These sneezes and snuffles may sound like the sufferers have all caught the same bout of flu. But although the symptoms are often similar, there are hundreds of different exotic flu viruses.

And not only that, the viruses constantly change, making the search for a cure almost impossible. That is until now.

The rapid rate of mutation of the flu virus has resulted in a continuous onslaught of new strains, like the 1918 Spanish flu which killed over 20 million people world wide, and the virulent and deadly Hong Kong flu of the 1960's, which came from chickens.

And each time scientists have developed a cure, a totally different flu has emerged.

So scientists from Australia's national science agency, Dr. Peter Coleman and Dr. Jose Varghese decided to find out what, if anything, did flu viruses have in common.

"Although the virus does change itself dramatically from year to year, there is a small part of influenza virus which is absolutely the same on every wild strain of flu that's ever been found"

What makes flues different from each other, are two proteins which cover the virus. These proteins are changed even more significantly if the strains have come from other species such as pigs or poultry.

However, what the CSIRO scientists found was a small pocket on the surface which is exactly the same in all types of flu and has never changed in the evolution of flu strains. So they set out find a way to plug this pocket with a designer drug molecule. It took five years, but finally they succeeded.

The result was the world's first successful influenza drug, called Relenza, which plugs the pocket and stops the virus from spreading.

"Relenza is an anti viral. Everything you've taken so far is a symptom relief medicine. Relenza also relieves the symptoms of influenza, but it does so by attacking the virus and not the symptoms themselves"

It has taken eight years of testing on animals and humans to ensure that Relenza not only works, it has absolutely no side effects. The development of Relenza is estimated to be worth at least two billion dollars a year. And it's worth every cent.