Is there actually any evidence of this happening? I would be somewhat surprised given the public interest in everyone getting vaccinated ASAP. With insurers required to cover all associated costs 100% with no deductibles or cost sharing etc and the rest of the population handled by the federal government I doubt you'd ever see a bill if you had a reaction and needed medical attention on site.
Viper GTS
Dunno, not my concern, not being under a private system. Just going on the basis of what Jaskalas said of his worries. Even if it's not true for most people, the fact that some might _think_ that's a possibility might suppress demand for the vaccine, which is a bad thing.
Also from what I've heard of US friends and their travails with medical insurance* it wouldn't surprise me if it happens to an unlucky minority.
* (e.g. being assured by the hospital's representative that the hospital accepts their insurance, then finding out after initially seeing the consultant that it actually doesn't, so now they've been stuck with the bill for the consultation but can't actually get any treatment from it - the whole system sounds like the worst of all worlds, to me, being just as subject to bureaucratic snafus and endless paperwork as a state-run one, but without the public-service ethos)