Tuesday, March 21, 2017

A Historical Inquiry into Viral Bioweapons

In his book Biovalence: Preventing Biological Terror and Crime, author Barry Kellman talk about the various ways in which biological weaponry have been used, and could be used, to inflict mass causalities.  While this is certainty a good read, he mentions in one section how soviet scientists spliced Venezuelan equine encephalomyelitis (VEE) genes into smallpox to create a “chimera” virus that would be resistant to vaccines and anti-viral treatments.  I was curious what genes were spliced, and how these could possibly confer resistance.

VEEV virus is a member of the togaviridae viral family, and is positive sense single stranded RNA virus, while smallpox is a member of the poxviridae family and is a double stranded DNA virus.  On a practical level one has to admire how splicing these genomes together in the cold war era would have been quite a technological feat. Why did they do it then? What qualities did VEEV have that smallpox could have benefited from to make a deadlier bioweapon?

My initial theory was that VEE genes when combined with the variola (virus that causes smallpox syndrome) genome, would result in a hybrid virus capable of the neurological symptoms of VEE, such as headache and coma, and the conventional smallpox symptoms in a chimera virus they named VeePox.  I though this was unusual, as smallpox already seemed symptomatic enough, and the source does not elaborate on why VEE was chosen specifically. There are numerous sources that quote the soviet scientist Ken Alibek, who defected to the U.S. and gave us the intel on what the soviets were doing, but I have been unable to find what specific genes were spliced.

However, after investigation it was not the symptoms of VEEV that made it appealing as a potential bioweapon, but rather the expense in producing a biological weapon.  The VEE virus is cheap to produce on a large scale, and much much more stable than the smallpox virus.  Without knowing more about the specific genes that were spliced, I would argue that it was the practical aspects of VEEV that made it a good candidate for recombination.

A person possibly infected with VeePox
Image credit

-Cynthia Taylor

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