In the late Eighteenth Century, the dreaded disease smallpox routinely killed approximately 10 percent of the British population – rising towards 20 percent in the overpopulated cities, where people lived under cramped conditions and horrible hygienic conditions. Mr. Jenner wondered, however, why dairy workers in the countryside seldom contracted smallpox. He discovered that they were practically immune, and speculated that the cause was exposure to the much less severe cowpox. Jenner tested his theory by inoculating people with pus from blisters on infected cows – and discovered that it worked!

The story of his success spread quickly and helped save countless lives. Mr. Jenner’s work also inspired the so-called Balmis Expedition, a three-year-long mission that helped spread the concept of vaccination against smallpox to Spanish America and Asia.

Jenner made quite a few other discoveries and received a number of prestigious awards in his lifetime. He even got a medal from Napoleon – during the war with England! – and had two English prisoners released. Because, as the French general put it, he could not “refuse anything to one of the greatest benefactors of mankind.” In modern time, BBC included Jenner in the list of 100 Greatest Britons.

Here, you’ll find the book that started it all – and without whom neither of us might be alive today.

An Inquiry into the Causes and Effects of the Variolae Vaccinae