BioEd Online

As part of the effort to thwart a global flu pandemic, US scientists have announced a scheme to determine the genetic sequence of many thousands of strains of influenza.

Researchers already glean invaluable information about the flu virus from its genetic material, for example, what makes one strain more virulent than another. But such data have largely been based on scraps of genetic sequence from only a few strains.

Those behind the new project, led by a group of scientific institutions including the US National Institute of Allergy and Infectious Diseases (NIAID), aim to log the complete genetic sequence of many thousands of influenza strains that strike both people and birds. Birds are thought to be the breeding ground for vicious human flu strains that periodically sweep the globe, killing millions.

The announcement, made on 15 November, comes at a time when fears about the next flu pandemic are running high. Specialists fear that the avian influenza decimating bird flocks across Asia may gain the ability to spread easily between people. At the same time, the fragility of vaccine supplies has been thrown into the spotlight after a manufacturing hiccup wrote off half the US supply in October.

Strain training

With influenza genomes deposited in a database, the organizers hope to spur scientists in their efforts to stave off the next pandemic. They might, for example, survey and compare the virus strains circulating in poultry to see how they are changing. This might alert them to an imminent epidemic and may help them to select a strain to target with a vaccine.

The information might also piece together a more accurate picture of what makes one strain more lethal than another, or more virulent in a particular population. "We really want a database of lots of different viruses," says Maria Giovanni, project leader at the NIAID, which will invest $1 million to $2 million annually in the project.

Giovanni says that the group has already set up a production line for growing different strains of the virus, isolating their genetic material and sequencing them one by one. Researchers hope to work their way through perhaps 500-1,000 strains a year, each of them more than 13,000 genetic letters long.

The next step, Giovanni says, is to consult with scientists about which strains they would like to begin with and how to prioritize them. Robert Webster of St Jude Children's Research Hospital in Memphis, Tennessee, for example, is involved in the sequencing project and has a repository of over 12,000 bird flu strains collected over 27 years.