> There are a LOT of anti-vaxxers who disingenuously couch their advocacy as "I'm only asking questions".

And they quickly reveal their bad faith, at which point they can safely be ignored.

Or, if you don't feel like discussing it, it's easy enough to say "I don't know about that, but the anti-vaccine stuff sounds like lies to scare people so I decided to trust my doctor."

If honest questions are met with hostility, while the anti-vaxxers are friendly and "helpful", guess who's going to be more influential?