This is completely different. Smokers and anti-vaxxers are harming the public in a significant way. I wouldn't care for smokers if they could only do it in a hermetically sealed room where no smoke escapes from. Neither would I care for anti-vaxxers who are completely segregated from society so they don't hurt herd immunity.

The argument against banning smoking in public is that it forces others to inhale the smoke against their will simply by sharing space, not that the person doing the smoking has no right to put it into themselves. In a sense, it is an anti-pollution law.

I agree with that. But I also think there is other reason for anti-pollution laws, which is in addition to saving people, also saving the Earth, too, which is also important (independently of if the people are saved; some people want to do so for the people but I think that is only a part of it).

And if someone does have a hermetically sealed room no smoke will escape from, I suppose that is OK, so shouldn't be illegal except forcing someone to do against their will.

You libertarians.

Please address their point about antivaxxers.

A libertarian might argue that that falls under restricting an individual's right to harm others. They might believe that individuals don't have the right to increase the risk to people who can't vaccinate for heath reasons, and they might believe that parents don't have the right to harm their children by depriving them of their health.