Exhibit 112 · Agency web page
Historical Vaccine Safety Concerns: Simian virus 40
From 1955 to 1963, an estimated 10-30% of polio vaccines administered in the US were contaminated with simian virus 40 (SV40).
CDC states that from 1955 to 1963 an estimated 10–30% of polio vaccines administered in the United States were contaminated with SV40, mostly inactivated vaccine but also oral vaccine. It states that after the contamination was discovered the government set testing requirements to verify that all new lots were free of SV40, that most studies are reassuring and find no causal association with cancer, and that no vaccine used today contains SV40.
- Source
- Centers for Disease Control and Prevention
- Date
- Current page, accessed 2026
- Quoted from
- CDC 'Historical Vaccine Safety Concerns', section 'Simian Virus 40 (SV40): 1955 - 1963', paragraph 1
- Grade
- Primary record
- Document
- https://www.cdc.gov/vaccine-safety/historical-concerns/
- Accessed
- 2026-11-09
- Cited by
- Findings citing this exhibit