Search for secrets of killer flu

The flu virus: New variations emerge each year

The remains of 10 Londoners who died of "Spanish flu" during the outbreak of 1918 could yield clues to what made the virus so deadly.

Scientists have applied to exhume the victims' bodies, in a bid to decode the bug's genetic make-up.

We want to read the gene of the virus that killed 30 million people

Professor John Oxford, Queen Mary's School of Medicine

The 1918 Spanish flu was one of the most contagious viruses ever known. It killed as many as 40 million people in the winter of 1918 and 1919, more than died in the First World War.

Studying fragments of the virus, a dangerous type A influenza strain, could help experts prepare for new outbreaks.

The last time a type A strain struck in Britain; 20,000, mainly elderly, people died.

Genetic clues

A team led by John Oxford, the UK Government's flu adviser, has identified 10 victims of the virus that were buried in lead coffins across London.

He believes their bodies may be so well preserved that researchers will be able to extract the virus.

Flu is most dangerous in the elderly

Professor Oxford, of Queen Mary's School of Medicine, London, said there were opportunities using molecular biology to recreate the virus or at least look at its genetic make-up.

"We want to read the genes of the virus that killed 30 million people," he told BBC News Online, drawing a comparison with the work of the human genome project.

"If we can find a well-preserved body from someone who died of the Spanish flu in 1918, we could answer all sorts of questions," he added.

They do not expect to find the virus intact, he said, but it should have left its "footprint" in the patients' lungs.

This could help scientists understand the genetic nature of the virus and explain why it was so contagious.

Arctic quest

The quest is the latest in a worldwide search for clues to the 1918 flu pandemic.

Spanish Flu

Killed 20-40 million people in 1918 and 1919

Unlike most strains of flu, it struck healthy young people

It is still unclear why so many people died

The flu virus contains eight separate pieces of genetic material, called gene segments

An expedition to the Norwegian island of Spitzbergen two years ago, to extract virus from the bodies of coal miners, was only partially successful.

Although the six men were buried in permafrost - soil that stays frozen all year round - their bodies were not as well preserved as had been hoped.

Professor Oxford thinks the answer could lie closer to home. The team is now trying to trace living relatives of those buried in London to get permission to exhume the bodies.

They also need authorisation from the Home Office and cemetery owners.