US doctor and epidemiologist Donald Henderson, who led a successful campaign to wipe out smallpox worldwide, has died at the age of 87.
Hailed as a "giant" in the field of public health for his work in the 1960s and 70s, Henderson died of complications after breaking a hip.
One of the world's deadliest diseases, smallpox killed hundreds of millions of people in the last century alone.
Apart from causing great pain, it often caused lesions on the face and body.
And it killed about one in three of those infected.
It was officially declared to have been eradicated in 1980 - the first infectious disease to have been fought on a global scale.
