The Centers for Disease Control and Prevention is now running tests on six forgotten vials of smallpox recently discovered in an unsecured laboratory.
A 14th-century outbreak of plague known as the Black Death may have caused Europeans and Roma people to evolve to look more similar.
Scientists have confirmed the bacteria that caused the plague pandemic 1,500 years ago. Continue reading →
A new study shows how regional climate differences controlled the intensity of outbreaks of plague in China.