Smallpox is the only human infectious disease to have been eradicated worldwide. Researchers have now recovered fragments of ancient DNA belonging to variola virus, the virus that causes smallpox, from the naturally mummified remains of two Indigenous people buried in northern Chile.
For centuries, smallpox caused devastating epidemics. Its severe form, variola major, killed around 30% of those infected, although the rate varied between outbreaks and populations.
