American public health emergency expert Dr John Pournoor will deliver a National Press Club address on Tuesday on ''Global biosecurity - preparing for the next pandemic''.

He believed Australia was ''reasonably well prepared'' for such a disaster but the public needed to consider whether it wanted more taxpayer investment on "insurance" against a health crisis that would inflict a big death toll.

Dr Pournoor, who leads the 3M Avian Flu Public Health Solutions Program in the US, has also helped develop strategies for combating public health threats across Europe and the Asia Pacific region, spending much of the past decade focusing on drug delivery, biological detection, infection control, epidemiology and emergency response.

Dr Pournoor said how well a country was prepared to face an epidemic and how much public funding should be devoted to combating a potential threat was "one of the toughest public policy dialogues to have".

Australia was one of only nine countries in the world that had the ability to manufacture vaccines and this was an important asset in a future pandemic.

More widely, flu vaccines continued to be critical in fighting off a pandemic.

But the problem was vaccines could not be engineered until the pathogen had emerged in the community, which left people vulnerable in the early stages of an outbreak.

Dr Pournoor said three of the top five biggest death toll events in Australia's history were due to epidemics - including influenza, bubonic plague and polio. One of those epidemics, the Spanish flu of 1918, killed more than 12,000 Australians when the population was only 5 million.

"Infectious disease outbreaks are unique events. A bushfire, as devastating as it is often, is regionally contained. A chemical spill only affects the immediate area of the spill for a certain radius. Cyclones can be tracked by radar. Then we hunker down, they come and go, and we rebuild," he said.

"However, infectious disease outbreaks are a different story. For influenza, you can be a carrier without symptoms, you board a plane in one country and hours later you land in Australia. And you are a silent asymptomatic transmission vector."

The best public health initiatives included educating the public on disease prevention, including avoiding public contact during an outbreak.

Australia's federal, state and territory governments needed to co-ordinate their efforts to ensure essential services were maintained in a catastrophic event, while health workforces on the front line needed to be protected and trained in order "to keep showing up for work when they are in the middle of an emergency".

"After working in almost 40 countries on national emergency plans including as many pandemic plans, an observation I can make is that in every country there is an unspoken social contract between government and citizens … about what the citizens expect to see should disaster strike the country.

"The challenge with pandemics is that they are rare yet devastatingly catastrophic and the public policy challenge is how do you allocate resources to prepare for events that happen one to two times a century yet are devastatingly lethal?"