THE death date of smallpox is clear. After killing more than 300 million people in the twentieth century, it claimed its last victim in 1978; two years later, on 8 May 1980, the World Health Assembly declared that the variola virus, which causes smallpox, had been eradicated. But the origins of this devastating virus are obscure. Now, genetic evidence is starting to uncover when smallpox first started attacking people…
This article first appeared in Nature on 23 July 2020. To continue reading, click here (paywall).