On 9 December 1979, the eradication of smallpox was certified by a panel of scientists following what the World Health Organisation describes as “one of the most successful collaborative public health initiatives in history.”
Origin and spread
The earliest evidence of smallpox dates back to the ancient Egyptians. Mummies from the period known as the New Kingdom of Egypt, between the 16th and 11th centuries BC, have been found to have skin lesions similar to those caused by the disease.
Trade and travel spread the disease through Asia during the early centuries of the Common Era, and returning crusaders hastened its proliferation across Europe during the 11th and 12th centuries.
The subsequent arrival of Europeans in the Americas in the 16th century brought catastrophe to the native populations, who possessed absolutely no immunity to the disease. Historians suggest up to 90% of the indigenous populations of North and South America may have been wiped out – a scale of devastation far beyond the capacity of the European invaders.
Smallpox killed about a third of those it infected. Mary II of England and Louis XV of France were just two of its high profile victims. Who knows how the history of England might have been altered had it claimed another, Elizabeth I, who contracted the disease in 1562. She bore its scars for the rest of her life, concealing them with white lead paint.
During the 10th century a process was developed to fight the disease. It began in China and India and was called variolation. It involved inoculating healthy people with mild doses of smallpox in order to build up their immunity.
This procedure carried a serious risk that subjects might develop the disease in earnest and die as a result. However it achieved some success and by the 17th century the practice had spread to Europe and the Americas.
The major turning point came in 1796. Edward Jenner, a British scientist, heard of a theory that milkmaids who suffered from the relatively mild virus known as cowpox never contracted smallpox.
He put the idea to the test. Taking a sample of pus from a milkmaid suffering with cowpox, Jenner inserted it into an incision in the arm of a young boy. He then inoculated the boy with smallpox and found that he was immune to the disease. The theory was correct. Jenner had produced the first ever successful vaccine.
Use of the vaccine gradually spread. Around the world, countries began vaccinating their populations en masse.
The road to eradication
In 1959 the World Health Assembly resolved to eradicate the disease entirely. By this time smallpox had been all but wiped out in Europe and North America but countries remained susceptible to outbreaks caused by individuals bringing the disease back from abroad.
The last natural case of smallpox was in Somalia in 1977. Ali Maow Maalin was working in a hospital when he contracted the disease, developing a fever on 22 October. He was diagnosed and made a full recovery. Unfortunately Maalin died of malaria in 2013 while working with the polio eradication campaign.
The last death from smallpox occurred in Birmingham, England in 1978. Janet Parker worked at the Birmingham University Medical School. Her office was located one floor above the Medical Microbiology Department where research into smallpox was underway. Somehow Janet contracted the disease, and died on 11 September.
On 9 December, 1979 the eradication of smallpox was certified by a panel of scientists, having carried out a global study. The following year, on 8 May, their findings were officially endorsed by the World Health Assembly.
Image: A cartoon highlighting the concerns about Jenner’s vaccine. it shows patients actually turning into cows! ©LibraryofCongress