The simple, earthshattering brilliance of vaccines

One day in college, while I was eating at a University of Nebraska-Lincoln dining hall with a friend I’d known since middle school, we got on the topic of vaccines. This friend was an intelligent guy — he was majoring in engineering, had been on the Science Olympiad team with me, just a fellow nerd all around — so what he said next shocked me: He just didn’t like that vaccines got rid of the disease for you, like a one-time shortcut or cheat code that we’d just rely on again the next time the disease came around.

As you might already guess, the statement was shocking because my otherwise smart friend had the truth completely backward. And as measles, one of the most contagious diseases there is, spreads around the country and into Arkansas — all while our Health and Human Services secretary tries to have it both ways on vaccine safety and conspiracy theories — it’s worth being clear about the truth. Every vaccine you get does something amazing, whipping your own body’s immune system into shape to better protect you against a disease for months, years, even a lifetime.

Like so many of humanity’s greatest discoveries in health and medicine, the development of vaccination kicked off basically on accident. Two Englishmen, Benjamin Jesty and Edward Jenner, in the late 1700s pieced together that cowpox, an infection that was common among dairy workers, seemed to offer protection from the similar but far deadlier smallpox. (By this point, smallpox was likely responsible for tens of millions of deaths throughout human history and had decimated the Americas’ Native people.)

We didn’t have the scientific knowledge to understand it at the time, but the similarities between the cowpox and smallpox viruses allowed the workers’ immune systems to essentially train against a weaker enemy in preparation for a stronger one. Jenner soon set about providing this protection on purpose, in a really gross way, by transferring pus from cowpox lesions to an uninfected person.

Our methods have advanced, but the principles of modern vaccination (a word that stems from the Latin for cow) remain the same: giving our bodies practice, pushing them to act as if an infection is underway without all the fuss of illness and death. With cowpox, that happened by leaning on a dangerous disease’s cousin. In vaccines today, it happens by giving us weakened or disassembled versions of germs — whatever it takes to spook our white blood cells into putting up the biological equivalent of a Most Wanted sign, should the real thing ever show its face ‘round these parts.

To put it bluntly, vaccines are one of the most impactful, successful developments in our species’ history, helping us finally counter the diseases that have plagued us for millennia. Smallpox was one of humanity’s biggest killers; now it’s all but vanished. Polio was killing or paralyzing hundreds of thousands around the world every year before its vaccine; now it’s unusual to have a single case in the U.S. in a year. Measles was killing hundreds and hospitalizing tens of thousands more in the U.S.; now we’re rightly alarmed by a handful of deaths in the past few months.

Vaccines can have side effects, like temporary arm pain, and shortcomings, like causing rare complications, requiring boosters or merely softening the blow of a disease rather than slamming the door in its face. Nothing’s perfect. But the trade-off is more than worth it. What would you prefer: a 1-in-5 chance of hospitalization, 1-in-20 chance of pneumonia and 1-in-250 chance of death with unvaccinated measles, or one chance in several thousand of a complication from the vaccination?

Measles even has the sinister side effect of erasing previous immunity — ripping down those Most Wanted signs your body has been putting up your whole life. Imagine having to redo every shot and re-get every disease you’ve ever had because you didn’t get this one vaccine. It’s easy math and an easy decision.

And since you can hardly talk about vaccines without this coming up: No, vaccines don’t cause autism. Get your vaccine shots, sprays or patches, people.