Super-plague could reappear.

The deadliest plague ever to hit mankind killed between 30-50 million people during the 6th century AD—nearly one half of the Earth’s population (Times of Malta, January 28, 2014). “Some 800 years later, the Black Death wiped out 50 million Europeans between 1347 and 1351” (ibid.). Recently unearthed remains of two 1500-year-old victims in Bavaria, Germany, showed the disease to be a different strain of the same bacterium that caused the Black Death in the fourteenth century. This has led scientists to conclude that “If the Justinian plague could erupt in the human population, cause a massive pandemic, and then die out, it suggests it could happen again” (ibid.).