Evidence Points Against Tainted Polio Vaccine as Cause of Rare Cancers

BETHESDA, Md—A large and growing body of data indicate that exposure to polio vaccines tainted with the simian virus SV40 “has not led to an outbreak of mesotheliomas, osteosarcomas, or ependyomas,” the NCI said.

Concern that people who received the original Salk and Sabin polio vaccines might have an increased risk of cancer first arose in 1960 when researchers found the virus had contaminated monkey kidney cells used to grow the vaccines. A recent study found traces of SV40 in human mesothelioma, osteosarcoma, and ependyoma tumors.

NCI scientists reported in 1997 that a 30-year follow-up of a large number of Americans exposed to the contaminated vaccines found no increase in these three cancers.