vaccines
The CDC has admitted that between 1955-1963 over 98 million Americans received one or more doses of a polio shot which was contaminated with a cancer-causing virus called Simian vacuolating virus 40 (SV40). The CDC quickly took down the page, along with Google, but the site was luckily cached and saved to symbolize this grand admission.

CDC polio vaccine
To further confirm this unbelievable admission, Assistant Professor of Pathology at Loyola University in Chicago Dr. Michele Carbone has been able to independently verify the presence of the SV40 virus in tissue and bone samples from patients who died during that era. He found that 33% of the samples with osteosarcoma bone cancers, 40% of other bone cancers, and 60% of the mesothelioma's lung cancers all contained this obscure virus. This leaves the postulation that upwards of 10-30 million actually contracted and were adversely affected by this virus, to be deadly accurate.