See the allergy to vaccines is a medical reason to opt out, if there is a medical reason then I completely understand and agree with opting out but when the reason people opt out is because of fear of autism or some other myth spread around the antivac community it becomes quite worrisome... Where I live I have to fill out a form and be interviewed by the pharmacist before I can get the flu vaccine because they need to know for certain that it wont be detrimental.