Greatmam Longitudinal studies to investigate whether there is a correlation between multiple vaccinations and an increase in chronic diseases such as asthma, lupus, MS, Crohn's disease, etc., etc.
Chronic disease isn't as dramatic and noticeable as acute infection but it is every bit as debilitating to the sufferer and if the health of the general population becomes more susceptible to chronic illness, this is an equally important issue.
In the meantime, the vast majority of parents will follow the current recommendations and have their children vaccinated. Those who have strong feelings on the matter should not be forced to get their children vaccinated.
I agree that with diseases causing very significant risk of damage or death, like polio, diphtheria, etc., parents should be strongly encouraged to have their children vaccinated.