University of Texas researchers see influenza as a greater bioweapons threat than smallpox.
The Texas researchers wrote in the Journal of the Royal Society of Medicine that scientists are close to completing the blueprint of the 1918 Spanish Flu (search) that killed 20-40 million people around the world, including half a million in the United States. That blueprint, they said, could provide the recipe for terrorists looking for a deadly weapon.
The sequencing of the 1918 Spanish Flu DNA has been underway for quite some time as this 2001 PNAS paper demonstrates. Once it is complete the sequence will be available for use by any group capable of building a virus from scratch or by any group that can modify an existing influenza virus strain to put in the genetic variations that caused the level of virulence that was characteristic of the 1918 strain.
The complete sequence of the 1918 flu will be known within 2 years. Madjid says that it will become increasingly easier to build the 1918 virus from the sequence information.
Dr Madjid told BBC News Online: "Using influenza as a bioweapon is a probability.
"It's just a matter of technology. If it's difficult now, it will be easier in six months and much easier in a year's time."
He is right about the increasing ease of creating such a virus. This is more generally true of building almost any kind of weapon you can imagine. The more technology advances the easier it becomes to make things.
Here is the Pub Med entry for the paper by Mohammad Madjid MD, Scott Lillibridge MD, Parsa Mirhaji MD, and Ward Casscells MD on Influenza as a bioweapon. From the Royal Society of Medicine Press Release on this paper.
Many bioterror warnings have focused on diseases like smallpox, but flu has very different implications for public health. Influenza is far more easily available, and common enough that a cluster of cases would not cause alarm at first. Once an epidemic has begun, it is more difficult to immunize against, as the incubation period is short. The virus is very difficult to eradicate since birds, rats and pigs all carry flu.
A third difference is that the incubation period for influenza is short (1–4 days) versus 10–14 days for smallpox. Immunization after exposure to influenza is therefore not protective, and even the neuraminidase inhibitors such as oseltamivir must be administered before symptoms develop or within the first 48 hours after their appearance. Fourth, influenza is harder to eradicate, because of avian, murine, and swine reservoirs. Fifth, influenza outside of pandemics, has lower case-fatality (2.5% versus 25%, though the newly recognized triggering of cardiovascular events suggests that the true mortality may be much higher in ill or elderly persons). Finally, influenza poses a greater threat to world leaders than does smallpox, because they are older and prone to influenza and its cardiovascular complications, have some residual immunity to smallpox (whereas unvaccinated youth have none), and are often in public places.
As I've previously argued, we need facilities that are capable of being operated in a crisis mode to very rapidly sequence and make a vaccine for a new killer strain of influenza. That strain might arise naturally (this seems inevitable in fact) or it could be made by terrorists. But eventually we are going to be faced with it. The development of DNA vaccine technology for influenza has the potential of enabling the manufacture of much greater quantities of vaccine more quickly and cheaply than conventional vaccine manufacturing approaches. Therefore DNA vaccine development for more influenza strains should be a priority as a useful learning experience.
|Share |||Randall Parker, 2003 July 11 04:33 PM Dangers Biowarfare|