This should be a criminal offense. It's basically https://en.wikipedia.org/wiki/Endangerment in a more roundabout way.
Unfortunately the anti-vaxxers in Israel are extremely aggressive and they use a lot of fear tactics and deceptive “marketing”. An approximate translation of the largest anti-vaccine group in Israel’s Facebook page title is “Vaccines, an educated choice”.
I do think that more recently the tide has turned against them as Facebook has become much more aggressive in hiding their propaganda.
Personally, I hold the opinion that anti-vaxxers are more of a natural product of their environments than anything else. You can clearly see the distinction along the religious and educational boundaries, for example. Limiting the freedom of speech in attempt to silence them is not going to work, like it's not working in stopping any other kind of speech you don't like. Censorship is dangerous: it alienates people and prevents communication, effectively radicalizing those affected.
Whether it’s the right choice is obviously subject to debate.
[1]: https://twitter.com/AmarAmarasingam/status/13481478677399756...
Conflating the vaccine hesitant with the radicals you mention is done on purpose of course, but there’s a real cost. You are alienating and further radicalizing fence sitters. Censorship of open discussion can also be seen as confirming their possible view that vaccine manufacturers are ”hiding something“.