What is the percentage of American's that are not vaccinated? Do we know? And what vaccines are currently "required?"
I'm sure that info is around somewhere. Maybe some of our more talented and prolific googlers will find it. Note that a lot of anti-vaxxers tend to be found in clusters these days, rather than some kind of even distribution across the country, so a general number may not indicate a specific enough picture of this development.
Also, not all those not vaccinated are anti-vax; they may be ineligible to get them, or they may just not have gotten around to doing it or may not know their vax status. My husband is not anti-flu shot, he just never gets around to getting it done. He always thinks he's going to go get it tomorrow.