I'm not obligated to do many things. I do however wear a mask because it is the right thing to do. This isn't a moral dilemma.
If society continues to coddle anti-vaxers, it reinforces a positive incentive for selfish behavior, which in turn creates a negative drag on overall well-being. At a certain point, society shouldn't allow the selfish acts of small group of individuals undermine the well-being of society at large.
Obviously, there would need to be ample warning and a concerted effort to educate everyone on consequences. Once these requirements are met in this hypothetical, I believe the moral thing to do is to stop wearing masks and stop social distancing.
That said, this is an idealized hypothetical. In reality, there will be many people who can't get vaccinated for reasons that are not selfish. In this case, there is still a moral dilemma, but I'm unsure on how I'd approach it. Surely, asking 200 million people to wear masks for another year to save 1 life isn't worth it. The question is where to draw the line.