People are always shocked to learn that I wasn't vaccinated as a baby. I'm a science journalist, after all, and studied neuroscience in college. I believe in science, and science is unequivocal about whether babies should be vaccinated: They should be.

But my parents weren't so enamored with mainstream scientific authorities. We lived in a small town in rural Michigan, where my mom had also grown up and where everybody knew everybody else's business. We nominally had a family doctor — Dr. Burris, an osteopathic physician — but I don't remember ever going to see him as a kid, or ever being sick at all. (Once when I was 5 or 6, according to my mom, I came down with a bad cold, and my nanny threatened to quit if my parents didn't take me to a doctor. So I went, got antibiotics, and was fine.)

I didn't realize that being unvaccinated was odd until grade school, when my parents had to sign a form saying they objected on religious grounds. When I was 16, I had to get a tuberculosis skin test in order to volunteer at a nursing home, and at 17, I had to get a series of shots so that my college would let me live in the dorms. Otherwise, though, it rarely came up.

I haven't thought much about my vaccination history until this week, while covering the measles outbreak for BuzzFeed News. I realized that I'd never actually asked my parents why they didn't vaccinate me or my younger sister.

I knew it wasn't because of the (now thoroughly debunked) link between autism and vaccines; that research didn't make headlines until 1998, and I was born in 1984. I figured my parents' choice boiled down to their politics, which were of the conservative/libertarian/small-government variety. They were those people who refused to give Social Security numbers to anybody, for any reason. With a handful of like-minded friends, they created a group, called "Citizens for Improved Government," and published a newsletter taking aim at what they saw as an overreaching city government and school board.

It was fitting, I thought, that they refused state-mandated vaccinations, the most pervasive and successful public health strategy of all time. But I didn't know for sure. So I emailed my mom to request an on-the-record interview, and she readily agreed. After some small talk, we got around to the Disneyland outbreak.

"They're trying to connect it to the conservatives — it's the most ridiculous thing I've ever seen," she said over the phone. "It's the vegetarian people and the ultimate hippies who started the movement, and they're all liberals! It's not a political thing anyway; it's ridiculous."

I told her about my assumption — that her stance on vaccines came out of libertarian values. Was that true?

No, she said, that wasn't it at all. "I was totally pro-vaccines, really, until Dr. Taylor."

Dr. Taylor was my parents' dentist. He was part of the Seventh-day Adventist Church, which was somewhat unusual in our town. "They look at things differently," mom said. "They're vegetarians." My parents were decidedly not, but they respected this guy because he was well-educated.

A month after I was born, my parents took me to meet Dr. Taylor. He gave them a brand-new book, called How to Raise a Healthy Child in Spite of Your Doctor, written by a medical doctor named Robert S. Mendelsohn. The book seems to be a favorite among the alternative-medicine crowd, and Mendelsohn, a self-described "medical heretic," was apparently against heart surgery, water fluoridation, and "modern medicine."

That book changed everything, mom said. "There were a couple of chapters on immunizations, and that was what we zeroed in on."

Listening to her rattle off the book's specific claims about vaccines, I was surprised at how much time and consideration she had put into thinking through the data — or at least the data she knew about. Dr. Burris, an osteopathic physician who "was not into meds," my mom said, was also sympathetic to Mendelsohn and Taylor's ideas. In other words, all of the experts my parents knew and trusted were steering them against vaccines.

But they didn't just make a blanket decision about all vaccinations. When considering the MMR vaccine — a combination jab for protection against measles, mumps, and rubella — mom and dad analyzed the risk-benefit ratio of each disease, one at a time.