An Arkansas judge (Judge Susan Webber Wright, famous for the Paula Jones v. Bill Clinton case) just ruled that vaccination exemptions violate the First Amendment. Her solution -- not allow any nonmedical exemptions. Here is the AP Story. (Also here.)
The case came about because Arkansas, like most states, has a religious exemption for mandatory vaccination. A mom wanted an exemption, but was not a member of a recognized church with tenets against vaccinations. A much better solution would be to allow exemptions based on personal beliefs, as California does.