Vaccination is not a healthcare issue? Not sure what you mean by that.
The point is that I'm against these kinds of proposals because they perpetuate the idea that healthcare should be reserved for those who can afford it or deserve it, which should not be how we organize care. And is guaranteed to make insurance more unaffordable for some percentage of the population, adding to the cost for society of covering healthcare costs for those people when they inevitably need care (which we all do at some point). We know that a higher percentage of minorities are unvaccinated, who are already disproportionately uninsured as well.
So the whole approach is callous, contrary to the principles the left claims to care about, and economically unsound. People deserve to get care simply because they are human beings, not because they merit care by making healthy enough decisions.
Whether we should require vaccinations for employment in certain jobs is a whole other issue.