An obese person can reasonably argue that they're addicted to food and denying them medical care related to metabolic disease is unfair.I would not be surprised if a health-insurance provider tried to find some clause in its contract that allowed it to deny payment if a patient refuses vaccination - or at least charge them out-of-network rates. No idea if it would stand up in court, but I would not be surprised if someone tried.
the problem is that people do engage in other unwise behavior and that does not negate their health insurance - like a morbidly obese person who won't stop eating and develops diabetes or other problems. in a perfect world, the insurance company would have the right to say - get treatment, go see Dr. Now, or we cut off your insurance.
Refusing to take a vaccine with zero evidence to back it, is purely a person choosing to be an asshole. Punishment is deserved.