Does someone who opposes media-driven thinking (with supporting science to show why) about any one vaccine get lumped into "anti-vaxxers" in your mind? Because that all-or-nothing thinking fallacy is a key symptom of the problem.

If they have a factual basis for their views that's fine.

But in general I was talking about folks who have, for whatever reason, said things like "oh we're not vaccinating our children", meaning all vaccines.

There is no reasonable basis for this outlook.

Try to have that discussion. It's enlightening.

In what sense?

The only thing it can really do is inform me what sort of bizarre misinformation they have bought into. Unlikely ever to repair the drop in my opinion.

I think you may find out that the "bizarre misinformation" is a bit more nuanced than you think, and the issue is not about facts at all.

I spent some time talking to antivaxxers; I've shared my impressions in a parallel subthread:

https://news.ycombinator.com/item?id=10878136

I understand all that, that's not enlightening. I am well aware of the emotional motivations behind the position.

They dropped in my estimation because they allowed this emotional reaction to endanger their children.