Set a price high enough that this becomes clearly a good thing: what about $25k/person, spent directly on vaccines for others? I've been thinking about the whole "public vaccination" virtue signaling that politicians have been doing. The most ethical path would be to be immunized publicly as a politician at the same time as your risk group rather than before, ideally as the last person in your risk group so you have skin in the game. Whoever is overseeing the vaccine program should go last, for skin in the game.