Page 128 - JSOM Fall 2022

An Ongoing Series

Smallpox as a Bioagent
A Refresher and Update for the SOF Provider

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S. Jawad Zafar, MD ; Akira A. Shishido, MD *
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ABSTRACT
Smallpox plagued humans for millennia until its eradication in Smallpox was used as a biological weapon as early as the 14th
1980 following a successful global campaign led by the World century when Tartar forces catapulted corpses of smallpox
Health Organization (WHO). It is the first known biological victims into encircled towns to weaken defending troops.
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weapon to be used in war and has been weaponized in the More recently, Russian defector Kenneth Alibek provided
past by the former Soviet Union. To date, smallpox remains public testimony that the former Soviet Union had developed
a Category A Bioagent and is assessed to be a relevant threat a sophisticated bioweapons program and had weaponized
to US military personnel. Given that the last natural case of smallpox. Smallpox makes for an attractive bioagent due
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smallpox occurred more than 40 years ago, a high level of sus­ its high case­fatality rate, transmissibility, and lack of immu­
picion along with a substantial understanding of the disease nity in the general population. To date, smallpox remains a
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process are required to recognize potential future cases. While Category A Bioagent and is assessed to be a relevant threat
available countermeasures are limited, several new agents have to US military personnel. 9,10 This review serves as a refresher
recently become available for the prevention and treatment of and update for the clinical disease, epidemiology, and man­
smallpox and have been added to the strategic national stock­ agement of smallpox, to include the newly FDA­approved
pile. This review serves as a refresher and update for the clini­ countermeasures.
cal disease, to include its epidemiology and management with
updated FDA­approved countermeasures.
Context With US Military
Keywords: military medicine; bioterrorism; smallpox; bioagents; After the US military ceased smallpox vaccination in 1990,
bioweapon the anthrax attacks following September 11, 2001, renewed
public concern for bioterrorism agents. In response, the
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Centers for Disease Control and Prevention (CDC) revised
recommendations for smallpox vaccination, and in 2002 the
Introduction
US military reinstituted smallpox vaccination. 11,12 Since that
Smallpox is an ancient disease caused by the double­stranded time, more than 1 million Servicemembers have received at
DNA Orthopoxvirus Variola. Smallpox is suspected of killing least one dose of smallpox vaccine. Department of Defense
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more humans than any other single cause of death over the (DoD) policies have narrowed the practice of vaccination in
course of human history and caused an estimated 300 mil­ scope to where, as of this article’s writing in 2021, required
lion deaths in the 20th century alone. Evidence of smallpox vaccination against smallpox has been suspended except for
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infection can be traced as early as the 3rd century BCE from personnel deploying to the Korean peninsula and personnel
the pustules on the face of the mummy of Pharaoh Ramses supporting chemical, biology, radiological, nuclear, and ex­
V. 1,4,5 The first description of smallpox appeared in a Chinese plosives (CBRNE) operations. 10,14 With the recent withdrawal
text in the 4th century BCE. During the Revolutionary War, from Afghanistan and advent of near­peer threats with di­
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smallpox decimated the Continental Army so severely that rected energy weapons, the military medical community will
George Washington executed the first mass military inocula­ likely see a repivot in preparedness with attention focused
tion against smallpox in America. In 1796, Edward Jenner on countermeasures against alternative forms of weaponry.
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discovered a vaccine that protected against acquiring the dis­ While the Russian Federation is the only country outside the
ease. More recently, the World Health Organization (WHO) US openly known to possess live smallpox, it is likely that
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led a global smallpox eradication campaign and successfully other states as well as terrorist and paramilitary organiza­
eradicated the disease from nature in 1980. However, due to tions possess it as well. 8,16–19 The testimony of Russian defec­
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its development as a biological weapon, smallpox remains an tor Kenneth Alibek effectively confirms the weaponization of
active threat to US military personnel. 5,7,8 smallpox by a near­peer state. 7
*Correspondence to akira.shishido@vcuhealth.org
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1 Dr S. Jawad Zafar and Dr Akira A. Shisido are both affiliated with the Department of Medicine, Division of Infectious Diseases, University of
Maryland Medical Center, Baltimore, MD.
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