As scientists scramble for a way to overcome Covid-19, the world is also marking a pertinent anniversary: humanity's only true triumph over an infectious disease with its eradication of smallpox four decades ago.
On 8 May 1980, representatives of all World Health Organization member states gathered in Geneva and officially declared that the smallpox-causing variola virus had been relegated to the history books, two centuries after the discovery of a vaccine.
Smallpox is a highly contagious disease that was transmitted via droplets during close contact with other people or contaminated objects, sparking high fever and a rash that left survivors permanently disfigured and often blind.