International Network of Engineers and Scientists Against Proliferation

Bulletin 19 - Bioterror and Bioweapons Control

Biotechnology, Ethics of Research and Potential Military Spin-off

Kathryn Nixdorff , Wolfgang Bender

The vast majority of microorganisms are of a harmless nature. Indeed, most have very beneficial properties that can enrich our lives, and many are even essential to our health and well-being. A few microorganisms can, however, cause infection and these are termed pathogenic, which means they have the ability to inflict damage or cause disease.^[1] Potential biological weapons can be found within the various groups of microorganisms. Poisonous products of microorganisms, plants or animals, designated as toxins, are also considered biological weapons. Some agents frequently named as having possible military use^[2] are listed in the table on this page.

The status of bioweapons

The 1972 Biological and Toxin Weapons Convention (BWC)^[3] was the first international treaty that banned a whole class of weapons. The core prohibition in Article I of the convention is based on a general purpose criterion which bans all work on biological agents for non-peaceful intents and purposes, but allows work on biological agents for peaceful purposes or in order to defend and protect against biological warfare. This duality between purposes permitted and prohibited under the BWC creates ethical dilemmas and uncertainties for scientists and technicians involved in biology and biotechnology.

At the time of the negotiation of the BWC, effective verification measures or complaint resolution procedures were not incorporated into the Convention.^[4] This was due partly to political difficulties in negotiating such measures at the time, but also to the false perception that biological weapons were relatively impractical from a military viewpoint.^[5] Today, however, the perception of the potential military utility of biological weapons has dramatically changed. Following the 1990-1991 Gulf War, investigations by the United Nations Special Commission (UNSCOM) revealed that Iraq had a major biological weapons armament program.^[6] Furthermore, former Russian President Boris Yeltsin indicated in 1992 that the former Soviet Union carried out an offensive biological weapons program from 1946 until March 1992.^[7] US sources suspect that at least ten other countries are developing biological weapon capacities.^[8] A discussion concerning the BWC and efforts to strengthen the Convention with a legally binding compliance enhancement mechanism is presented in a contribution by Iris Hunger in this issue of the INESAP Bulletin.^[9]

The status of biological weapons has also been changed over the past three decades by developments in biotechnology, which has been revolutionized by molecular biology and genetic engineering. The revolution in biotechnology was just beginning when the Convention entered into force in 1975: the first successful genetic engineering experiment was carried out shortly after the conclusion of negotiation of the BWC.^[10] This development was soon perceived as a potential threat to biological weapons control, and fears were raised that totally new types of microorganisms with qualities more suitable for battlefield use might be fabricated.^[11] As a result, biological defense research increased at what seemed to some observers to be an exponential rate.^[12]

Modifications of microorganisms of bioweapons relevance

Since the advent of genetic engineering, four categories of manipulations or modifications of microorganisms and their products have been the subject of discussion: 1. the transfer of antibiotic resistance to microorganisms; 2. modification of the antigenic properties of microorganisms; 3. modification of the stability of the microorganism toward the environment; and 4. the transfer of pathogenic properties to microorganisms.^[13]

All four kinds of manipulations are possible and are being carried out daily in research laboratories. Some of the most intensive research concerns the elucidation of the mechanisms of pathogenesis. This work is essential for combatting infectious diseases. It is hoped that the production of more effective vaccines with less side effects, better diagnostics and new therapeutic drugs will result from this research. At the same time, it is feared that the advances in biotechnology can be misused to develop and produce biological weapons.

Relevance of genomics

Genome analyses and nucleotide sequencing are being intensively applied to pathogenic microorganisms, with the aim of discovering and identifying new virulence determinants. It is hoped that targets for the development of diagnostic and chemotherapeutic reagents as well as vaccines can be defined in the course of these investigations.^[14]

The Human Genome Project, which was started toward the end of the 1980s, involves the sequencing of the entire human genome. The project aims to gain insight into the organization and function of genetic material and to provide a solid, molecular base for physiology and medicine. At the same time it will enhance knowledge about inherited genetic disorders and the development of cancer.^[15] Several aspects of the Human Genome Project generate controversy, including the possible commercialization of information gained from genome sequencing. In April 2000, Celera Genomics of Rockville, Maryland announced that it had sequenced all pieces of the human genomic DNA from one source.^[16] It will still take some time to reassemble the pieces into the proper order and many years to determine the functions of the various segments, but the achievement represents a major milestone.

Especially controversial is the Human Genome Diversity Project, which was set up in 1993 and aims to provide a comprehensive study of genetic variation across different human populations. The scientific merits of the project, including possible contributions to the understanding of human genetics and the improvement of health in human populations, go without question. However, it has generated a storm of moral, cultural and political controversy in which opponents have argued that it "smacks of racism, commercialism, exploitation and cultural imperialism".^[17] In particular, some critics have expressed the fear that the information gained from this project may be used to create genetic or ethnic weapons to target a particular racial or ethnic group.

However, several arguments speak against the possibility of ethnic or genetic weapons. Reports have pointed out that races do not exist genetically but are social categories reflecting slightly different genetic constitutions, which are in part the result of local adaptations in populations living under different environmental conditions.^[18a-c] These differences reflect only gradients of change in the frequencies of allelic (alternative, slightly different) forms of genes in particular populations. In other words, the full complement of allelic forms of a certain gene will be found in all populations, but the frequency of the expression of those allelels will vary among the populations. It must also be remembered that there is generally more genetic variation within groups than between group.s^[19] Another difficulty in the creation of an ethnic or genetic weapon is the efficacy of the delivery system. The problem is not unlike that encountered today in certain gene therapy approaches, with respect to the delivery of a sufficient amount of the gene to the correct target cells and the maintenance of the expression of the gene.^[20] To date, these delivery systems do not function satisfactorily. However, research is underway with the aim of improving of delivery systems for cancer therapy, so advances in this area can be expected.

Both the report by Bartfai et al.^[21] and the one by Dando et al.^[22] conclude that ethnic biological warfare is not a practical possibility today. At the same time, they caution that it cannot be ruled out that genome sequencing projects will provide information that can be used to produce biological weapons directed at racial or ethnic groups in the future and suggest that this work be carefully monitored: "...there is a need to keep careful watch on research in this area and to give attention to means by which malign developments can be thwarted. Whilst we should hope that genetic weapons are never developed, it would be a great mistake to assume that they never can be, and therefore that we can safely afford to ignore them as a future possibility."^[23]

It should be remembered that biological warfare may be directed against plants and animals as well as humans. Mark Wheelis^[24] has rightly pointed out that while ethnic weapons targeting specific groups of humans are at present not very realistic, equivalent weapons targeting specific varieties of plants and animals are a real possibility. For example, agriculture, particularly in many developed countries, employs monocropping of large acreages with genetically identical cultivars, which would be highly vunerable to genotype-specific weapons.^[25]

In regard to genetic weapons being directed against humans, it is known that single-nucleotide polymorphisms (SNPs) are the most frequent type of variation in the human genome. Possibly, certain SNPs may appear more frequently than normal in isolated populations (linkage disequilibrium) and therefore might serve as genetic markers of such populations.^[26] Additional concerns lie in the possibility of creating genetic markers in a particular population, for example, by immunization or targeted delivery of new genes to cells using a gene vector. Such marked populations may then be vunerable to genetic weapons.

Ethical decision-making

Because of the pronounced dual-use aspects of biotechnologies, it is very difficult to advocate the prohibition of any type of biological research. Therefore, we propose monitoring research activities and applying ethical decision-making rules to research in order to enhance transparency and to serve as an early warning signal for activities not justifiable as peaceful.

Up to now, ethical decision-making processes in relation to questions concerning war and peace have not led to a concensus. Dissension is found primarily in the way in which peace is secured or made. Two models are open for consideration: on the one hand, there is the model of a just war for defensive purposes supplemented by the model of a just deterrence; on the other hand, there is the model of a constructive and prospective peace ethics. Both models are based on historical experience. The model of a just war and just deterrence points to the historical fact that there has always been military aggression. In addition, an anthropological root for this historical experience has been named. It can be seen in the human tendency toward aggression that has a connection with a phobia for something foreign, which is itself basically determined by evolution. In the light of this historical conviction and the potentially aggressive constitution of humans, it would be a morally justifiable necessity for a state to protect its citizens from nonjustifiable military aggression by resorting to military measures themselves.^[27]

The second model is that of a constructive and a prospective peace ethics. A prospective ethics considers the decisions that are to be made at that moment from the perspective of a middle or long-term outlook for the future. Peace ethics concentrates on leaving fewer war-promoting conflicts for following generations than the ones perceived at the present, and it also aspires to reduce the military force potential. Peace ethics has been called constructive because it allows the design of general social, political and international frameworks that will encourage and support a peaceful resolution of conflicts.

This model also claims a historical experience basis. No peaceful state can emerge from the act of answering violence with counterviolence. Indeed, this can only lead to a new constellation of dominance which must be surmounted in order to establish a truly peaceful state that is more than just the absence of war.

In order to focus more directly on ethical aspects of research in relation to the dual-use character of such activities, specific examples of work from the recent literature will be examined in the following and ethical decision-making processes based on the second model describing a constructive and prospective peace ethics will be discussed using these examples.

(1) Genetic profiles as a contribution to global epidemiology

The need for effective methods of identifying microorganisms with increased virulence or transmissibility as well as antibiotic-resistant strains has prompted a novel approach to molecular typing primarily designed for global epidemiology. This approach is called multilocus sequence typing (MLST),^[28] which involves using the polymerase chain reaction (PCR) to amplify DNA fragments of a limited set (for example seven) of designated genes of a particular bacterium and then sequencing the PCR products either manually or by using an automated sequencer. For each gene, deviating sequences in different isolates of the bacterium are designated as alleles of that gene and the alleles of the seven loci provide an allelic profile, which unambiguously defines the sequence type of each isolate.

The technique has been successful in identifying antibiotic resistant clones of Streptococcus pneumoniae isolated from an outbreak in Taiwan, and in tracing the origin of these clones.^[29] In this regard, some isolates were identified as members of a multiply-antibiotic-resistant clone originating from Spain, while others had a far east origin.

Another successful application has been made in the case of Neisseria meningitidis strains.^[30] Especially pertinent to BWC compliance, a similar approach was recently used to study genetic relationships within Bacillus anthracis.^[31] Even though this bacterium is one of the most genetically homogeneous pathogens known, the authors of the study were able to determine genomic regions containing enough variability to allow discrimination among different Bacillus anthracis isolates. The method has proved its usefulness in identifying the anthrax strain used in the recent terrorist attacks in the US.^[32]

Nevertheless, the work has dual-use aspects connected with it, above all with regard to sequence information that would be provided when allelic profiles are determined. As mentioned above, the method was originally based on sequencing of conserved genes. These are genes whose sequences do not change rapidly over time. The products of such genes are usually involved in general metabolic processes that are vital for the cell, and the sequence information would in all probability be of little use to a potential aggressor. However, in the case of some pathogenic microorganisms, a genetic profile may have to include sequence information on antibiotic resistance or virulence genes. It should be noted that in the study on Bacillus anthracis.^[33] this was not the case, as the sequences used for profiling were those found in DNA areas known as variable number tandem repeat (VNTR) sequences, whose function is essentially unknown.

Based on ethical considerations, the determination of genetic profiles on infectious agents is to be endorsed. This is despite the dual-use aspects of this research, which, in comparison with other examples, is not very pronounced anyway. The endorsement is primarily due to the medical relevance of these activities in serving global health security, diagnostic capability and in opening up possibilities for therapeutic intervention. In regard to biological weapons, the determination of genetic profiles has a three-fold impact. In the case of a biological warfare attack the identification of the agent as well as its source would be possible. The same would hold for the case of an accidental escape of agents from storages that are prohibited by the BWC. Finally, genetic profiles of agents would greatly enhance the effectiveness of investigations at suspected production and storage facilities. All in all, these activities could do a great deal to promote global health and at the same time help build confidence in a biological weapons control regime.

(2) Transfer of virulence genes to Bacillus anthracis

Russian researchers have transfered hemolytic toxin genes from the bacterium Bacillus cereus (a non-infectious soil bacterium, but a few strains have been implicated in food poisoning) to virulent strains of Bacillus anthracis.^[34] The toxin in question is called cereolysin. Its hemolytic properties are apparently determined by phospholipase enzymes, which damage cell membranes (especially red and white blood cells) and kill the attacked cells. An unexpected result was obtained. The normal Bacillus anthracis vaccine strain failed to protect against a challenge infection of hamsters with one engineered virulent strain of Bacillus anthracis. Thus, transfer of additional virulence genes to a pathogenic Bacillus anthracis enabled it somehow to evade the defences provided by the normal vaccine. The mechanism of the evasion is not clear.

The researchers claimed that they undertook the study in order to investigate changes in immunogenic properties of vaccine strains in connection with hemolytic characteristics. It cannot be denied that knowledge gained by these experiments concerning the behaviour of the engineered strains might be useful for defence purposes (which are permitted under the BWC). However, this work is definitely dual-use: such a strain of Bacillus anthracis could be a prototype potential biological weapon able to evade protection by known vaccines.

This research is non-justifiable from an ethical standpoint. In light of the many problems involving therapeutical approaches that must be solved and the limited financial resources available, only those medical research activities that show promise of producing a healing effect are justifiable.^[35] Another reason lies in the realm of the ethics of ecology. Scientific civilization has burdened the environment, which is the indispensable habitat of humans, with considerable and threatening sources of potential danger. Therefore, in the absence of necessity, it is simply not acceptable to add to these burdens as would be the case represented by the example of man-made infectious agents with increased pathogenicity.^[36] Such work does not meet the purpose of scientific research, which is not only to provide firm knowledge but also to serve the preservation and further development of humankind. On the contrary, it is destructive. It can nonetheless be argued that this work could provide information that might be valuable for defence, but its worth has to be weighed against the added risks that it creates.

Summary

In the last decades, we have experienced a revolution in biotechnology that is still on the rise and has not yet reached its peak. With the use of these modern technologies, the mechanisms regulating pathogenic processes of infectious agents can be elucidated more readily and precisely, which could lead to the development of more effective therapeutics and diagnostic reagents. This research is clearly essential. However, the possible misuse of biotechnology for the development and production of biological weapons is an actuality that cannot be ignored. Preventive arms control criteria emphasize the need for monitoring developments early in the process, that is, at the level of research. At present, clear distinctions in human populations have not been determined and the possibility of developing ethnic weapons seems remote. However, plant and animal populations are highly vunerable to genotype-specific weapons, and concerns about genetic marking of human populations to make them more vunerable are real.

Kathryn Nixdorff , Deparment of Genetics (nixdorff@bio1.bio.tu-darmstadt.de), and Wolfgang Bender , Department of Theology and Social Ethics (wbender@hrzpub.tu-darmstadt.de), Darmstadt University of Technology, Germany.