Throughout history, devastating epidemics of infectious diseases have profoundly impacted
human populations. In the mid-14th century, the Black Death, a plague epidemic, killed
approximately one-third of Europe’s population. During the Great Plague of London (1665–
1666), more than 15% of the city’s population perished. In 1918, an influenza pandemic caused
an estimated 20 million deaths worldwide, surpassing the fatalities of World War I. Another
significant epidemic was the Yellow Fever outbreak in Philadelphia, USA, in 1793, which
claimed 5,000 lives out of a population of 50,000.