sv40 is a cancer causing virus that contaminated 1/3rd of all polio vaccines.
From wikipedia:
The discovery of SV40 revealed that between 1955 and 1963 around 90% of children and 60% of adults in the U.S. were inoculated with SV40-contaminated polio vaccines.
From wikipedia: The discovery of SV40 revealed that between 1955 and 1963 around 90% of children and 60% of adults in the U.S. were inoculated with SV40-contaminated polio vaccines.
Link to studies: https://scholar.google.com/scholar?hl=en&as_sdt=0%2C5&q=sv40...