I hadda laugh at this vax map of the US. Not the map per se but the caption. Since when were Michigan, Ohio, Kansas, Missouri, Kentucky, and even southern Illinois, "Southern states"? Notice, too, that any counties over 50% are all lumped in as NOT "under-vaxxed". When my wife was working in a private school, any time the vaccination rate for any of the common childhood diseases fell below 90% your got a call from the State. Gradations above 50%--not just below 50%--might show an even more clustered effect.