Rinderpest, a highly contagious cattle disease that killed millions of cows—leading to the starvation of countless people—over thousands of years, was declared eradicated in 2011. It’s only the second virus in history after smallpox ever to have been extinguished from the planet.
Until now, research samples of the highly contagious virus have remained in secure laboratories around the world—creating a risk that rinderpest could return and once again wreak havoc on cattle populations.
Source: https://now.tufts.edu/articles/world-without-rinderpest