Since vaccinated are spreading this around nearly as much as unvaccinated, the involuntary manslaughter argument is moot. Getting your own vaccine doesn't help other people not die...only you. Even high-vaccination regions are having waves of infection that dwarf previous ones. (Israel, Scotland, Hawaii)

That said, allowing civil suits to punish people that gave you a virus that killed you, would be effective to keep both vaxed and unvaxxed careful and staying at home while sick. Hard to prove where you got it, but just a few successful suits will keep people honest.