Ten thousand years ago a deadly virus appeared in North-East Africa. The virus spread through the air, attacking skin cells, bone marrow, spleen and lymph nodes, smallpox had arrived.
In 1350 B.C. the first epidemic hit during the Egypt-Hittite war. Egyptian prisoners spread the virus to the Hittites killing their king and devastating his civilization.
Smallpox made its way around the world through Egyptian merchants, then through the Arab world with the Crusades and to America with the Spanish and Portuguese conquests. Since then, it has killed billions of people with an estimated 300 to 500 million victims in the 20th century alone. Smallpox didn’t discriminate, it affected Pharaohs, caused a terrible impact on the Greek and Roman empires, decimated the Native American population and killed 5 kings and queens, Balthasar Charles of Austria, Louis Le Grand Dauphin of France, Louis I of Spain, Louis XV of France and Mary II of England.
The fight against smallpox started long before modern medicine; in fact it began in 1022 A.D. According to a book called “The Correct Treatment of Smallpox”, a Buddhist nun living in a famous mountain named O Mei Shan in the region of Sichuan, would grind up smallpox scabs and blow the powder into healthy people’s nostrils after realizing that those who managed to survive the virus never got it again, and her odd procedure worked.
This procedure, variolation, slowly evolved and by the 1700’s doctors were taking material from sores and putting them into healthy people through four or five scratches on the arm.
Though many attempts were made, it wasn’t until English physician Edward Jenner made a new discovery that we obtained our modern solution.
When he was 13 years old he was an apprentice to a country surgeon and apothecary in Sodbury, near Bristol. One day he heard a milkmaid say “I shall never have smallpox for I have had cowpox. I shall never have an ugly pockmarked face.” Milkmaids and shepherdesses were renowned for their beauty because their skins were free of the scars smallpox caused.
Cowpox is a skin disease affecting cows that resembles smallpox. Smallpox and cowpox viruses are from the same family, but when a virus infects an unfamiliar host, as in this case of cowpox affecting a human, it is less virulent.
Later in his life, Jenner decided to test whether cowpox could be used to protect against smallpox. In May 1796, Jenner found a young dairymaid, Sarah Nelmes, who had fresh cowpox lesions on her hands and arms caught from the udders of her cow, Blossom. Using matter from her pustules he inoculated non-other than the 8-year-old son of his gardener, James Phipps. I mean, why test yourself or an adult when you have the child of one of your workers, right?
After a few days of fever and discomfort, the boy seemed to recover. Two months later, Jenner inoculated the boy again with matter from a fresh smallpox lesion and no disease developed. Jenner used cowpox virus in several other people including now himself and his children, proving that they were immune to smallpox.
The medical establishment, just as cautious then as now, deliberated at length and finally accepted Jenner’s discovery. The word soon spread around Europe and the method was used in the Spanish Balmis Expedition, a three-year-long mission to the Americas, the Philippines, Macao and China with the aim of giving thousands the smallpox cure. Napoleon, who at the time was at war with England, had all his troops inoculated and awarded Jenner a medal as well as releasing two English prisoners of war at Jenner’s request.
The most remarkable thing was that his discovery was made before Henle proposed in 1840 that infectious diseases were caused by germs, a theory demonstrated by Robert Koch. Decades later, Pasteur, inspired by Jenner’s experiments showed that attenuated microbes could be used to prevent diseases and proposed the term “vaccine” in Jenner’s honour. Vaccine comes from the Latin “Vacca” meaning cow.
After large vaccination campaigns throughout the 19th and 20th centuries, the World Health Organization certified the eradication of smallpox in 1979.
Recent studies say that the vaccine used to prevent smallpox was likely to be horse-pox. The latest evidence comes from historic containers when scientists sequenced its DNA, they found it most closely resembled the genome of horse-pox. Jenner himself wrote that he used material from both cows and horses in his experiments as he thought the origin of cowpox came from a virus that horses suffered from. Maybe we will have to start to say equine instead of vaccine!
Jenner is forever remembered as the father of immunology, but let’s not forget the milkmaid Sarah Nelmes, her cow Blossom who now hangs on the wall of St George Medical School in Tooting, and the poor little human guinea pig James Phipps, all protagonists of the discovery that helped eradicate smallpox.
Sources: Wikipedia; sciencemag.org; The origin of vaccines, Open Mind BBVA; How we conquered the deadly smalpox virus, Simona Zompi.