The CDC has quickly removed a page from their website, which is now cached here, admitting that more than 98 million Americans received one or more doses of polio vaccine within an 8-year span when a proportion of the vaccine was contaminated with a cancer causing polyomavirus called SV40. It has been estimated that 10-30 million Americans could have received an SV40 contaminated dose of the vaccine.

SV40 is an abbreviation for Simian vacuolating virus 40 or Simian virus 40, a polyomavirus that is found in both monkeys and humans. Like other polyomaviruses, SV40 is a DNA virus that has been found to cause tumors and cancer. 

SV40 is believed to suppress the transcriptional properties of the tumor-suppressing genes in humans through the SV40 Large T-antigen andSV40 Small T-antigen. Mutated genes may contribute to uncontrolled cellular proliferation, leading to cancer.

Michele Carbone, Assistant Professor of Pathology at Loyola University in Chicago, has recently isolated fragments of the SV-40 virus in human bone cancers and in a lethal form of lung cancer called mesothelioma. He found SV-40 in 33% of the osteosarcoma bone cancers studied, in 40% of other bone cancers, and in 60% of the mesotheliomas lung cancers, writes Geraldo Fuentes.