It's disappointing that so many of the immediate root comments in this discussion continue to so thoroughly engage in straw man binary thinking and misunderstand what Free Speech is and entails.

To the first, the goal here is harm reduction in the form of the slowing the spread of infection, not a black and white magical changing of everyone's mind. No one has any illusions that existing anti-vaxxers will in any way be cured by steps like this, but the point is to reduce and slow the numbers of new people who will be infected by anti-vax thinking. Anti-vax thinking is like a disease itself, multiplying and spreading through regular human channels and exploiting our existing frameworks and thinking. Just as quarantines or vaccines themselves do not cure somebody who is already infected with a real world disease, quarantines and "vaccination" won't themselves cure somebody with corrupted thinking. But that doesn't mean they aren't useful tools, because real lives are on the line, and the system does have a certain amount of give and take in terms of what the critical level is for herd immunity (fortunately, since there will always be a small fraction of people with genuine medical issues like compromised immune systems). It's not necessary to keep everyone in the population vaccinating, with many it's only around 90-95%. It's understood that anti-vaxxers will mutate in response to new efforts to resist them, and in turn containment steps must also adapt. Nothing odd about that. It is and will always be a process as with many things in life.

Just as in the real world concentrated groupings of people, faster travel, and faster shipping systems can accelerate the spread of existing and new strains, social media which brings together many people and accelerates their exchanges could also be a vector. Success for any given effort comes from how much is slows things down for a time, that's all.

To the second, for various reasons many people have gotten the odd notion in their minds that "Free Speech" is about ideas being equal, or about it being free. It isn't, and never was. Quite the contrary, free speech is important precisely because ideas are not equal, and in fact most of them are trash. The goal is to try to make a process that, over long periods of time, will tend to eventually sift out better ideas and adapt to changing conditions that make older discarded ideas worthy of consideration again. Further, centralized power inevitably faces pressure to crystalize and serve smaller interests. So if the coercive centralized physical power of government (or equivalent entities) is used to control actual thoughts and expressions, the result long term has tended to be poor.

However, that very much does not apply to social pressure, or to whether individual private people/entities choose to associate with given ideas and/or lend them their own private economic support. Not doing so is a critical part of Free Speech as well. If somebody thinks ideas are truly awful, they can and should deny any support, lobby others to deny support, ostracize those with such ideas, etc. Fighting such pressure and bearing the consequences is itself part of the gauntlet that ideas must face, and always have faced. None of this is new. People have the right to go create their own services, groups, and put their own soap boxes out, but others have the equal right to have nothing to do with them. The arguments back and forth are at the heart of the process, and the process is never, ever done.