A CDC website noting areas with high chances of COVID outbreaks would be sufficient. The vaccines aren't 100% effective, so if you're in a high risk group you'd likely want to know which areas of the country to avoid.
But how would a website help high-risk individuals to know which unvaccinated individuals to avoid? Another idea could be mandatory tattoos for science deniers - the tattoos would have to be on a conspicuous place like the hand or forehead and visible from a safe enough distance to give people time to put on extra masks. This could be more "humane" than putting them in solitary confinement, but it's more likely to incur a taxpayer expense.