The technique to create the first synthetic polio virus was recently revealed, and experts say that it can also be used to synthesize Ebola and other viruses. This has elevated concerns over the potential for bio-terrorism, among other worries.

Researchers at Stony Brook University in New York bought bits of the polio virus' sequence from different companies that make pieces of DNA to order. The team assembled the genome from these pieces and added it to cellular components that mimic a human cell, resulting in perfectly formed viral particles.

While not quite as simple as that summary, the technique is, scientifically speaking, still quite simple: anyone with knowledge of a virus sequence, some training and some common tools can recreate the polio virus in a test tube. While this will not alter the World Health Organization's effort to eradicate polio worldwide, it does mean that, even when worldwide vaccines for polio are complete, vaccines for the disease will have to be maintained.

Far more disturbing is the potential for replicating other deadly viruses. Synthesizing Ebola is more difficult than polio, as it requires viral proteins as well as the genome, but scientists have already used "reverse genetics" to overcome the obstacle: the knowledge is in place to recreate the viral proteins. There are no hurdles left, in terms of knowledge, to prevent replication of the Ebola virus. The same is true of 1918 influenza virus that took 40 million lives - once all of the viruses' gene sequences have been determined in about two years, virtually anyone could use reverse genetics to synthesize the virus.

Smallpox would be more difficult to recreate, as its sequence, at around 185,000 base pairs, is much longer than the influenza or Ebola viruses.

For anyone willing to invest the time, however, it too is possible.

Currently, those companies the make DNA molecules do not monitor what their clients - from all corners of the globe -- are ordering. Monitoring and restricting access to pieces of DNA, however, would not necessarily stop bioterrorists from synthesizing certain deadly viruses; anyone intent on recreating such a virus could take a closely related viral cousin and change the key portions of its sequence to those of the deadly virus. If that is not troubling enough, there is also great potential to tweak these viruses to create even deadlier strains.

New Scientist July 17, 2002