Expert Ponders Whether Remaining Stockpiles of Smallpox Virus Should be Destroyed

Raymond S. Weinstein, a clinical associate professor of medicine at Georgetown University School of Medicine in Washington, D.C. and a research professor at George Mason University in Manassas, Va., ponders the question of whether the remaining stockpile of variola -- which is currently in the United States at the Centers for Disease Control and Prevention (CDC) and in Russia at the State Research Centre of Virology and Biotechnology -- should be destroyed.

In a policy review paper in Emerging Infectious Diseases, Weinstein points to the fact that this year, the World Health Organization (WHO) will recommend the fate of existing smallpox stockpiles, but notes that circumstances have changed since the complete destruction of these cultures was first proposed. Weinstein says that recent studies suggest that variola and its experimental surrogate, vaccinia, have a remarkable ability to modify the human immune response through complex mechanisms that scientists are only just beginning to unravel. Further study that might require intact virus is essential. Moreover, Weinstein says that modern science now has the capability to recreate smallpox or a smallpox-like organism in the laboratory in addition to the risk of nature re-creating it as it did once before. These factors strongly suggest that relegating smallpox to the autoclave of extinction would be ill advised.

Weinstein writes, "Today's science is capable, through genetic manipulation, of re-creating a highly virulent smallpox-like virus from a closely related poxvirus or even from scratch. But perhaps what we should fear even more is nature creating it for us, as it so efficiently did once before from the still-existent progenitors of variola. The possibility is certainly not unthinkable that nature could once again fashion smallpox from a near relative poxvirus or even create a new, smallpox-like human pathogen from a clinically similar but more genetically divergent zoonotic poxvirus, such as monkeypox. Several recent reviews have reported an increasing prevalence of human monkeypox since smallpox eradication and the cessation of vaccinia vaccination. The possible re-creation of smallpox by either natural or modern laboratory means would render moot any argument regarding the destruction of remaining stockpiles of smallpox virus in the mistaken belief that it would be for the benefit and protection of mankind."

Reference: Weinstein RS. Should remaining stockpiles of smallpox virus (variola) be destroyed? Emerg Infect Dis. Vol. 17, No. 4. April 2011.