How did the smallpox vaccine changed the world?

Smallpox was finally controlled by the development of the world's first vaccine in the late 1700s, but fears linger that a few cells remaining in Petri dishes ... read more

Smallpox epidemics continued through the 20th century until vaccination programs were regulated and implemented around the world. In 1980, the World Health Organization declared smallpox completely eradicated, but samples of the virus remain in two laboratories in the United States and Russia, prompting fears of biological warfare should the virus land in the wrong hands. read more

Vaccination became widely accepted and gradually replaced the practice of variolation. At some point in the 1800s (the precise time remains unclear), the virus used to make the smallpox vaccine changed from cowpox to vaccinia virus. read more