How deadly was variola major smallpox?

Variola major was a highly lethal form of smallpox, historically recognized as one of the world's most-dreaded plagues. During epidemics, the disease killed approximately 20 to 30 percent of its victims, with children being particularly vulnerable.12

In the most severe cases, patients often developed a deep red, hemorrhagic rash and frequently died from the toxic effects of the virus and the body's inflammatory response before the characteristic smallpox eruption could even develop. For those who survived the infection, the disease often left a lifetime of disfigurement through pockmarked scarring and, in some instances, resulted in blindness. Due to its extreme virulence and potential for mass mortality, the eradication of smallpox in 1980 stands as a monumental achievement in global public health.312