|1979||An accidental release of anthrax spores from a Russian military base in Sverdlovsk kills between 40 and 1,000 people. The number remains unknown because of a massive Soviet cover-up.|
|1984||Attempting to disrupt a local election, members of a religious cult poison 751 residents of The Dalles, Oregon, by contaminating restaurant salad bars with salmonella.|
|1995||A dozen commuters are killed when members of Aum Shinrikyo, another religious sect, intentionally release Sarin, a type of nerve gas, on a Tokyo subway.|
|1996||An unknown person leaves muffins contaminated with a rare and dangerous bacteria in a Texas hospital.|
|1998||FBI agents seize small amounts of a substance reported to be anthrax from two men in Las Vegas.|
|2000||A Texas man is indicted for causing an anthrax scare, becoming the first person in the nation to face such charges. He left a vial of what was alleged to be anthrax , but which actually contained water, in a bin at the U.S. Postal Service mail center.|
|2000||Anthrax contamination threats are made against numerous Planned Parenthood clinics across the U.S. So far, none has been carried out.|
While there is no actual treatment for smallpox, Englishman Edward Jenner, in 1796, used the related cowpox virus to create immunity to smallpox. The word vaccination derives from "vacca," the Latin word for cow. Modern versions of Jenner's vaccine gave complete immunity from smallpox, as long as periodic booster shots were taken. But if the booster shots are not continued, the degree of immunity provided by the vaccine gradually declines, over several years, to zero.
In the 20th century, the worldwide vaccination campaign against smallpox achieved amazing results."
Although its use is banned by international convention, anthrax has long been the most popular subject of study for bioweapons research. While it is not contagious from human to human, very small quantities of anthrax spores released into the air could kill or sicken large numbers of people. Anthrax is an especially dangerous biological weapon because it can survive for long periods in the environment. According to WHO estimates, if 50 kilograms of anthrax spores were released along a two-kilometer line upwind of a city of 500,000 people, 125,000 would become infected within three days, of whom 95,000 would die.
The airborne form of the disease is far more dangerous, causing lesions in the lungs and brain.