FEATURE ARTICLE
The Growing Threat of Biological Weapons
The terrorist threat is very real, and it's about to get worse. Scientists should concern themselves before it's too late
Steven Block
For half a century, America has participated with the world's nuclear
powers in an uneasy standoff of mutually assured destruction.
Despite the seemingly relentless proliferation of nuclear arms,
there's reason to hope that some version of the current stalemate
will continue to hold. Against this backdrop, terrorist factions and
"nations of concern" (the current government euphemism for
rogue states) have sought ways to leverage their chances. In the
jargon of the day, they seek a means to wage "asymmetric
warfare" against a more powerful, nuclear-capable adversary.
Asymmetric warfare concentrates on the use of unconventional (and
affordable) weapons and tactics, ranging from traditional guerrilla
fighting to the deployment of new weapons of mass destruction.
Ironically, the supremacy in conventional weaponry established by
the U.S.—and demonstrated to lethal effect during the 1991
Gulf War—has made asymmetric warfare all the more attractive.
Figuring prominently in the arsenal of asymmetric warfare are both
biological and chemical weapons. Although it may be something of a
misnomer to label most current forms of these agents as
"weapons of mass destruction," their power is nevertheless
considerable. Worse still, it is now increasing, and these weapons
are emerging as a serious threat to peace in the 21st century. Here
I explore the historical development and use of biological weapons,
as well as some recent trends in their evolution and the prospects
for containing their proliferation.
The Plague and Anthrax
Biological warfare is not a new phenomenon. The ancient Romans, and
others before them, threw carrion into wells to poison their
adversaries' drinking water. In the 14th century the Tatars
catapulted the bodies of bubonic-plague victims over the city walls
of Kaffa, a Black Sea port that served as a gateway to the Silk Road
trade route. People inside the city soon came down with the disease,
suggesting that the maneuver may have worked—but the tactic
may have exceeded the Tatars' operational goals. Some of the city's
inhabitants escaped in sailing ships, which happened to be infested
with rats, carrying fleas infected with the causative agent of
plague, the bacterium Yersinia pestis. The escaping ships
entered various Italian ports that subsequently served as foci for
the spread of the disease. Over the next three years, the bubonic
plague—the Black Death—raged northward, wiping out
nearly a third of Western Europe.
It was not until the 19th century that the microbial basis for
infectious disease was understood. One of the first illnesses to be
explained by the new germ theory was anthrax, an infectious disease
common to sheep and cattle. Indeed, the primary architects of the
germ theory??Robert Koch, Louis Pasteur and Joseph Lister??were
instrumental in describing anthrax and its containment. Koch was the
first to isolate and describe the anthrax bacterium (Bacillus
anthracis). Pasteur developed the first animal vaccine against
anthrax, which, together with Lister's ideas about antiseptic
precautions, helped turn the tide against outbreaks of the disease.
Anthrax is only weakly communicable in humans and rarely causes
disease, unless the bacterium comes into contact with the
bloodstream through a wound (causing cutaneous anthrax) or is
ingested in contaminated meat (resulting in intestinal anthrax).
However, Bacillus anthracis has the ability to form
resistant spores, which can remain viable for over a hundred years
if kept desiccated and out of direct sunlight. Breathing in
significant numbers of spores (typically estimated at about 10,000)
can lead to inhalation anthrax in humans, which was historically
called "woolsorter's disease" because spores were
prevalent in the contaminated wool of sheep in 19th-century England.
Inhalation anthrax is a very deadly disease in humans. Unless
treated with large doses of a penicillin-type antibiotic within the
first day or so of exposure it has a mortality rate in excess of 80
percent. This is to be contrasted with smallpox, which has a
mortality rate of "only" around 30 percent. Only some
filoviruses, such as Ebola, which cause hemorrhagic fevers, have
comparable rates of mortality.
All of this suggests why Bacillus anthracis became the
agent of choice for most biological warfare programs. Consider the
properties of anthrax. It is convenient: Variants of the anthrax
bacterium can be isolated worldwide (although not all possess equal
virulence), and great quantities of spores can be readily prepared
from liquid cultures. It is robust: Once desiccated and stabilized,
hardy spores have a long shelf life and are well suited to
weaponization in a device that can deliver a widespread aerosol. It
is self-terminating: Airborne spores remain infectious until they
fall to the ground, where most become inactivated by sunlight. It is
effective: After inhalation the spores produce disease with a high
mortality and morbidity. It can be contained: Anthrax is not very
communicable, thereby reducing the risk that it will spread beyond
the intended target. Moreover, a well-established vaccine exists
that can prevent the onset of the disease, allowing it to be used
safely by the aggressor. This is a two-edged sword, of course, since
the vaccine may be available to the target population as well. For
this reason alone, anthrax doesn't quite qualify as the perfect bioweapon.
There are certain other drawbacks to anthrax as a weapon. The number
of spores that must be delivered to the lungs to produce the disease
is quite high compared with some other infectious agents??it has
been estimated that certain viruses and rickettsiae may communicate
disease with just a single particle. Finally, for conventional
anthrax, antibiotic treatment can be effective if administered
quickly. Even so, of all the natural biowarfare agents, anthrax
traditionally ranks near the top of everyone's short list.
The World Wars
The First World War saw one of the first attempts to use anthrax
during warfare, directed??ineffectively??against animal populations.
Instead, WWI became infamous for its introduction of poisonous
mustard gas, which was used effectively against humans. (By odd
coincidence, WWI also overlapped with a deadly outbreak of
influenza, the Great Pandemic of 1918, which eventually killed more
people than the Great War itself.) International revulsion at the
horrors of WWI led to the signing of the Geneva Protocol of 1925,
which went into force on February 8, 1928, with 29 participating
nations, including the U.S. The treaty contained "A Protocol
for the Prohibition of the Use in War of Asphyxiating gas, and of
Bacteriological Methods of Warfare."
Although the Geneva Protocol didn't expressly forbid the production
and development of biological weaponry, it did ban all use during
war. Disappointingly, neither the U.S. nor Japan ratified the treaty
before the advent of World War II, when anthrax and other bioweapons
were secretly being developed by both countries??as well as by
Germany, the U.S.S.R. and Great Britain. The Japanese and British
bioweapons programs were particularly extensive, but no documented
use of agents ever occurred during combat. This may have been due to
residual respect for the 1925 treaty or, what seems more likely,
from the relative immaturity and associated imperfections of
bioweapons technology.
There were some notorious instances of biological warfare during
this period, however. The Japanese Military Unit 731 at Ping Fan,
Manchuria, experimented extensively with bioweapons, killing
thousands of prisoners of war with anthrax, cholera, plague,
dysentery and other infectious agents. They also released plague on
the Chinese civilian population of Chekiang Province on several
occasions by dropping from airplanes laboratory-grown fleas fed on
infected rats. The Soviets may have deliberately infected German
Panzer troops with tularemia during the Battle of Stalingrad in
1942, by far the costliest battle of WWII, but the ensuing outbreak
soon spread to both sides and resulted in more than 100,000 cases of
the disease.
Unlike the years following WWI, the post-WWII period heard little
public debate concerning the need to limit bioweapons??perhaps owing
to the global preoccupation with nuclear arms that began in 1945.
With the advent of the Cold War, the U.S. biowarfare program (begun
in 1942 and aided by postwar intelligence from the Japanese) went
into overdrive. Over the course of the next 25 years, the U.S. would
quietly develop, test and weaponize at least 10 different biowarfare
agents, including bacteria, viruses and microbe-derived toxins. The
U.S. not only experimented with human disease, but also targeted
economically vital agriculture with fungal weapons such as wheat
rust and rice blast. The Soviets had a program that was every bit a
match for the American one, but concentrated on a different subset
of diseases. Both countries stockpiled plenty of anthrax.
A good deal of effort on both sides went into attacking the problem
of weaponization. Biowarfare agents may be deadly, but they are also
labile and difficult to deliver to the intended target. It took
years of experimentation before the U.S. and Soviet programs
eventually succeeded in developing effective means of stabilization
and distribution??in the form of explosive bomblets or aerosol-spray
weapons that could be delivered by aircraft or ballistic missiles.
Today, the operating principles of such delivery devices are among
the most closely held national secrets. This is entirely
appropriate, given the relative ease with which most other aspects
of the bioweapons problem are tackled.
Modern-Day Transgressions
On November 25, 1969, under President Nixon, the U.S. announced that
it would unilaterally and unconditionally renounce all biological
weapons. Following executive order, the U.S. program was summarily
terminated, and the Department of Defense was instructed to destroy
all remaining stockpiles of weapons based on biological agents. This
order was extended the following year to cover toxin weapons,
including biologically produced toxins. The existing American
stockpiles of biological weapons were destroyed between May 1971 and
May 1972.
These welcome developments paved the way for the landmark
international treaty of April 10, 1972, the Biological and Toxin
Weapons Convention (or BWC)??which has now been signed by 160
nations and ratified by 143. Among the countries that have signed
and ratified the treaty are the U.S., Great Britain, China, the
Russian Federation, Iraq, Iran, Libya and North Korea??some of which
figure prominently in reports of actual or suspected bioweapons
programs. Eighteen nations signed the treaty but subsequently failed
to ratify it??including Egypt, Syria and Somalia??and 34 nations
haven't even signed it, including Israel.
The BWC, which went into force in March 1975, took ambitious steps
to ban both biological and chemical weapons, including their
development, production, procurement or stockpiling for any hostile
purpose or use in armed conflict. Unfortunately, the BWC
incorporated no provisions to investigate or follow up on suspicious
activities. It lacked "teeth."
Perhaps the greatest BWC transgression of all occurred between 1972
and 1992, when a truly massive bioweapons effort was under way in
the Soviet Union. Despite endorsing the BWC Treaty, the Soviet Union
carried out ultra-secret bioweapons work right up until it collapsed
in 1990. Some experts contend that a low, but significant, level of
research still exists today. Revelations of the staggering scope of
the Soviet program have only recently come to light, after the
much-publicized defection of Ken Alibek??formerly Colonel Kanatjan
Alibekov??the Deputy Director of Biopreparat, the Soviet
state "pharmaceutical" agency charged with carrying out
bioweapons research.
Alibek has called Biopreparat "the darkest conspiracy of the
cold war" and tells a chilling tale. During the heyday of the
Soviet program, Alibek supervised as many as 32,000 people (out of
60,000 in the program) at nearly 40 facilities spread throughout the
Soviet Union??effectively a "toxic archipelago." Here the
Soviets worked not only on perfecting "conventional"
biological weapons based on anthrax, glanders and plague, but also
on weaponizing deadly (and highly contagious) viruses such as
smallpox, Marburg and Ebola. In contrast to the American bioweapons
effort, the Soviets considered the best bioweapons agents to be
those for which there was no prevention and no cure.
It was during Biopreparat's heyday, in 1979, that the
"Sverdlovsk incident" occurred. In April and May of that
year, about 100 people and uncounted livestock suddenly died of
anthrax in Sverdlovsk (now Yekaterinburg), a city of 1.2 million
people. All the victims were located within a narrow band directly
downwind of a secure microbiological facility run by the military.
The Soviet authorities blamed the deaths on contaminated meat
(intestinal anthrax), whereas U.S. agencies attributed the deaths to
inhalation anthrax. The latter explanation would constitute
prima facie evidence for violation of the BWC.
International investigations followed, some involving noted Harvard
biologist Matthew Meselson. His group's reports, although somewhat
critical, initially seemed to lend credence to the Soviet
explanation. However, subsequent findings and detailed witness
accounts left little room for doubt.
Today, it appears that the deaths were precipitated by a shift
worker at the microbiological installation who removed a critical
filter that had clogged. The filter happened to be on the output of
a drying machine used to remove liquid from industrial-scale
cultures of anthrax spores, which were being produced for
bioweapons. An aerosol of spores was released from the unit's
exhaust pipes over a period of several hours before the mistake was
discovered. Sverdlovsk suffered the single largest epidemic of
inhalation anthrax in history. In 1992, former Russian President
Boris Yeltsin formally acknowledged the true origin of the outbreak.
The current economic and political climate in the former Soviet
Union raises the disturbing likelihood that their bioweapons experts
will be forced to seek employment elsewhere, resulting in unwelcome
proliferation. The analogous problem arises for former Soviet
nuclear experts, of course, but bioweapons issues have received
comparatively little attention and scant resources.
The BWC was also clearly violated by Iraq, which established
extensive programs for the development of both chemical and
biological weapons under Saddam Hussein in the early 1980s. Details
of these programs only surfaced in the wake of the Gulf War,
following investigations conducted by the United Nations Special
Commission (UNSCOM) in charge of Iraqi disarmament. As a result of
these investigations, more is known today about the once-secret
bioweapons program in Iraq than that of almost any other nation.
Iraq maintained several distinct facilities, including those at the
Muthanna State Establishment (the principal chemical weapons plant),
Salman Pak (the main biowarfare research center, just south of
Baghdad), the "Single-Cell Protein Production Plant" at Al
Hakam (the main bioweapons production facility, allegedly built to
produce animal feed) and the Foot and Mouth Disease Center at Al
Manal (a site for biowarfare research on viruses).
The Al Hakam facility began mass production of weapons-grade
anthrax in 1989 and eventually generated at least 8,000 liters
(based on declared amounts). This plant was not bombed during the
Gulf War in 1991, and its true role in Iraq's bioweapons program was
not established until 1995, at which point the U.N. ordered its
destruction. Relevant portions of the facilities at Salman Pak and
Al Manal were also destroyed, either by the Iraqis themselves or
under direct UNSCOM supervision.
In the aftermath of the Gulf War, Iraq officially acknowledged that
it had worked with several species of bacterial pathogen??including
Bacillus anthracis, Clostridium botulinum and
Clostridium perfringens (which causes gas
gangrene)??and several viruses??including enterovirus 17 (human
conjunctivitis), rotavirus and camel pox. They also purified
biological toxins, including botulinum toxin, ricin and aflatoxin.
In total, a half million liters of biological agents were grown.
A Meaningful Bioweapons Treaty
All told, it's suspected that more than a dozen sovereign nations
possess some form of offensive bioweapons program, assuming one
includes some republics of the former Soviet Union. How can this
proliferation be controlled? One approach is to muster international
resources to enhance and strengthen the provisions of the
BWC??giving it some "teeth." This would include
verification measures that monitor treaty compliance, including
reciprocal inspection visits to suspected bioweapons facilities.
This is an essential component of modern arms-control regimes,
similar to those implemented for nuclear weapons treaties.
An international group of BWC participants has been convened since
January 1995 to accomplish just that, under the chairmanship of
Ambassador Tibor T??th of Hungary. It carries the ponderous name of
"The Ad Hoc Group of the States Parties to the Convention on
the Prohibition of the Development, Prohibition, and Stockpiling of
Bacteriological (Biological) and Toxin Weapons and on Their
Destruction"??or simply the "Ad Hoc Group." By now
the Ad Hoc Group has met for more than 50 weeks in Geneva. The draft
treaty they have prepared is as ponderous as the group's name: It
currently weighs in at several hundred pages, including an
astonishing 1,500 "bracketed" paragraphs??which denote
passages where there continues to be disagreement.
For the moment, progress of the Ad Hoc Group seems depressingly
stalled. Embarrassingly, the United States itself bears a direct
responsibility for many brackets, as it has steadfastly resisted
certain attempts to establish provisions for inspections. The U.S.
position is motivated by a desire to protect the interests of the
powerful American biotechnology sector, which fears that inspection
visits may be intrusive, or used as a pretext for industrial
espionage. There has been limited progress on this front with the
release last May of a joint statement by the Pharmaceutical Research
and Manufacturers of America and the Federation of American
Scientists who agreed on "managed-access" measures in
support of verification.
Another sticking point rests on a constitutional issue: It is one
thing for the U.S. government to authorize visits to its own labs
and bases, but can it mandate visits to privately held facilities?
Some have argued that such inspections may require warrants.
However, under the Fourth Amendment, warrants are necessary only if
actions rise to the level of a "search." Federal courts
have generally held that the subject of a search must enjoy an
expectation of privacy??but this standard is stricter for
individuals than it is for corporate entities, particularly for
industries that are highly regulated. Moreover, the Supreme Court
has already recognized that valid exceptions exist to the warrant
requirement??for example, for drunk driving, contraband and
immigration documentation??and compliance with a vital international
treaty certainly should qualify as a valid exception.
As the world's remaining superpower, the United States bears a
unique responsibility to take the moral high ground in this process,
assuming a leadership role in support of meaningful weapons treaties
that establish international norms. A way must be found before a
singular opportunity is lost.
Assessing the Terrorist Threat
Biological weapons have been called "the poor man's atom
bomb." By any measure, the economic outlay required to develop
offensive bioweapons capabilities is significantly less than that of
a nuclear program. Less is needed in the way of equipment and
infrastructure. The materials themselves are less rare. And less is
required in the way of specialized knowledge for the biological
aspects, since much of the information can be found in the public
domain. Worldwide, trained microbiologists overwhelmingly outnumber
nuclear physicists. All these aspects tempt not only nations of
concern, but also non-state actors. In fact, it seems far more
likely that biological agents will be used by terrorists than by
warring nations. Although the terrorist use of bioweapons is likely
to occur on a reduced scale, it could have worldwide ramifications
under unfavorable circumstances.
Little of real consequence has occurred along these lines, but shots
have been fired across the bow. In a bizarre episode that took place
in September 1984, more than 750 people fell ill with food poisoning
in The Dalles, Oregon. Thankfully, no one died. The cause of the
epidemic was not uncovered by health authorities at the time. But in
1986, Ma Anand Sheela confessed at trial that she and other
followers of the Baghwan Sri Rajneesh had spread salmonella
bacteria, grown on the cult's Oregon ranch, in salad bars in four
restaurants, all in an effort to keep voters from the polls so as to
influence a local election. After serving two and a half years in
federal prison, Sheela was released and deported to Europe.
Between 1990 and 1995, the well-financed Japanese apocalyptic cult
Aum Shinrikyo launched a repeated series of attacks on civilians
using both biological and chemical weapons. These culminated in the
infamous sarin gas release inside the Tokyo subway system in March
1995, which left 13 people dead and sent more than 5,000 to the
hospital. Before resorting to toxic gas, the group had reportedly
attempted, unsuccessfully, to mount attacks with biological weapons
on at least nine occasions over a five-year period. Aum Shinrikyo
boasted a dozen or so members with biological training and had even
gone so far as to buy a 500,000-acre sheep station in Banjawarn,
Australia to serve as a site for operations and to carry out tests.
The cult worked to develop biological weapons based mainly on
botulinum toxin and anthrax, although some members made an
unsuccessful trip to Zaire to obtain Ebola virus. They also
attempted, but failed, to acquire the rickettsia Coxiella
burnetii, which causes Q fever. In their earliest attempts to
carry out biological attacks, members of the cult sprayed
home-brewed botulinum toxin on Tokyo streets, near two American
airbases in Japan and at the Narita International Airport. All of
these attacks failed??most likely because they worked with the wrong
strain of C. botulinum (not all natural variants yield
equal toxicity) and because their misting device may not have been
up to the task. They later switched to anthrax, releasing spores in
Tokyo near the Imperial Palace, the legislature and a foreign
embassy. These tactics again failed, almost certainly because they
used a vaccine strain of B. anthracis. And again, their
spraying device may not have worked as intended.
Does this mean that we should all relax, because using bioweapons
turns out to be harder than the perpetrators thought? Is the
terrorist threat therefore exaggerated, as some have maintained?
Those who claim that biowarfare agents can be brewed in a garage by
practically anyone with a modicum of training may be guilty of
overstating the case, but although there has been no shortage of
exaggeration, that doesn't mean we're off the hook.
A lesson from the Aum Shinrikyo case is that any group bent on
developing offensive bioweapons capabilities must overcome two
significant problems, one biological and the other physical. First,
it must acquire and produce stable quantities of a suitably potent
agent. For a variety of reasons this is not the trivial task that it
is sometimes made out to be. Second, it must have an effective means
of delivering the agent to the intended target. For most, but not
all, bioweapon agents, this translates into solving problems of
dispersal. Programs in both the U.S. and the U.S.S.R. devoted years
of effort to perfecting these aspects.
But who is to say that a terrorist group might not find its own way
to imperfect solutions? After all, a terrorist works under entirely
different constraints. For one thing, there's no requirement for the
dispersal to be very efficient, because bioweapons terror attacks
are highly leveraged. If anthrax were released haphazardly in a
major U.S. city and produced only a handful of cases, the public
fear and disruption that would ensue might alone bring about the
intended effect. Our public health system simply isn't geared up to
handle an outbreak of this kind, which would, for a time, flood
emergency rooms. A terrorist group might also be tempted to finesse
the dispersal problem and release some contagious disease, with the
aim of starting an epidemic or even a worldwide pandemic. Or it
might choose to act covertly, perhaps attacking an economic target,
such as crops or livestock, rather than a human population. There
are many different options.
In my opinion, the terrorist threat is very real, and it's about to
get worse. And opinions do count here, because quantitative risk
assessment is a practical impossibility. As with nuclear war,
successful bioweapons attacks are characteristically "low
probability, high consequence" events. The expectation value of
the risk is the product of a very small and a very large number, and
such numbers carry great uncertainty.
The Smallpox Wildcard
All of which brings us to smallpox, the b??te noire of
bioweapons. Smallpox is a frequently lethal, highly contagious
disease caused by the variola major virus. By the end of the second
millennium, it had killed, crippled, blinded or disfigured one-tenth
of all humankind who ever lived. In one of the greatest achievements
of the 20th century, smallpox was finally eliminated after a
decade-long, worldwide health campaign, which was launched in 1967
under the auspices of the World Health Organization (WHO), under the
direction of Donald A. Henderson (now the director of the Center for
Civilian Biodefense Studies at Johns Hopkins University). The last
recorded case of smallpox occurred in Somalia in 1977, and the
disease was officially declared eradicated in 1980.
Although there is no cure for smallpox, it can be prevented with a
vaccine derived from the vaccinia virus. The U.S. Public Health
Service recommends re-vaccination every 10 years, but since routine
vaccination of the U.S. population ended nearly 25 years ago, few
Americans retain immunity today. The current stocks of the vaccine
are negligible. Fortunately, there has been some recent action to
correct this state of affairs. As of last September, the U.S.
Centers for Disease Control and Prevention (CDC) have contracted for
a 40-million-dose stockpile of the vaccine. The first batches of the
vaccine are slated to be ready by 2004. However, some public-health
scientists have questioned whether such a "small"
stockpile is adequate. In the event of a simultaneous terrorist
attack on several major cities, hundreds of millions of doses might
be required to prevent the disease from spreading.
Whether terrorists could get access to the smallpox virus is still
an open question. At the end of the heroic WHO campaign frozen
stocks of the variola virus were maintained in trust by two
organizations: the CDC and Vector, the Russian State
Research Center of Virology and Biotechnology in Koltsovo,
Novosibirsk, Russia. These stocks were originally scheduled to be
destroyed on December 31, 1993, but this date has been repeatedly
postponed as politicians and health officials debate the wisdom of
retaining or destroying the remaining virus, given the growing
bioweapons threat. For now, the decision has been deferred by the
WHO until 2002. A concern shared by many is whether the Russian
stocks are securely held. Ken Alibek has reported that Biopreparat
secretly prepared smallpox-based bioweapons up until at least 1992,
leading one to wonder how much viable smallpox virus might exist
outside the official Koltsovo depository. If any weaponized material
or viral stocks found their way to terrorist organizations, the
consequences could be disastrous. Simply put, smallpox represents a
direct threat to the entire world.
"Black Biology"
Beyond the smallpox scenario, what has people worried is the impact
of modern biotechnology. For better or worse, the world is in the
midst of a stunning revolution in the life sciences. Scientists have
already determined the complete genomic sequences for more than 30
microbes and even more viruses. The DNA code for the cholera
pathogen (Vibrio cholerae) was recently published, and the
genomes of more than 100 other microorganisms are now being
sequenced??including the bacteria that cause anthrax, plague,
dysentery and typhoid. Of course, the new information is critical
for answering fundamental and practical questions in biology and
medicine, and will be put to direct, practical use in a myriad of
health-related applications. But what about "black
biology"? Could biotechnology be used to produce a new
generation of biowarfare agents with unprecedented power to destroy?
Or is this just alarmist hype? No one can say for sure, but many
molecular biologists familiar with the relevant technologies seem
inclined to a pessimistic view.
A key reason for pessimism is the ease with which genetic
manipulations are now accomplished. Back in the summer of 1997,
JASON (a group of primarily academic scientists, which consults on
technical matters for the U.S. government and its agencies)
addressed the problem of next-generation bioweapons threats. The
JASON study explored a wide range of future possibilities open to
genetically engineered pathogens, including some that could be
achieved with the current state of the art and others that
are??happily??still some way off. The prospects are sobering. Both
bacteria and viruses may now be engineered to be qualitatively
different from conventional bioweapon agents. In terms of
bioweaponry, this includes imbuing them with such
"desirable" attributes as safer handling, increased
virulence, improved ability to target the host, greater difficulty
of detection and easier distribution.
Several broad classes of unconventional pathogens were identified by
JASON. These include "binary" bioweapons, which, by
analogy with chemical weapons, are two-component systems in which
each part is relatively safe to handle, but which become deadly in
combination, and "designer" variations on genes, viruses
and complete life forms, including chimeras that mingle existing
components. Once gene therapy becomes a medical reality, the
technology that allows the repair or replacement of defective genes
might be subverted to introduce pathogenic sequences.
"Stealth" viruses could be fashioned to infect the host
but remain silent, until activated by a trigger. New zoonotic agents
(those transmissible from animals to people) might be developed
specifically for bioweapon purposes by modifying existing pathogens
to seek human hosts. Finally, detailed knowledge of biochemical
signaling pathways could conceivably be used to create
"designer diseases."
Of course, some of these exotic possibilities seem downright
superfluous given the dangers posed by the current generation of
bioweapon agents. Then again, fusion-based hydrogen bombs seem
superfluous, given the destructive power of fission-based weapons.
For now, even the most rudimentary genetic manipulations could be
used to enhance a bioweapons threat, for example by introducing
antibiotic resistance into a weaponized bacterial strain.
Vaccination Woes
Anyone seeking to "improve" on wild-type anthrax might
begin by introducing antibiotic resistance in the form of a gene for
??-lactamase, which enzymatically destroys penicillin. Such a
transformation is rather straightforward, and similar to the kind of
thing done routinely today in molecular biology labs with
non-pathogenic organisms. Disease caused by a multi-drug- resistant
variant of anthrax would essentially be impossible to treat. Only
those with prior immunity, conferred by vaccination, would stand
much chance of survival.
Considerations such as this have helped to motivate the ongoing
campaign to vaccinate all 2.4 million U.S. active and reserve troops
against anthrax. The vaccination process, licensed by the Food and
Drug Administration (FDA), requires a six-dose regimen over an
18-month period. The modern vaccine is prepared from a cell-free
filtrate derived from an avirulent strain of B. anthracis.
By most accounts the current anthrax vaccine is as safe as, perhaps
safer than, typical vaccines, although every vaccine carries
residual risk. This is why the oral (Sabin) polio vaccine will soon
no longer be given to children in the U.S. Comprehensive vaccination
programs have reduced polio to such an extent that the risk
associated with receiving the oral dose, which leads to paralysis in
a minuscule fraction of cases, now outweighs the chance of getting
the disease itself.
Unfortunately, the U.S. military anthrax vaccination program has
been mired in controversy and scandal. Prior to the program, the
lone American company licensed by the FDA to produce anthrax vaccine
in the U.S. was the state-owned Michigan Biologics Products
Institute, and it was in danger of losing its license after
inspections raised questions about potency and sterility of the
vaccine. The troubled institute was bought out by Bioport, a company
apparently created solely to take over its assets and land the
lucrative government contract for the military. The most visible
corporate director of Bioport is Admiral William Crowe, former
chairman of the Joint Chiefs of Staff. Bioport thus became the
exclusive purveyor of anthrax vaccine and applied for FDA approval
of a Michigan plant to manufacture more. That approval is still at
least six months out. Meanwhile, existing inventories have dwindled,
and the military is running out of vaccine after administering fewer
than half a million doses (out of 14 million). As a result, they've
had to reduce monthly inoculations from 75,000 to 14,000 and suspend
injections for all but front-line troops considered at greatest risk.
In Senate hearings held in July 2000, Republican Senator Tim
Hutchison of Arkansas reacted to the situation as follows: "The
terms of the contract relief (between the Department of Defense and
Bioport) reduced the number of dosages to be produced by one half,
charged U.S. taxpayers almost three times as much as originally
negotiated, and provided Bioport an interest-free loan of almost $20
million. I am wondering who negotiated such a contract."
Issues of procurement and safety aside, the most disturbing aspect
of the anthrax-vaccination program is the unknown efficacy of the
new vaccine. A limited study, completed back in 1962 among mill
workers handling animal materials, demonstrated protection against
the cutaneous form of anthrax for an earlier version of vaccine.
However, no one is yet prepared to say whether the current
formulation will provide adequate immunity against acute inhalation
anthrax produced by a bioweapon. We may never really know, given the
obvious ethical considerations of experimenting with the vaccine. It
also seems possible that a strain of anthrax might be genetically
engineered to circumvent the immunity conferred by the present
vaccine. Does it therefore make sense to vaccinate all our military
personnel? Well, perhaps not all, but the risks to frontline troops
are very real, and the long interval required for the full
immunization schedule demands foresight. In the end, one is left to
make informed guesses.
The difficulties with the anthrax vaccine highlight an endemic
problem: The U.S. has precious little in the way of vaccine
production capabilities, and obtaining FDA approval for a new
vaccine protocol requires at least two years, generally more. The
vaccine industry faces serious issues analogous to the "orphan
drug" situation in the pharmaceutical industry. If a lot of
people are not dying of the disease, where is the market for the
product? And how does a manufacturer protect itself from ruinous
lawsuits? This is a topic that might be better addressed by the
public rather than the private sector.
Prospects
The Clinton administration has allocated some $1.4 billion during
fiscal 2000 to combat biological and chemical terrorism, a figure
that has provoked sharp criticism in some quarters. But this number
absolutely pales in comparison with the amount spent annually on
maintaining U.S nuclear capability, which is at least 30-fold
greater. It makes eminent sense to develop improved capability
against bioweapons threats, and we should not have to wait for the
biological equivalent of Hiroshima to rally our defenses.
There are also indirect benefits associated with such an
investment??ones that nuclear spending certainly can't claim to
match. Money spent on research to develop new types of sensitive
detectors and related monitors for biowarfare agents will almost
certainly carry over to the public-health sector in the form of
rapid, improved diagnostics for disease. Money spent on coordinating
and developing emergency response teams at federal, state and local
levels will also establish better mechanisms for dealing with
natural outbreaks of emerging diseases. Money spent on innovative
surveillance approaches for detecting biowarfare attacks should also
improve medical epidemiology. Money spent on vaccine research and
delivery may help to buttress our limited capacity to protect the
civilian, as well as the military, population. And money spent on
stockpiling and positioning depots of smallpox vaccine may turn out
to be the smartest hedge-bet of all.
Since 1945, a great many physicists have taken up the challenges
posed by nuclear weaponry, and worked hard at both the national and
international level to limit their destructive potential. But with
the notable exception of a few of the old guard, such as Donald
Henderson, Joshua Lederberg and Matthew Meselson, there has been
comparatively little involvement by biologists in bioweapons issues.
The case was put best by author Richard Preston, who wrote:
The community of biologists in the United States has
maintained a kind of hand-wringing silence on the ethics of creating
bioweapons??a reluctance to talk about it with the public, even a
disbelief that it's happening. Biological weapons are a disgrace to
biology. The time has come for top biologists to assert their
leadership and speak out, to take responsibility on behalf of their
profession for the existence of these weapons and the means of
protecting the population against them, just as leading physicists
did a generation ago when nuclear weapons came along. Moral pressure
costs nothing and can help; silence is unacceptable now.
Acknowledgments
The author thanks Jonathan Tucker, Amy Smithson, Jerry Joyce and
assorted members of JASON for comments and helpful discussions.