DNA vaccine may stem spread.

• Position: Avian Flu

Researchers scrambling to combat a virulent form of bird flu that could mutate into a strain easily spread among humans should consider developing vaccines based on DNA, suggest British biochemical engineers. DNA vaccines, they say, can be produced more rapidly than conventional ones and possibly could save thousands of lives if a global influenza outbreak occurs.

A DNA-based vaccine could be a potent weapon against this emerging threat, particularly if enough conventional vaccine is not available, according to Peter Dunnill and his colleagues at University College London. However, they caution that any DNA vaccine should be used only as needed to slow the spread of the disease because the technique largely is untested in humans.

The avian virus H5N1 has spread among birds throughout Southeast Asia while also being detected in Eastern Europe. (A different, milder strain was found circulating in Canada as well.) The virus has killed over 60 people in Asia since 2003 and forced the slaughter of millions of birds. There have been no confirmed cases of human-to-human transmission, but that could change as the virus continues to mutate.

If that occurs, current production facilities are unlikely to meet global demands for conventional vaccines in time to avert a pandemic, Dunnill warns. Yet, it might be possible to produce a DNA vaccine quickly by adapting the manufacturing processes of selected biopharmaceutical and antibiotic plants in countries such as the U.S., China, and India.

"A DNA vaccine is not a panacea. However, it could be useful if the...