Health conditions

Flu (influenza) pandemic

What is a pandemic?

A pandemic occurs when a disease or virus becomes geographically widespread throughout the world.

What is pandemic influenza?

Pandemic flu is a global outbreak of flu. This occurs when a new strain of the flu virus, against which people have little or no immunity, spreads rapidly from person-to-person.

Pandemic flu virus may cause illness of varying severity.

Some pandemic viruses have caused illness of similar severity to that seen with seasonal flu.

However, because more people catch the flu during a pandemic than in a usual year, there are higher overall numbers of people requiring hospitalisation or in severe cases, dying.

Pandemic flu in Australia

There have been several flu pandemics that have affected Australia, including the Spanish flu (1918), Asian flu (1957) and the Hong Kong flu (1968).

The most recent was the 2009 swine flu pandemic.

Swine flu pandemic

A new H1N1 virus derived from human, swine and avian strains of flu was initially reported in April 2009 in Mexico.

The virus subsequently spread around the world.

In Australia during 2009, there were 37,636 reported cases of pandemic (H1N1) flu 2009, including 191 associated deaths.  yes

On 10 August 2010, the World Health Organization (WHO) (external site) declared a global end to the 2009 H1N1 (human swine flu) pandemic.

Although we are no longer in a pandemic state, it is expected the swine flu virus will continue to circulate globally as a seasonal virus for years.

The current flu vaccine offers protection against the swine flu virus, along with two other flu viruses. Single vaccines specifically for swine flu are no longer available.

Preparations for pandemic flu

Australia is currently in the ALERT phase of our pandemic plan. This is consistent with the WHO's recommendation for ongoing vigilance during the post-pandemic period.

The Department of Health has a detailed pandemic plan to ensure we manage any threat to public health in Western Australia.

Is there a vaccination for pandemic flu?

A vaccine that provides protection against any new pandemic flu virus can only be developed after the new virus strain appears, and this can take several months. It is also likely to mean that any vaccine produced will initially be in short supply.

The Australian Government has arrangements to develop a suitable vaccine if a new strain of pandemic flu virus emerges.

Vaccine manufacturers are contracted to the government to ensure that if there is a flu pandemic outbreak there will be enough vaccine produced and available for all Australians. 

More information

If there is an outbreak of pandemic flu in your community

  • Check the Healthy WA website for updates.
  • Watch TV, listen to the radio or check newspapers for up-to-date information.

Pandemic outbreaks in foreign countries

If you are travelling to or residing in a country that may be affected by pandemic flu, visit Smartraveller (external site) to find out more information.


  • Pandemic flu is different to seasonal flu in that it usually involves a new strain flu virus (or a past strain from many years ago). The result is that most people will have immunity to this virus.
  • Pandemic flu is a worldwide outbreak of a flu virus in the human population.

Public Health

See also

Link to HealthyWA Facebook page