Re: There are two kinds of scientific studies...

"The rate of polio was in great decline before the vaccine was ever put on the market and now the only known cases of polio are vaccine related???"

This is a typical antivax falsehood.

The evidence is plain. If you look at polio statistics in the U.S., for example, the number of annual cases of paralytic polio varied in the years leading up to introduction of Salk's polio vaccine, ranging from 10-20,000 cases annually. After Salk's vaccine came into use in 1955, cases dropped off and continued falling (into the hundreds of cases per year) by the time Sabin's oral polio vaccine was licensed in 1962. Thereafter paralytic polio cases fell to a few per year and then none by the early 2000s. There is no other logical explanation for this success against polio, other than immunization.


http://www.post-polio.org/ir-usa.html


This success of vaccination against polio has been repeated around the world:

"Following the widespread use of poliovirus vaccine in the mid-1950s, the incidence of poliomyelitis declined dramatically in many industrialized countries. A global effort to eradicate polio began in 1988, led by the World Health Organization, UNICEF, and The Rotary Foundation.[68] These efforts have reduced the number of annual diagnosed cases by 99%; from an estimated 350,000 cases in 1988 to fewer than 2,000 cases in 2006.[69] Should eradication be successful it will represent only the second time mankind has ever completely eliminated a disease. The first such disease was smallpox, which was officially eradicated in 1979 (thanks to vaccination).[70] A number of eradication milestones have already been reached, and several regions of the world have been certified polio-free. The Americas were declared polio-free in 1994.[71] In 2000 polio was officially eradicated in 36 Western Pacific countries, including China and Australia.[72][73] Europe was declared polio-free in 2002.[74] Today, polio remains endemic in only four countries: Nigeria, India, Pakistan, and Afghanistan."


http://en.wikipedia.org/wiki/Polio


This is a tremendous success story for vaccination, one of many involving once-feared diseases.

If antivaxers could be persuaded to use reason instead of superstition, even more children's lives could be saved.