None of the New York parents who are refusing to vaccinate their children today were around the city in the summer of 1916, which is good for them and good for any of the kids they might have had. It was in that summer that 27,000 children nationwide were struck by a polio outbreak, 9,300 of them in New York. Of those 9,300 victims, 2,700 died. The Salk family at 116th St. and Madison Ave. escaped the scourge, meaning that their two-year-old son Jonas was spared. History notes that when he grew up, he had a little score-settling to do with the poliovirus.

That hard experience of a city and its people makes the sublime obtuseness, recklessness and flat-out numbskullery of some of today’s New York parents entirely indefensible. A deeply disturbing investigative piece in New York magazine reveals that fully 245 of the city’s private schools have vaccination rates that fall below the 95% level needed to ensure herd immunity — the protection that’s provided to the few unvaccinated members of a community because so many others are protected that a pathogen never gets a foothold. Of those schools, 127 fall below 90% and 37 fall below 70%. Nine schools fall in a dismal range of 18.4% to 41.5%. Numbers like that are the leading cause New York is suddenly suffering a measles outbreak, more than 50 years after the first vaccine against the disease was licensed.

'Messing with nature' is the whole point of medicine, given that it's nature that cooked up every disease that ever existed.

The anti-vaxxers all cite the same imaginary problems to support their resistance: Vaccines are linked to autism (they’re not), they cause autoimmune diseases (they don’t), they are “messing with nature,” as one pediatrician in a Marin County, Calif. practice that indulges parents who don’t want to vaccinate their kids or want to administer the shots on their own schedule, told Mother Jones Magazine. Um, OK.

But here’s the thing the anti-vaxxers need to know, for the one billionth time: You’re wrong. Really, it’s that simple. You’re trafficking in junk science, in thoroughly debunked science, in the dizzy stuff of rumor mills and conspiracy theories. And about nature? “Messing with nature” is the whole point of medicine, given that it’s nature that cooked up every disease that ever existed. You want pure nature? OK, die young.

The authorities cited by the warring camps ought to settle the matter all by themselves. On one side we have the likes of Jenny McCarthy and Kristin Cavallari. Nothing wrong with naked models, TV hosts, and fashion designers, but they’re not, you know, scientists. On the other side we have the World Health Organization, the U.S. Centers for Disease Control and Prevention, the National Institutes of Health, UNICEF, the Gates Foundation, the American Medical Association, the American Academy of Pediatrics, and virtually every serious medical journal on the planet.

So anti-vaxxers, you lose. Or actually, your kids lose.

Parents who oppose vaccines are not only misinformed, they’re spoiled, having grown up in a world that stands behind the berms built by the scientists and vaccine developers who came before them. If you’ve never seen measles — or polio or whooping cough or mumps — you have the luxury of believing they don’t exist.

“We live in a very healthy community,” said one of the sublimely glib doctors cited in the Mother Jones story. “The incidence of these diseases are very low, not only here but nationwide. And so it’s safe to do a modified vaccine schedule, in my opinion.”

But the incidence of these diseases is very low precisely because most doctors and parents don’t think the way you do and do vaccinate on schedule. “We live in a very dry community,” the doctor might as well have said. “So it’s safe not to maintain the levees and flood walls that have protected us until now, in my opinion.”

And so you drown; and so unvaccinated children get sick. The words “in my opinion” are not themselves some kind of rhetorical vaccine. They can, instead, be the pathogen. Like all pathogens, they can kill.

Write to Jeffrey Kluger at jeffrey.kluger@time.com.