Biohazard

New viruses can appear without warning, and viruses once considered harmless to man can suddenly morph into killers. They can be responsible for devastating epidemics, such as AIDS or Ebola, or they can be benign, like the virus that causes some warts. Some viruses only infect plants. Others target animal life. Arboviruses, transmitted by insects, usually aim for the brain, muscles, liver, heart, and kidneys. Enteric viruses lay siege to the gastointestinal tract, entering the body through contaminated water or food. Respiratory viruses, responsible for measles, mumps, and chicken pox, are airborne viruses that assault the nose and throat. More than one hundred different viruses have been identified as causes of the common cold.

Of all the diseases that have tormented mankind, smallpox has left the oldest and the deepest scars. Recorded as early as 1122 B.C. in China, it altered the course of history, ravaging eighteenth-century Europe and decimating the native populations of North America.

Smallpox comes from the pox family of viruses, which assault the upper respiratory tract. Variola major, the scientific name by which the smallpox virus is known, is patient and systematic. It will begin by insinuating itself into cells close to the surface of the skin and in the neural system. The smallpox virus sheds its shell as soon as it enters a live cell, and quickly begins to multiply. Viral transcription begins almost immediately, inhibiting DNA synthesis and thereby preventing the cell from activating its defense mechanisms. Once the virus has inserted its genetic information into the host cell, proteins and enzymes are created to help it mature and develop. The progress of the virus can be mapped by the spread of tiny pink spots from the face and arms to the lower regions of the body.

Smallpox symptoms were once familiar to every doctor. After a quiet incubation period of five to ten days, the virus manifests itself suddenly. The first stage of the disease brings high fever, vomiting, headache, and a strange stiffness. This can last from two to four days. Within less than a week, small spots will begin to develop, forming a rash around the face. As the rash spreads over the following week these spots will develop into painful blisters. In the normal course of the illness, the blisters form scabs that linger for several weeks until they dry and fall off, leaving scars. More severe forms of black or red pox can lead to death within three to four days.

The modern struggle to conquer smallpox began in 1796, when the British physician Edward Jenner observed that milkmaids who had contracted a mild form of pox virus from cows appeared to be immune to smallpox. Jenner injected an eight-year-old boy with material taken from lesions on the hand of an infected milkmaid. The boy developed a slight fever. Two months later Jenner inoculated him with smallpox, but he didn't contract the disease. The physician concluded that the milder strain, which he named vaccinia, provided immunity.

Smallpox "vaccine" — the name chosen to honor Jenner's work— became the principal instrument for tackling the disease. His discovery, the first vaccine, revolutionized medicine.

On May 8, 1980, the World Health Organization announced that smallpox had been eradicated from the planet. The last naturally occurring case was reported in Somalia in 1977, and no new cases had been detected in three years. The WHO recommended the discontinuation of smallpox immunization programs, observing that there was no longer any need to subject people to even the negligible risk connected with vaccination.

The international agency simultaneously adopted a resolution restricting the world's stocks of smallpox to four sites, where limited quantities would be available for research purposes. A few years later, the sites were narrowed down to two: the Centers for Disease Control in Atlanta and the Ivanovsky Institute of Virology in Moscow.

The conquest of smallpox generated a special feeling of accomplishment in the Soviet Union: the worldwide crusade against smallpox had been a Soviet initiative. Moscow first proposed the campaign at a World Health Organization meeting in 1958, and its sponsorship of vaccination programs in the third world won it admirers everywhere. Russia had suffered its share of smallpox outbreaks over the centuries, finally managing to eliminate the disease in 1936, after a decade-long immunization program sponsored by the fledgling Bolshevik government.

Soon after the WHO announcement, smallpox was included in a list of viral and bacterial weapons targeted for improvement in the 1981-85 Five-Year-Plan.