For the record regarding Polio that everyone is so vocal on. Between 1923 and 1953, before the Salk vaccine was introduced, polio declined on its own by 47% and 55% respectivly. (International Mortality Stats 1981)
When national vaccine campaigns were initiated in the 50's, the number of reported cases of polio were significantly greater than before the vaccinations - and almost doubled in the US alone. (Source - US government statistics)
In 1959 Bernice Eddy discovered vaccines being administered contained an infectious agent, capable of causing cancer. (you can look up SV40 on your own, we all have google)
Experts estimate that between 1954 and 1963, 30 million to 100 million americans were exposed to SV40 through ill-conceived polio eradication campains.
In other parts of the world, new and highly virulet strains of polio caused by mutations and recombinations within the oral polio vaccine are inducing unprecedented outbreaks of paralysis and death.
In the US the only cases of polio since the 70's have been FROM the vaccine itself.