The answer to Brendan's question is that medical ethics in principle requires doctors to treat people based on need rather than perceived desert. Smokers, the obese, the physically inactive, reckless drivers after accidents, those injured in drunken pub fights, heroin users, etc get treated at a par with "innocent" patients. I think that's a compassionate way of doing things and it's hard to see how in the case of antivaxxers it could be done differently without opening up an ethical Pandora's box.