Prevention, Not Treatment
Since the time of Galen and Hippocrates, medicine’s purpose has been to heal the sick. While that remains the noblest of undertakings, a British doctor named Edward Jenner thought medicine could be something more. What if, he surmised, you could prevent people from getting sick in the first place?
That idea took root in 1796, when he noticed something unusual about milkmaids. Those who worked closely with cows and contracted an illness called cowpox didn’t contract the horror that was smallpox. Exceptionally contagious, smallpox killed hundreds of millions, or even billions, of people since prehistory, sometimes causing the collapse of entire civilizations.
Cowpox, by contrast, caused many of the same symptoms as smallpox, yet they were less severe in nature, and the disease was not fatal. So Jennings tried something that would change history: He drained some pus from a milkmaid’s active cowpox blisters and persuaded a farmer to let him inject the pus into the arm of the farmer’s son.
Then, in a move that would get him barred for life from any modern medical association, Jenner injected the boy with smallpox pus. The boy became mildly ill but did not develop smallpox, and he fully recovered in a few days.
Thus was born the smallpox vaccine, and a vaccination campaign that lasted until the World Health Organization declared the disease — one of humanity’s greatest scourges — eradicated by 1980.
Born alongside the smallpox vaccine on that day in 1796 was its fraternal twin, vaccine therapy, otherwise known as immunology. Since Jenner’s discovery, vaccines have been developed for many other diseases. To name a few: measles, rubella, diphtheria, mumps, polio, meningitis, hepatitis A and B, influenza, rabies, yellow fever and tetanus.
The impact of immunology on the human race is incalculable — almost. Early in 2014, the Centers for Disease Control and Prevention quantified it just a little bit. It estimated that the vaccines given to American infants and children over the past 20 years will prevent 322 million illnesses, 21 million hospitalizations and 732,000 deaths over the course of those lifetimes.