How a disease of cows saved hundreds of millions of lives

Would people innoculated with cowpox become cows? The cartoonist James Gillray lampooned the fear.

Would people inoculated with cowpox become cows? The cartoonist James Gillray lampooned the fear.

I’ve been looking back over 250 years of growing knowledge about the human body, the ills that befall us, and how to treat them. In her book Smallpox, Syphilis, and Salvation, Sheryl Persson points out that the idea of curing disease is a very new one. For most of history, and for many illnesses even today, physicians have treated symptoms and tried to keep the body alive long enough for it to cure itself.

smallpoxAs for eradicating a disease, we’ve managed to get rid of one, and it took us 180 years from the time a country doctor in England first published a pamphlet suggesting not just the possibility, but the method.

How can we who live in the West in the 21st Century imagine a society where a single illness killed one tenth of the population every year? Where a quarter of the entire population was killed or permanently scarred by that same illness?
Smallpox was no respecter of persons, killing kings and street beggars alike. It was responsible for one out of every three deaths in childhood at a time when a third of children died before they were nine.

It changed the course of history several times, contributing to the fall of Rome, altering the succession of the British throne and ushering in the Georgian era, killing the rulers of the Aztec and Incan nations and crippling their nations so the conquistadors could sweep all before them… The list goes on and on.

Death among the Mezo-Americans

Death among the Mezo-Americans

By the middle of the 18th century, England had learned the practice of variolation; fundamentally, the practice of rubbing a cut or scratch with material from a smallpox scab to give a healthy person a case of smallpox. As long as the person administering the treatment avoided both of the two major risks, the person had a far better chance of surviving the disease, and then they wouldn’t catch it again.

The risks? Doctors tried to find milder strains of smallpox by looking for people who were recovering, but sometimes they got it wrong. And—without a germ theory of disease transmission—some of them weren’t that careful about washing their instruments (or even their hands) between patients. Variolation was common during a smallpox epidemic, and doctors carried contagion from their dying patients to their well ones.

George III of England lost two infant sons to variolation within six months of one another. Still, a death rate of less than one in fifty was an improvement over the status quo.

A physician inspects the growth of cowpox on a milking maid' Credit: Wellcome Library, London. Wellcome Images A physician inspects the growth of cowpox on a milking maid's hand while a farmer (?) passes another physician a lancet. Coloured etching, c. 1800. Published: [ca. 1800]

A physician inspects the growth of cowpox on a milking maid’
Credit: Wellcome Library, London. Wellcome Images,

Edward Jenner, the country doctor I mentioned, drew on folklore to find a better way. While not the first to inoculate healthy patients with cowpox, he was the first to press his treatment on the medical community. Cowpox was a related disease, seldom fatal or even serious, and country folk had long known that milkmaids were immune to smallpox.

When, in 1796, Jenner inoculated his gardener’s son with cowpox taken from a local milkmaid, he founded the science of vaccination, and took the first step in the long road to the last natural case of smallpox, a hospital cook in Somalia in 1977.


I’ve been reading about illnesses and deaths in the 18th and 19th centuries, and about medical knowledge, for some of my books. In A Raging Madness, (Book 2 of the The Golden Redepennings) the hero is crippled after being hit by a canister shell (today we’d call it shrapnel) and the heroine is a doctor’s daughter and was her father’s apprentice. In the Mountain King series, the next book after The Bluestocking and the Barbarian is The Hermit and the Healer. My healer takes on a cholera epidemic at a girls’ boarding school, and needs to deal with the prejudice of the locals as well as the suspicion and anger of the reclusive parent of one of the girls.

I have one of my regular background characters dying of syphilis (the great pox—more about the medical history of that scourge next week).

And I’m still working out what will kill Mia Redepenning’s husband’s Javanese wife so that Mia can finally have her happy ending in Unkept Promises, Book 4 of The Golden Redepennings. (Something lingering, so she has time to send a letter halfway around the world to her English ‘sister wife’ to beg Mia to be a mother to her four little children.)

The first vaccination

The first vaccination


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