How likely is a flu pandemic?

The World Health Organisation puts the risk level at "phase 3" out of six on its pandemic alert scale, which means that a new flu strain has appeared in humans but is not yet spreading from person to person. It is impossible to predict when the next flu pandemic will happen, but experts say we are living on borrowed time.

The big worry is the particularly deadly strain of H5N1 bird flu circulating mainly in south-east Asia - so far it has infected 335 people and killed 206 (mainly poor farmers who live in close proximity with their poultry). If it were to mutate or swap genes with a human flu virus so that it was more easily transmitted between humans, we could face a pandemic.

by James Randerson for The Guardian

It is this scenario that prompted the government to bolster its plans for dealing with flu last week. Health ministers have ordered that the current stockpile of 14.6m doses of the antiviral drug tamiflu be increased by another 15m at a cost of around £150m. That will allow doctors to give the drugs preventatively to the families of people who become infected and not just people who contract the virus. Estimates of the number of people in the UK who would be killed in a future pandemic range from 55,000 to 750,000.

Last century there were three pandemics. The 1968-69 Hong Kong flu killed up to a million people globally, the 1957-58 Asian flu killed up to 1.5 million and the mother of them all, the 1918-20 Spanish flu, killed around 40 million - more than the first world war. There is no regular cycle governing pandemics, but the long gap since the last one is making experts jumpy. And since the last epidemic in 1968 air travel has become more common, meaning that if a pandemic virus emerged, it could spread around the globe more quickly.

NVDL: I once interviewed an expert at the University of the Free State, Professor Bragg. He said, 'There's basically diddly squat we can do about it'. I called that interview 'A Matter Of When'. I also attended a Tamiflu conference and the expert there, John Oxford, said the same thing.