There's a third option of actually engaging in the discussion. You know, actually investing the efforts of silencing anti-vaxers into explaining the truth instead. And it's not like that option is unfathomable to the media. When the truth is aligned with their agenda, they are already experts in "fact-checking" and pointing out where their opponents are wrong.
The rules of debate say it's always better to refute the main argument and to address their issues. If you resort to ad-hominem attacks, appeal to authority, or just plain censorship, to me it is a confession that you do not have better information to add to the debate. Which implies that I'm right.