators and intensive care units is limited, meaning many people would end up being cared for at home, where they were more likely to die.
"Other novel emerging infectious diseases, such as severe acute respiratory syndrome (SARS), a severe form of pneumonia, are an ongoing threat. Advances in synthetic biology, such as new gene editing tools, raise the potential for production of novel pathogens, which could be released accidentally or deliberately as bioterrorist weapons or weapons of war."
There should be plans in place to run quick mass media campaigns around basic hygiene, such as handwashing, coughing into a sleeve, and staying home if sick, Wilson said.
Closing the country's border could be the best option in an extreme pandemic, according to previous research from the same department, published earlier this year.
Baker said New Zealand needed to develop a better plan for "worst-case scenarios".
"Completely closing the border to prevent the entry of a pandemic would make sense from both a health and economic perspective if the disease was as severe as influenza in 1918."