Biohazard

One of the first researchers to observe nonspecific immunity in action was a Russian microbiologist named Ilya Mechnikov, who identified the first cellular components of immunology. Working in Italy between 1882 and 1886, he noticed that a collection of cells would migrate to the site of infection, where they would surround, swallow, and destroy foreign particles. Mechnikov called these cells phagocytes (they are now also referred to as macrophages or monocytes). His work, which earned him the Nobel Prize for Medicine in 1908, laid the foundation for the modern science of immunology.

It was not until the 1960s that scientists began to focus on the cells and molecules responsible for coordinating the body's nonspecific immune response against invaders. These include macrophages and granulocytes, as well as special proteins in the blood that interact to defeat foreign microorganisms in what is called a complement cascade. Another important component of nonspecific immunity is a remarkable group of molecules called cytokines, through which cells communicate to one another and pass on vital marching orders.

Cytokines form a bridge between specific and nonspecific immune systems. They are produced in response to viruses or bacteria, or to a general stimulus in the blood. Their function is primarily regulatory: they direct the magnitude of an immune response. They can suppress or stimulate the secretion of antibodies and macrophages, induce fever and inflammation, and prompt the growth and activation of a host of essential immune cells. Most cannot kill viruses or bacteria on their own, but they have been found to boost the immune system and to enable patients to respond to previously unproductive treatments. They have also been shown to increase the effectiveness of T and B lymphocytes including natural killer cells, which destroy pathogenic bacteria and cells invaded by viruses.

In 1957, European scientists identified the first cytokine. It was named interferon, because it appeared to interfere with the progress of viral infections. Three major types have been identified. Interferon took years to isolate, but by 1979 scientists at an American pharmaceutical firm had managed to reproduce one type — interferon alpha — artificially. Touted as the "antiviral penicillin," interferon entered the medical lexicon as a powerful tool for the treatment of illnesses ranging from hepatitis to Kaposi's sarcoma, a frequent symptom of AIDS. Scientist have since become more cautious in their claim, as interferon produced mixed results in lab tests and was found to cause side effects when taken in large doses. Nevertheless, it is widely used today.

The discovery of cytokines and other elements of nonspecific immunity represent an important step forward for medicine. Scientists in America have developed a treatment for AIDS that includes interleukin-2, another cytokine, and research into the effects of cytokines on tuberculosis and other diseases is under way in the Netherlands, Great Britain, Japan, France, and Canada. At least eighteen interleukins are well known to scientists today, and each year more are discovered.

Nothing will replace the long-term protection provided by vaccines against specific diseases, but boosting our nonspecific immune system may offer at least temporary protection from pathogenic agents and possibly could go even further. If administered in the crucial first hours after an attack — when authorities are still trying to identify which agent was used and organize a medical response — such a booster could help contain the crisis. It is a long shot, but everything I know about biological weapons tells me that this is far more promising than attempts to rig office buildings and public monuments with detection devices or to stockpile vaccines.

Ten years, almost to the day, after I was called to army headquarters in Moscow to brief Soviet colonels on how to load intercontinental missiles with anthrax and plague, I met with two U.S. Marine colonels in the fifth-floor conference room of an office building in Virginia.

The marines had driven up from their training base at Quantico, where they operate a think tank called the War-Fighting Lab. Despite the name of their lab, the marines came to discuss defense: how to protect troops against biological warfare and terrorism. Often the first on the scene in a military emergency, marines are exposed to the kinds of unconventional threats not faced by other branches of the armed forces.

On May 20, 1998,I had presented to the U.S. Congress a proposal for developing nonspecific immunological defense against biological weapons. At the time, national efforts were devoted almost exclusively to detection and vaccination — a week later President Clinton would propose a reserve stockpile of vaccines — and this unconventional approach was greeted with widespread skepticism. But things changed dramatically over the next six months.