Monday, November 01, 2004

Smallpox secrets partially unveiled

The New York Jewish Times reports that a NIH-funded study, published in PNAS last month, unveiled some smallpox secrets using microarrays. As you may know, smallpox is a potentially deadly virus who have been eradicated thanks to an extensive vaccination campaign. The only problem is that my generation (young adults) wasn't vaccinated and authorities fear that smallpox could be intentionally released by terrorists organization as a biological weapon (it would cause more fear than harm, but anyway). The only time it has successfully been used as a weapon of War was in 1754-67, by British forces who gave infected blankets to native Americans; some tribes lost 50% of their population.

The study used microarrays (the cDNA kind) to characterize changes in PBMCs (Peripheral blood mononuclear cells - T & B cells, macrophages, monocytes, etc) from 22 sinomolgus macaques (a study published in the same issue of PNAS shows that they can be infected with smallpox and develop a disease similar to human smallpox - previously, no animal model was available). From the abstract (will have access to the full text tomorrow) :

"Of particular interest were features that appear to represent an IFN response, cell proliferation, immunoglobulin gene expression, viral dose-dependent gene expression patterns, and viral modulation of the host immune response. The virtual absence of a tumor necrosis factor alpha/NF-kappaB-activated transcriptional program in the face of an overwhelming systemic infection suggests that variola gene products may ablate this response. These results provide a detailed picture of the host transcriptional response during smallpox infection, and may help guide the development of diagnostic, therapeutic, and prophylactic strategies."

Understanding the virus, even if its extinct, is good in case we have to face it again. According to :

"Which countries have smallpox stockpiles?
Officially, smallpox remains in only two places in the world: the CDC in Atlanta, Georgia, and a repository in Russia. In 1971, the Soviet Union tested a biological weapon containing smallpox; it killed three people and had to be contained by an extensive vaccination campaign. Recent reports indicate that in the early 1980s, Russia grew large quantities of smallpox and successfully adapted it for use in bombs and missiles."

"Are the Russian smallpox stockpiles safe?
Since many laboratories in Russia are now financially strapped and are downsizing, the United States is worried that underpaid or unemployed Russian scientists and researchers might sell, or have sold, bioweapons expertise or equipment to terrorists or rogue states."

But don't panic just yet : the virus is difficult to produce, cultivate, almost impossible to dissipate on a large scale (stay infectious for ~24 hours, less under the sun). Vaccination (stockpiled) is available, symptoms are difficult to miss (a BIG rash).. etc. It would be effective the way anthrax was : create a massive paranoia, paralyze the targeted country, and cause very few deaths. A terrorist weapon; ineffective, but with a big scare factor.

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