The Life and Death of Smallpox

Smallpox is one of mankind's worst scourges, caused by an airborne virus with a 30% fatality rate. Known since ancient times, the disease gradually spread throughout the world as a result of colonial expansion and the slave trade. The pandemic was still responsible for nearly 300 million deaths in the 20th century. The discovery of vaccinia led to the eradication of smallpox in 1980 after a worldwide vaccination campaign. Recent advances in ancient DNA technology have allowed the historical record to be completed, revealing a surprising genetic flexibility of the smallpox virus that may explain variations in virulence from one era to the next. It remains a threat to humanity today, as viable viruses stored in laboratories could become biological weapons against non-immune populations. Recently, we have also witnessed the emergence of worldwide epidemics of the closely related monkeypox virus, which appears to be adapting to the human species. The history of smallpox provides a unique panoramic view of the life and death of a plague.