Simian Virus 40

Peer Review Status: Holden Comprehensive Cancer Center, Cancer Information Service
First Published: March 2003
Last Revised: April 2003

In 1961, scientists showed that SV 40 produced changes in human cells and caused cancer in lab animals. The issue of SV40 came into the news again a few years ago when researchers, using extremely sensitive biological methods, found traces of SV40 in rare tumors, such as mesothelioma (cancer of the lining of the lung or abdomen), osteosarcoma (bone cancer) and a type of childhood brain tumor.

In the past 40 years, there have been many research studies to see if exposure to SV40 through polio vaccines has caused health problems in humans, including cancer. Epidemiology (the science that studies how often a disease occurs) studies in the United States and Europe have not found any increase in the cancer risk in those who were likely to have been given the virus containing vaccine. These studies include the following:

• A long-term study in Sweden published in 1998 followed 700,000 people who received SV40 contaminated vaccine as children.
• A German study that followed 886,000 persons for 22 years. These people received the contaminated vaccine as infants.
• A U.S. study of 1,000 persons who received the contaminated vaccine in the first week of their lives were followed for 20 years.

The National Cancer Institute has more plans to continue the evaluation of possible links between SV40 and cancer in humans.