At most Universities, and I assume other educational public institutions, it is mandatory for students to receive certain vaccines. There are waivers for religious or medical reasons that will allow the student to be on that campus without receiving the required immunizations.
However, if there is an outbreak, such as mumps in Iowa last year, the students who do not have their immunizations up-to-date or who have these waivers are not allowed on campus until the infectious time-period has passed, which can be several or more weeks. This type of consequence makes sense to me; it's not punitive (though it may feel as such, to those students who are not allowed on campus during an exam week), but they (or their parents) have made a personal choice about not receiving immunizations, while making a conscious choice to attend a public school, knowing the requirements beforehand.
I do believe that there should be consequences to individuals not following "standards of health" when living in a community. The consequences need to make sense, and be related to the intended behavior (here, getting a vaccine), and not be extraordinarily punitive.
Immunizations are not for individual health, but are for the community and for the health of the population. I compare rules or laws governing health behaviors in a similar way, whether it is for vaccinating your children (when they are attending public institutions) or wearing seat belts. Both are positive health behaviors in most cases. Seat belts can be risky at times, but *most of the time* save lives in car crashes. Immunizations can be risky at times, especially if there is a medical reason to not have a particular vaccine, but *most of the time, for most people* they prevent communicable diseases and infections in a population.
So, to answer the question directly: jail time and fines seem like unusual punishments. I don't think "scaring" people with harsh consequences will necessarily "scare" them into making a particular health decision, especially a decision as controversial as whether or not to vaccinate a child.