It was in the middle of the 18^th century when, as a boy, English physician Edward Jenner overheard a conversation that would one day save countless lives. What he overheard was a milkmaid explaining to someone that she would never have to worry about the disfigurement of the dreaded smallpox because she’d had a case of the much milder disease cowpox.

Surely it struck the young man as strange that this probably fairly uneducated woman believed her life, and her beauty, may have been saved by a cow, but the notion stuck with him as he grew. On May 14, 1796, Jenner inoculated an eight-year-old with cowpox laced pus. The boy ended up with a short-lived mild fever and some temporary general malaise, but was otherwise fine. Then two months later, Jenner exposed the boy to smallpox, and he developed no symptoms at all.

Dr. Jenner called his discovery “vaccinia,” derived from the Latin word for cow. He wrote up his findings, published them as An Inquiry into the Causes and Effects of the Variolae Vaccinae, presented them to the Royal Society, and faced ridicule from renowned naturalist Sir Joseph Banks and other very important men.

But some listened and experimented and discovered the same result. Edward Jenner, on the overheard musings of a milkmaid, had discovered a way to prevent smallpox infection that proved significantly safer than inoculation with the smallpox virus itself, which was a practice frequently undertaken by those who wanted to reduce their chance of dying from smallpox to one in forty from twelve in forty.

One physician thought the newfangled vaccine promising enough, that he sent Jenner’s work to an American colleague by the name of Benjamin Waterhouse, who served as Professor of Theory and Practice of Physic at Harvard Medical School. The American physician was so impressed by the research that on July 8, 1802, he vaccinated both a household servant and Waterhouse’s own five-year-old son, fortunately with great success. He would later go on to vaccinate his entire household and quite a few relatives in order to, according to him, “convince the faithless and silence the mischievous.”

Excited, Waterhouse next set up Board of Health trials in which vaccination by the cowpox-causing virus proved overwhelmingly preventative of smallpox infection. He faced as much resistance and ridicule as Jenner had, but he did have a powerful ally in then president Thomas Jefferson who sent him a fan letter in which he wrote: “Future nations will know by history only that the loathsome smallpox has existed and by you has been extirpated.”

Jefferson may have been a little bit premature in his statement, but through the continued efforts of Waterhouse and Jenner a skeptical population both in the US and England, and eventually throughout the world, increasingly sought vaccination. Then in 1980, the World Health Organization declared smallpox officially eradicated.

Gone. A disease that some historians estimate killed as many as two billion people throughout history is gone because of a gossiping milkmaid, an eavesdropping boy, and the influence of a committed community of medical professionals and those who trusted them.

I’m not a vaccine expert, though I’m glad to say I have more education than the average 18^th century milkmaid. What I do know is that the more opportunity viruses have to thrive, the more opportunity there is for variations to occur, and the more opportunity there is that one of those variations may not be thwarted by the vaccines we currently have. I also have many medical professionals in my life, all of whom are fans of vaccination in general, and right now, of the Covid-19 vaccines specifically.

I wouldn’t pretend that I could dispense medical advice, and I am well aware that every individual has a unique medical history and set of concerns that can produce a whole host of questions I might not even think to ask. And I know there’s a lot of confusing information out there. I also believe that how my fellow Americans want to live their lives is how they should live their lives. I get all of that.

So, I will not dispense advice or debate with you about whether or not you should get vaccinated against Covid-19. I won’t even consider you faithless or try to silence your mischief if you decide not to. All I will say, for whatever it may be worth, is that the members of my household, consisting of me, two teenage sons, and my husband who is a medical professional, have been vaccinated against Covid-19.

I’m grateful we had the opportunity and that we took advantage of it. I’m grateful that most of my extended family are vaccinated as well. I’m grateful for all those around me who have also done so. I’m grateful for cows and milkmaids, for Edward Jenner and Benjamin Waterhouse, and for the medical professionals who have made our most recent miraculous vaccines possible.

And if you have the opportunity to get vaccinated against Covid-19, I am so very grateful for that, too.