American Scientist

Pox Americana: The Great Smallpox Epidemic of 1775–82. Elizabeth A. Fenn. xiv + 370 pp. Hill and Wang, 2001. $25.

Scourge: The Once and Future Threat of Smallpox. Jonathan B. Tucker. x + 291 pp. Atlantic Monthly Press, 2001. $26.

By now most of us realize that humanity is leaving an ugly footprint on the rest of the living world. But we are less aware of how human history, in turn, has been shaped by our interactions with other species. Pox Americana and Scourge invite the reader to focus on the long and troubled history of hostile relations between two species: Homo sapiens and Variola major. At first glance, this matchup seems grotesquely one-sided: The smallpox genome is 10,000 times smaller than that of human beings and encodes but a handful of proteins (in contrast to the 30,000 to 100,000 proteins encoded by human DNA). But the small size and apparent simplicity of the smallpox virus belie its evolutionary sophistication.

Like most viruses, Variola major has evolved into the ideal traveler. A virus, knowing exactly what it will find when it arrives at its host destination, carries only what it needs in order to take over the host's biochemical machinery, thus ensuring its own survival and replication. (Think of packing for a trip to an exotic destination armed only with a good map, a credit card, a set of skeleton keys and the address of the best restaurant in town, and you begin to get the picture.)

Furthermore, the most successful viruses have evolved to take advantage, inexorably, of the ingrained foibles of their hosts. Thus, HIV relies on the irrepressible human desire for sex, and influenza on our inability to cover our mouths and then wash our hands every time we sneeze. The smallpox virus, too, has come to rely on some fairly dependable and sometimes contradictory features of human behavior. Over the past 10,000 years, the number and density of human beings on the planet has risen dramatically. The pleasure we derive from being with others, along with our wanderlust and desire to explore, sets the stage nicely for smallpox. This virus, after all, cannot live on its own for very long. It depends on a steady supply of susceptible individuals living in sufficiently close contact to enable it to jump from one host to another. Unchecked, smallpox will move through an entire population. Those it does not kill acquire immunity and cannot be reinfected. If the virus is to survive, it must reach a new population of unexposed hosts. European colonial ambitions, from the 15th century onward, could not have come in more handy in this regard. An entire continent lay over the horizon, waiting to be infected.

These two books address the interaction between human beings and smallpox from two very different perspectives. In Pox Americana, Elizabeth Fenn focuses on the profound, and, at least to me, unknown role played by smallpox in shaping the history of the American continent from 1775 to 1782. She brings the historian's craft to bear on the study of the epidemic raging at that time, and her account is both enthralling and meticulous.

Pox Americana is all the more compelling because Fenn eschews sweeping generalizations and grand simplifications. Instead, she creates a pointillist portrait in which individual episodes, examined in detail, come together to form a sharp picture of the devastation wrought by this disease. Relying on letters, firsthand accounts and burial registers, Fenn not only evokes the fears and superstitions aroused by smallpox but also captures the ingenuity and resourcefulness of those battling the disease, with quarantine and variolation (an early version of vaccination).

The book also avoids the sort of intellectual bravado that would reduce all of the events of the Revolutionary War to the waxing and waning of smallpox. Instead, the reality of the disease is woven into the fabric of historical reconstruction, and the results are both poignant and illuminating. For instance, we come to understand the gamble that George Washington had to take in choosing to have his troops inoculated in 1777, when he knew full well that some would die, many would be temporarily incapacitated, and a new epidemic cycle could be unleashed. We learn just how the insatiable demand for beaver pelts, pressed into hat lining for European dandies, spawned the expansion of the Hudson Bay Company, resulting in the devastating westward spread of smallpox. We witness the tragedy of the Ethiopian Regiment, composed entirely of slaves fighting on the side of the British crown (having been offered their freedom by Lord Dunsmore, the governor of Virginia), being completely wiped out by smallpox while awaiting action near Portsmouth, Virginia.

Finally, Pox Americana makes a compelling case for one of the earliest systematic uses of biological warfare, documenting the extent to which the British army used infected civilians and soldiers—particularly black soldiers serving the loyalist cause in exchange for promises of freedom—to spread smallpox among the vulnerable American citizenry. (Small irony: I write this review in Amherst, Massachusetts, a town named after the British commander who approved the distribution of smallpox-infected blankets to the Ottawa Indians then besieging Fort Pitt.)

Each of these episodes is mesmerizing in its own right; taken together, the effect is profound. Precisely because the author is a historian, she has captured the fundamental reality of all human epidemics: It's not just the biology, stupid. Instead, it is the interactions between biology and socioeconomic variables (class, privilege, nutrition, crowding, access to medical care) and between biology and historical events (wars, migrations) that determine the real dynamics of infectious disease.

Jonathan Tucker's Scourge, an altogether different sort of book, recounts the history of smallpox and our attempts to control it and, more recently, misuse it. The eradication of smallpox is one of the great, unambiguous triumphs of modern science and a vivid testament to what happens when the cool, streamlined efficiency of the viral lifestyle meets human ingenuity and will. In my lifetime, smallpox has gone from being a disease that killed more than two million people a year (in 1965) to being a disease that gave Ali Maow Maalin, a 23-year-old Somali who was the last known individual infected through natural transmission, a headache and a rash from which he soon recovered (in 1977). This victory over disease was made possible by the concerted efforts of tens of thousands of individuals, from university researchers to inoculation technicians deep in the Ogaden Desert.

The eradication of smallpox also required a level of cooperation between nations that stands in stark contrast to much of the arrogance and shortsightedness that characterized the Cold War. Tucker, a political scientist specializing in biological and chemical warfare, does a good job of sketching the personalities of some of the major players in this drama, as well as the complex motives and sometimes absurd petty politics that threatened to derail the effort. Eventually, however, sweeping statements and oversimplifications creep into Tucker's prose, and the book seems at times overdramatic.

The real strength of Scourge lies in its recounting of the very recent history of smallpox. Tucker has served the federal government in various capacities and clearly has access to people and information most of us do not see. As a result, this is an insider's account of the potential uses of smallpox both as a state-sanctioned weapon and a tool for terrorism. To say the least, this material is disturbing. Tucker describes in detail the extensive bioweapons program that was apparently ongoing in the Soviet Union until quite recently, based largely on the information provided by defector Ken Alibek, who was a senior scientist in the Soviet effort. (It is important to note that Alibek is the sole source of information for many of the assertions about the Soviet biowarfare program, and the book's frustratingly organized references make independent verification difficult).

Soviet military planners saw smallpox as a good starting point for a biological weapon and as a necessary counterweight to the growing technological advantage enjoyed by the West at the peak of the Cold War buildup. The logic of this is chilling, suggesting as it does that a bit of black biology could equalize the playing field. The Soviet objective was the creation of a weaponized strain of smallpox that could readily be loaded onto warheads and various types of ordnance. In addition, the program aimed to modify naturally occurring strains of Variola major to increase the transmissibility and lethality of the infection. It may also have intended to create new chimeras—viruses that would combine the lethality of smallpox with the most disagreeable properties of a number of other pathogenic viruses. And, in a note that underscores the lunacy and paranoia that occasionally afflicts weapons designers, Tucker reveals that Soviet scientists were investigating chemical additives that would protect the smallpox weapons from the damaging effects of radioactive fallout in the event of a nuclear attack.

While all this was going on, the United States was presumably abiding faithfully by the terms of a 1972 treaty banning research on offensive biological weapons, but it was also engaged in a disinformation campaign meant to convince the Soviets that American bioweapons research was indeed taking place. Given the climate of the time, it is unclear what the United States expected the Soviet reaction to this (dis)information would be.

A debate now rages about the fate of the known remaining stocks of Variola major, held in laboratories in Russia and the United States. The destructionists believe that our victory against smallpox will only be complete when all stocks are destroyed, thus eliminating the possibility of accidental or intentional release. The retentionists argue that any further research on smallpox, including the development of potential antiviral drugs that would stop the spread of any smallpox outbreak, requires the existence of small stocks of Variola major held under tight security. Tucker chronicles this debate with considerable care, and in the process underscores the transformation of this issue from a scientific to a political debate. The fate of Variola stocks is in effect a discussion about military preparedness and future weapons development, about the credibility of snippets of intelligence that suggest that other countries or organizations may have smallpox at their disposal, and about high-level Washington internal politics. Curiously, we are obsessed with the high-technology breakthroughs that would be required to deliver vast amounts of weaponized smallpox to urban centers, and we appear to gain some measure of comfort from the knowledge that few countries have the infrastructure to achieve such breakthroughs. The events of the past several months remind us of just how little technology is required to wreak havoc. As these two books underscore, smallpox, carried willingly or unsuspectingly by a few infected individuals, could unleash a scenario we are not yet ready to deal with.

We will eventually have to decide whether the eradication of smallpox will stand as one of the truly great achievements of our species or will turn out to have provided the breeding ground for a crushing defeat. The disappearance of smallpox as an inexorable fact of the human condition has led to the disappearance of acquired immunity and has made the potential risks of immunization greater than the potential benefits. But it has also made the entire planet virgin territory for a new smallpox epidemic, likely to occur only as a result of willful or accidental release by human agency. As these books make clear, what should have been a clear outcome—human beings 1, smallpox 0—has been muddied by the darker side of human creativity. We hope for the best but should likely plan for the worst.