While I believe that children should be immunized against communicable diseases, this is a gross violation of parental rights and, potentially, the 1st Amendment. If any of the students are Christian Scientists --who believe that prayer is the only legitimate remedy to disease -- then forced medical care will be in blatant violation of the Free Exercise clause. The First Amendment does not just protect behaviors that we don't find absurd and dangerous.
The parents of more than 2,300 Prince George's County students who failed to get needed vaccinations could face fines of $50 a day and up to 10 days in jail if their children do not meet the state's immunization requirements, county officials said yesterday.
There is an argument that this is a "public health issue" but -- as is most often the case -- this is a private health issue. Most kids will be immunized, and thus unaffected by the choices of others.
The best argument for forcing this is the child's rights (viz. health) versus the parent's rights (autonomous decisions relating to their own children). Unless the child expresses desire -- against the will of the parents -- for immunization, the parents have the right to medically treat their child how they see fit.
If this were a case of neglect, that would be one issue, but "improper" lack of precaution does not qualify as neglect. Such interpretation would open up a Pandora's Box of "unreasonable" parenting decisions that may run counter to conventional wisdom.
Leave the parents alone.
UPDATE: (2013) I've noticed this post has, for some reason, gotten a few views recently. I stand by the First Amendment problems and that incarceration is an inappropriate punishment, but I've realized since I wrote this regarding the whole "private" versus "public" issue, that people who have weakened immune systems--whether via HIV, Lupus, old age, or whatever--can be dramatically, even fatally, affected by these decisions. It's not in my bailiwick to say what should be done, but I don't believe incarceration is really the best answer.
Generally speaking, the threshold for which we put our fellow human beings in cages should be much higher than it is today. -jpb