New Zealand has only a small stockpile of anti-viral medication, but the Health Ministry says it is well prepared to cope with an outbreak of new and virulent influenza.
"International experts have long believed that another influenza pandemic is inevitable, and that the question is one of when rather than if," acting director of public health Doug Lush said.
Outbreaks earlier this year of H5N1, a particularly virulent bird flu, in many parts of Asia had raised fears it could mutate into a new strain and cause a human flu epidemic.
"Where a new virus arises that no-one has ever experienced before, there tends to be very high rates of infection and sometimes this can be very lethal," Dr Lush said.
New Zealand had a small stock of anti-viral medication, bought as part of the Ministry´s response to H5N1 early this year.
"Antiviral drugs may be useful in some situations but the costs and the limited shelf life means that stockpiling large amounts is not a simple matter. We need also to bear in mind that historically most people who become infected with pandemic strains of influenza recover and are immune to re-infection."
The Health Ministry has just published a National Health Emergency Plan for infectious diseases which gives a framework for responding to high impact, fast-moving diseases.
"Although we would hope to avoid one, with international travel it would be impossible for a country like New Zealand to completely avoid a pandemic.
"The better prepared we are, the better our chances of managing the impact such an event would have."
Dr Lush said three recent deaths from avian flu in Vietnam did not present a major risk to New Zealand travellers.
They are the first officially confirmed cases of the disease since an outbreak in the region in February.
He said tourists in affected parts of Asia, such as Vietnam and Thailand, should avoid contact with live poultry and chicken faeces.