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The White Lie at the Heart of Vaccine History

A milkmaid did play a role in how vaccines were born, but it’s not how you remember it

Stop me if you’ve heard this one before. Dr. Edward Jenner invented vaccines because of an observation he and he alone made. You see, milkmaids were renowned for their beauty. At a time when smallpox was endemic and was scarring the faces of the people who survived it, Jenner noticed that milkmaids would always escape from this dermatological blight. Why was that?

He intuited that their exposure to cowpox when milking cattle had given them protection from smallpox. And just like that, Jenner tested his brilliant hypothesis on a young boy by vaccinating him using material from a cowpox pustule, and the boy was proven immune from smallpox. Vaccines were born!

It’s a story that has legs, a veritable quadruped trumpeting the genius of this brave scientific mind. This tale is so good, it can be found on authoritative websites, like the Centers for Disease Control’s and Encyclopedia Britannica’s. St. George’s University of London and the London School of Hygiene and Tropical Medicine both put forward the yarn as canon in the history of vaccines (as does Pfizer!), and we find it repeated in Forbes and the Guardian. The PBS NewsHour goes further and puts words in one milkmaid’s mouth. Witnessing an outbreak of smallpox in the English countryside, this loquacious milkmaid is said to have told Jenner, “I shall never have smallpox for I have had cowpox. I shall never have an ugly pockmarked face.”

The problem with this simple story is that it is a boldfaced lie: not apocryphal, but confirmed as having been made up. You might even say it was propaganda.

The gamble of variolation

Before we had vaccines, there was variolation and it predated Jenner by centuries. Variolation was meant to protect against the horrors of smallpox.

Smallpox is an old scourge. Scientists have found what appear to be traces of its telltale pustules on Egyptian mummies that are a few thousands of years old. Unbeknownst to our distant ancestors, smallpox is an infection caused by the variola virus, with “variola” originating from Latin to mean, in this context, “mottled” or “a pimple.” Smallpox was a highly infectious disease. Different strains of the virus caused two forms of the infection, with variola major killing nearly one in three people who caught it. Its survivors were often left with pitted scars on their skin. Sometimes, they lost their sight. As humans left their African cradle and started exploring, then colonizing the world, the variola virus followed, bringing with it death and disability.

But humans are clever, and multiple people on the planet independently came up with the idea of variolation, also known as inoculation. It was used in parts of Africa. Bostonians in the early 1700s heard about it from an enslaved man, Onesimus, who was from what is now called Libya. In China, inoculation was mentioned in writing as early as 1549, although it might have been a few hundred years older. And there are apocryphal claims that the method was also used in India for thousands of years. The true history behind inoculation’s multiple origin stories may forever be lost to the tides of time.

The technique consisted in taking material from someone’s smallpox pustule and introducing it into another person’s body. A hair of the dog that bit someone else, if you will. It could be rubbed against a superficial cut that had been made on the arm, or the ground-up pustule material could be blown into the nose using a long pipe. We may scratch our heads at these mental images, but the idea was sound: to create a more localized infection that would hopefully not kill you and that, it turns out, would give you lifelong immunity against smallpox. While the disease itself had a stunningly high mortality rate, variolation was much safer. In the absence of vaccines, it was a worthy gamble.

The variola virus spread around the world and variolation sheepishly followed, and it eventually made its way to Great Britain, being popularized by the wife of a British ambassador, Lady Montagu, who lived in Constantinople and saw how harmless smallpox was to the Turks, who had adopted variolation.

The year was 1717. It would take an additional 79 years before Edward Jenner would demonstrate the worth of what would supplant variolation: vaccination. But how we get there is a little complicated.

A lie is born

What follows took place in the West Country, an area of South West England. To reach it now, you would drive for two and a half hours west of London. The story first focuses not on Edward Jenner but on a different doctor, John Fewster.

Fewster was inoculating the people of the West Country against smallpox using an improved version of variolation devised by the surgeon Daniel Sutton and his father, both of whom Fewster was partnered with in his practice. When he inoculated people, they would develop a pus-filled blister on their skin. But some people, crucially, did not show any sign that they had been inoculated. Fewster thought it was unusual. One day, Fewster variolated a farmer, whose skin likewise did not react to the procedure. And it was the farmer who told him that he had had cowpox “to a violent degree.”

Cowpox is a skin disease we now know to be caused by a virus similar to the one responsible for smallpox. Cows affected by cowpox will display papules and ulcers on their udders and teats. When a human catches the disease from a cow—or from rodents, which are more likely to infect humans with the virus—we see red blisters on the fingers, hands, or face. When the hand milking of cows was common, cowpox often spread to humans in this way.

So it was not Jenner puzzling over the beauty of milkmaids unscarred by smallpox. It was Fewster being told by a farmer that he had had cowpox. Fewster then began asking the people he inoculated whose bodies did not respond to the procedure, and they all confirmed it: they had also had cowpox previously.

Fewster described this important link to the members of a medical society that met at an inn near the town of Thornbury. The year was 1768 and medical conferences did not exist quite yet. Even medical journals themselves were rare, with the first one to be published in Britain being released in 1731. Local physicians instead would meet in informal settings and exchange information. Present at the meeting when Fewster described his discovery was Daniel Ludlow, a doctor, and his brother Edward, an apothecary. They practiced in the nearby town of Chipping Sodbury. Daniel had a 19-year-old apprentice at the time. His name was Edward Jenner.

Jenner would become a house surgeon in London the following year, before returning to the West Country and formally joining the medical society Fewster belonged to. In the intervening years, the discovery that a lack of pustulation after inoculation could be due to a prior exposure to cowpox had spread throughout this area of England, talked about by physicians and farmers alike. By then, however, Fewster had lost interest in his discovery. Inoculation was safer than getting cowpox, and cowpox did not, it seemed, always provide protection against smallpox.

This is where Jenner picked up the baton from Fewster. Over the next 25 years, he had two important realizations. The reason why people exposed to cowpox did not always develop immunity against smallpox was because the word “cowpox” was clumsily used to refer to three different diseases: a Staphylococcus infection, milker’s nodes, and an infection by the cowpox virus. The first two had muddied the waters. Second, even though a natural cowpox infection could be dangerous, he reasoned that inoculating people with it, in much the same way he was doing with smallpox, would be safer.

Milkmaids have had little to do with the story thus far, but one dairymaid is about to play a role now. In 1796, Sarah Nelmes, a milkmaid, catches cowpox in the middle of a local outbreak. Edward Jenner takes material from her hand sore and uses it to “vaccinate” a healthy eight-year-old boy named James Phipps. Subsequently, he tries to give the boy smallpox twice. “No disease followed,” he would go on to write. James was immune to it. The crude cowpox “vaccine” had protected him from smallpox, and Jenner himself would refer to it as “vaccination,” from the Latin for “cow.”

Hurray for vaccines, except that the story is not so simple. Jenner was not the first one to have introduced cowpox material into a human to induce immunity against smallpox. In 1774, Benjamin Jesty, a farmer in Dorset, had done it on his family, using a knitting needle and pus from an infected cow. A handful of others, including Peter Plett, a teacher from Kiel, also beat Jenner to it. Jenner was not a pioneer, but he documented his experiments and tried to get them published.

Then there was the opposition. Country doctors who were used to smallpox inoculation were disinclined to switch to a new intervention for which Jenner initially provided very little evidence. Moreover, this new “cowpoxing” did not give lifelong immunity to smallpox, and Jenner had also put forward the strange notion that cowpox ultimately came from an infection of the hooves of horses which would mutate when it infected cows. This whole vaccination business quickly became highly contested.

And so, a lie was born. In order to rehabilitate Edward Jenner’s reputation after his death, his first biographer, John Baron, created the milkmaid myth. He wanted to reduce the role Fewster had had in the invention of vaccination and elevate Jenner’s. This brilliant discovery—that exposure to cowpox could immunize you against smallpox—had actually been made by Jenner’s observation of beautiful milkmaids, went the story. Baron even wrote that Jenner repeated this claim on his death bed!

When we think about it, though, and consider its context, this legend makes little sense. Who ever said that milkmaids were renowned for their beauty? As pathologist and medical historian Arthur Boylston writes in his two-part exposé on the myth, the milking of cows in the 1700s was not even limited to girls. “No one ever suggested,” he continues, “that cowboys had smooth complexions.” And outbreaks of smallpox and cowpox were sporadic. Every milkmaid was not exposed to both. There would have been milkmaids (and cowboys) with smooth skin and others with the scars of smallpox.

But it is a lovely story, and lovely stories elevate historical figures to the status of heroes. They simplify messy histories and give us the observant geniuses we crave.

Origin myths are particularly common. We want to believe that modern placebo research began when Dr. Henry Beecher ran out of morphine during World War II and injected a soldier in pain with saline, but no first-hand account of this bit of serendipity has been found. We want to believe that crafty scientists at the Hawthorne Works factory could get the female employees to work harder by just changing their environment, but the true story is filled with sloppy research and misogyny.

It wasn’t Jenner noticing the smooth complexion of the milkmaids around him. It was Fewster being told by a farmer that he’d had cowpox before. Vaccines have proven themselves over time to be a fantastic tool for public health, but they were not the creation of a single man. They were experimented with by Jenner and many of his contemporaries, building on an inoculation technique that had popped up all over the world, with yet others confirming Jenner’s findings via replication, and vaccines would go on to be refined and perfected over centuries by countless researchers. The smallpox vaccine itself would lead to the announcement in 1980 of the global eradication of smallpox, no small achievement.

The stories we tell impact how we view the world. Science is complex and few people deserve all the credit for their discoveries. My hope is that, before the year is over, the hyperlinks above to the many sources that repeated the milkmaid myth will show a different, more accurate story of how vaccines came into being.

Take-home message:
- The story that Dr. Edward Jenner realized that milkmaids were immune to smallpox because of their exposure to cowpox was a lie made up by his biographer to rehabilitate his image
- The link between smallpox and cowpox came about when Dr. John Fewster tried to inoculate a farmer against smallpox and noticed there was no skin reaction, and the farmer told him he had had cowpox before
- Several people contributed to the invention of vaccines, from the many who independently came up with their predecessor, variolation, to Fewster and Jenner, as well as the handful of people who used cowpox material to provide protection against smallpox years before Jenner did his experiments


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