1. There is no scientific study to determine whether vaccines have really prevented diseases. Rather disease graphs show vaccines have been introduced at the end of epidemics when the disease was already in its last stages. In case of Small Pox the vaccine actually caused a great spurt in the incidence of disease before public outcry led to its withdrawal.
2. There are no long-term studies on vaccine safety. Very short-term tests are carried out where the vaccinated subjects are checked against another group who are given another vaccine. Technically the tests should be carried out against a non-vaccinated group. No one really knows what protocols are followed at such industry based or industry sponsored trials.
3. There has never been any official attempt to compare a vaccinated population against a non- vaccinated population to know what vaccines are doing to the children and the society. Independent private studies (Dutch & German and the most recent KIGGS (Aug 2011) study involving 7724 children worldwide) have revealed that vaccinated children suffer much more than their un-vaccinated counterparts.
4. The child receives not one but many vaccines. There are practically no tests to determine the effects of multiple vaccines.