Extinction - a good thing?

Smallpox has been feared since antiquity. Now it exists only in a handful of laboratories.

Smallpox was a leading cause of death in 18th century Europe. Efforts to understand and ultimately control the disease began in 1717 when the technique of variolation (inoculation) was brought from Constantinople. Sir Hans Sloane, later President of the Royal Society, inoculated children of the Royal Family using the technique.

In America, the Boston-based physician Zabdiel Boylston inoculated his own son and over 200 others during a 1721 epidemic. Further protective treatment was prevented by town elders who believed that Boylston was spreading the disease. The Royal Society's secretary, Dr James Jurin, responded to such claims by publishing statistical evidence gathered in the 1720s to prove beyond doubt the benefits of inoculation.

Edward Jenner's breakthrough use of cowpox to inoculate from 1796 coined a new word vaccination. The Royal Society was at first reluctant to publish Jenner's experimental account until more data was available. But Jenner's work pointed the way to how smallpox would eventually be defeated.

By 1980, the worldwide eradication of smallpox was declared by the World Health Organisation. Allan Watt Downie, a scientist fascinated by pox viruses since the 1930s, made a significant contribution to this endeavour. He studied the disease in the laboratory and in smallpox victims travelling through the port of Liverpool. Downie's work at Liverpool University informed the World Health Organisation's eradication strategy and he went into the field in India during the 1960s for the final push against smallpox.

Following outbreaks from laboratories in the 1970s, smallpox has been scheduled for extinction, but reprieved. The contagion has killed millions of people. Should humans kill smallpox?