It’s not misinformation. It’s faith.

Ifirst met the anti-vaxxers in the spring of last year, at the height of the measles outbreak. It was just after sunrise, in the dim light of Jamaica Station in Queens, New York, where we had arranged to meet a bus to Albany. As we waited, in the glow of the brake lights on Sutphin Boulevard, freezing rain beaded red on the station’s glass walls. Most of the women were meeting in person for the first time. But they knew each other well from endless conversations on an anti-vaccination group on WhatsApp.

WhatsApp, more than most other technological platforms, illustrates an uncomfortable truth for journalists: we all have our own informational realities now. MSNBC viewers live in a separate world from Fox News viewers and a different one again from readers of the Financial Times. I wanted to explore how those realities work, and how they are likely to develop. The ways they undermine, and even replace, reporting. An issue as sensitive, and as prone to misinformation, as vaccination seemed a good place to begin. I had followed the anti-vaxxers’ conversation since the measles outbreak reached a crisis point in March.