For example, there's a good chance that you are a carrier of CMV or EBV. Both of those can kill others.
It's the difference between killing somebody in a car accident and killing somebody in a DUI car accident.
I restrain the 'hammer' for diseases that are 'easily preventable'. IE the ones we have long-standing vaccines of proven safety for.
That's asserting a "positive right", and it's incompatible with libertarianism. It's also morally wrong.
I'll restate my belief: Do as you will, so long as it doesn't harm none consenting parties. Besides, while a good portion of those who remain vulnerable even while vaccination is available know about it, the vaccine itself has a failure rate, thus the more protected EVERYONE is the more people have been vaccinated. Indeed, as an absolute number, until recently these unknowing vulnerable people outnumbered the knowingly unvaccinated, medical issues or not.
If you get the first symptoms of the flu, do you isolate yourself to prevent its transmission to others until you're sure it's not the flu?
Actually, yeah, I do. If I have to go out, I wear a mask. They're more effective at catching the infectious droplets that cause infection when worn by the infected person anyways, and even if it's not the flu it's something I don't want to be passing around.
I also get the flu shot, and at least for me, it's worked.