Vaccine Ingredients – SV40

Polio vaccines used in the late 1950s and early 1960s were contaminated with a virus called simian virus 40 (SV40) present in monkey kidney cells used to grow the vaccine. Subsequently, investigators found SV40 DNA in biopsy specimens obtained from patients with cancers such as mesothelioma (lung), osteosarcoma (bone) and non-Hodgkins lymphoma (lymph nodes). However, several facts should be noted:

  1. SV40 was present in cancers of people who either had or had not received the polio vaccines that were contaminated with SV40.
  2. SV40 has not been present in any vaccine since 1963. 
  3. People with cancers who were born after 1963, when SV40 was no longer a contaminant of the polio vaccine, were found to have evidence for SV40 in their cancerous cells. 
  4. Epidemiologic studies do not show an increased risk of cancers in those who received polio vaccine between 1955 and 1963.

Taken together, these findings do not support the hypothesis that SV40 virus contained in polio vaccines administered before 1963 caused cancers. 


Carroll-Pankhurst, C., E. A. Engels, H. D. Strickler, et al. “Thirty-five Year Mortality Following Receipt of SV40-Contaminated Polio Vaccine During the Neonatal Period.” British Journal of Cancer. 85 (2001): 1295–1297.

Engels, E. A., J. Chen, R. P. Viscidi, et al. “Poliovirus Vaccination During Pregnancy, Maternal Seroconversion to Simian Virus 40, and Risk of Childhood Cancer.” American Journal of Epidemiology. 160 (2004): 306–316.

Engels, E. A., H. A. Katki, N. M. Nielson, et al. “Cancer Incidence in Denmark Following Exposure to Poliovirus Vaccine Contaminated with Simian Virus 40.” Journal of the National Cancer Institute. 95 (2003): 532–539.

Engels, E. A., L. H. Rodman, M. Frisch, et al. “Childhood Exposure to Simian Virus 40-Contaminated Poliovirus Vaccine and Risk of AIDS-Associated Non-Hodgkin’s Lymphoma.” International Journal of Cancer.  106 (2003): 283–287.

Ferber D. Monkey virus links to cancer grow stronger. Science. 2002;296:1012-1015.

Ferber, D. “Creeping Consensus on SV40 and Polio Vaccine.” Science. 298 (2002): 725–727.

Fraumeni Jr., J. F., C. R. Stark, E. Gold, and M. L. Lepow. “Simian Virus 40 in Polio Vaccine: Follow-Up of Newborn Recipients.” Science.  167 (1970): 59–60.

Innis, M. D. “Oncogenesis and Poliomyelitis Vaccine.” Nature.  219 (1968): 972–973.

Mortimer, E. A., M. L. Lepow, E. Gold, et al. “Long-Term Follow-Up of Persons Inadvertently Inoculated with SV40 as Neonates.” New England Journal of Medicine.  305 (1981): 1517–1518.

Olin, P. and J. Giesecke. “Potential Exposure to SV40 in Polio Vaccines Used in Sweden during 1957: No Impact on Cancer Incidence Rates 1960 to 1993.” Development of Biological Standards.  94 (1998): 227–233.

Rollison, D. E. M., W. F. Page, H. Crawford, et al. “Case-Control Study of Cancer Among U.S. Army Veterans Exposed to Simian Virus 40-Contaminated Adenovirus Vaccine.” American Journal of Epidemiology. 160 (2004): 317–324.

Shah, K. and N. Nathanson. “Human Exposure to SV40: Review and Comment.” American Journal of Epidemiology  103 (1976): 1–12.

Shah, K. V., H. L. Ozer, H. S. Pond, et al. “SV40 Neutralizing Antibodies in Sera of U.S. Residents without History of Polio Immunization.” Nature.  231 (1971): 448–449.

Stenton, S. C. “Simian Virus 40 and Human Malignancy.” British Medical Journal  316 (1998): 877.

Strickler, H. D. and J. J. Goedert. “Exposure to SV40-Contaminated Poliovirus Vaccine and the Risk of Cancer: A Review of the Epidemiologic Evidence.” Development of Biological Standards.  94 (1998): 235–244.

Strickler, H. D., P. S. Rosenberg, S. S. Devesa, et al. “Contamination of Poliovirus Vaccines with Simian Virus 40 (1955–1963) and Subsequent Cancer Rates.” Journal of the American Medical Association.  279 (1998): 292–295.

Strickler, H. D., P. S. Rosenberg, S. S. Devesa, et al. “Contamination of Poliovirus Vaccine with SV40 and the Incidence of Medulloblastoma.” Medical and Pediatric Oncology.  32 (1999): 77–78.

Vilchez, R. A., A. S. Arrington, and J. S. Butel. “Cancer Incidence in Denmark Following Exposure to Poliovirus Vaccine Contaminated with Simian Virus 40.” Journal of the National Cancer Institute.  95 (2003): 1249.

Reviewed by Paul A. Offit, MD on April 28, 2020

Materials in this section are updated as new information and vaccines become available. The Vaccine Education Center staff regularly reviews materials for accuracy.

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