Smallpox was a major killer of children and babies.  In some ancient cultures, smallpox was such a major killer of infants that custom forbade the naming of a newborn until the infant had caught the disease and proved it would survive.  Smallpox changed the course of history and it has been involved with war, exploration, and migration.  Repeated epidemics swept across continents decimating populations and killing hundreds of millions of people over the centuries.  In the 20th century alone, it killed 300,000,000 people.  Freedom from smallpox was declared in Bangladesh in December, 1977 when a WHO International Commission officially certified that smallpox had been eradicated from that country.

Humans likely acquired smallpox from one of the pox-like diseases of domesticated animals in the earliest concentrated agricultural settlements of Asia or Africa when humans began to maintain herds of livestock.  Observations of typical smallpox skin rashes on Egyptian mummies dating 1100 to 1580 BCE; theories that ancient Egypt was an early smallpox endemic region.  Historical and medical records from Asia: evidence of smallpox-like disease ancient China and India.  Earliest unmistakable description of endemic smallpox first appears in 4th century CE China, 7th century CE India and Mediterranean, and 10th century CE SW Asia.  These earlier Asian descriptions suggest that pandemic smallpox originated in East Asia.  Smallpox can be transmissioned in many ways such as face to face contact, infected body fluids, scabs, contaminated objects and airborne spread.  Spread of smallpox was spread through wars, movement of populations, trade routes and caravans, slave trade.  Vaccine became safer in 1891 when Monckton Copeman demonstrated germicidal effects of glycerin on vaccine.  In 1939, researcher Allan Watt Downie showed that the smallpox vaccines being used in the 20th century and cowpox virus were not the same, but were immunologically related.  At that point, the name “vaccinia” was used for the virus in smallpox vaccine.  Vaccine potency and efficacy prior to the invention of refrigerated methods of transportation was unreliable.  The vaccine would be rendered impotent by heat and sunlight, and the method of drying samples on quills and shipping them to countries in need often resulted in an active vaccine.