Fact Check: Polio Vaccine Worked And The CDC Did NOT Admit 98 Million Americans Received Vaccine Contaminated With Cancer Agent

Fact Check

  • by: Alexis Tereszcuk
Fact Check: Polio Vaccine Worked And The CDC Did NOT Admit 98 Million Americans Received Vaccine Contaminated With Cancer Agent History Errors

Did the CDC admit 98 million Americans received the polio vaccine between 1955 and 1963 when it was "contaminated with cancer-causing virus 'SV 40'"? No, that mis-states what the public health agency said and over-states the number exposed to SV40. At most, millions of people were given a vaccine that was contaminated with "SV 40" but there is no evidence it caused cancer in the people who had received it who subsequently were diagnosed with cancer. In reports shared with the public, the U.S. Centers for Disease Control and Prevention explained 10% to 30% of 98 million polio vaccines administered those years were contaminated with "simian virus 40 (SV40)," and declared there was "no causal association between receipt of SV40-contaminated polio vaccine and development of cancer."

The claim appeared a post (archived here) published on Instagram on December 2, 2020. It opened:

Did vaccines get rid of polio?🤔 The answer is NO!🚫💉

Here is what the post looked like on Instagram:

The Rizza Islam post, which includes a video, said:

The lie i hear so often as a counterargument is that vaccines "eradicated polio" when that is absolutely INCORRECT! Between 1955 - 1963 CDC Admits 98 Million Americans Received the Polio Vaccine In An 8-Year Span When It Was Contaminated With the Cancer -causing Virus "SV 40" or Simian vacuolating 40.

There is no peer-reviewed basis for claims that any factor other than vaccination eliminated the disease, which caused more than 15,000 new cases of paralysis each year in the early 1950s.

In a fact sheet on polio elimination, the U.S. Centers for Disease Control says:

Following introduction of vaccines--specifically, trivalent inactivated poliovirus vaccine (IPV) in 1955 and trivalent oral poliovirus vaccine (OPV) in 1963--the number of polio cases fell rapidly to less than 100 in the 1960s and fewer than 10 in the 1970s.

Even America's most skeptical and scientifically advanced enemy accepted the data on polio vaccine and a polio vaccine program was a rare example of Cold War-era cooperation between the U.S. and the U.S.S.R. Soviet scientists travelled to the U.S. to meet and work with U.S. vaccinologists and launched a program to defeat polio, which was a growing problem in Russia and other Soviet states at that time.

While the vaccine did eradicate polio, it is true that millions of people were given a polio vaccine that included simian virus 40 (SV40) -- the virus came from monkey kidney cells "which were used to grow poliovirus for vaccine production (SV40 can be found in wild monkey populations, as well as humans)," Science Feedback reported. When the traces of the SV40 were found in the vaccinations, the government required it be removed from future vaccines.

The details about the polio vaccine and the contamination is not a new revelation and is not something the CDC recently admitted. There have been published reports about this since 1963, including in 2001 and 2004. Snopes.com debunked a similar claim in 2015 and in 2019 Science Feedback said, "The claim that SV40 is a cancer-causing virus in humans is not adequately supported by scientific evidence."

The CDC website dedicated a section to "Historical Vaccine Safety Concerns," and explained the history behind the polio vaccine and the contamination:

From 1955 to 1963, an estimated 10-30% of polio vaccines administered in the US were contaminated with simian virus 40 (SV40). The virus came from monkey kidney cell cultures used to make polio vaccines at that time. Most of the contamination was in the inactivated polio vaccine (IPV), but it was also found in oral polio vaccine (OPV). After the contamination was discovered, the U.S. government established testing requirements to verify that all new lots of polio vaccines were free of SV40.
Because of research done with SV40 in animal models, there has been some concern that the virus could cause cancer in humans. However, most studies looking at the relationship between SV40 and cancers are reassuring, finding no causal association between receipt of SV40-contaminated polio vaccine and development of cancer.
No vaccines used today contain SV40 virus."


The claim is that 98 million people were given the contaminated vaccine. The CDC provided a link to a report published on the National Center for Biotechnology Information titled, "Immunization Safety Review: SV40 Contamination of Polio Vaccine and Cancer," which noted the number of people given the polio vaccination from 1955 to 1963.

IPV administered between 1955 and 1963 to about 98 million children and adults is assumed to be the primary source of human exposure to SV40 in the United States."

The CDC says the amount is 10% to 30% of the total vaccines given, so between 10 million to 30 million people, not 98 million were given the contaminated vaccine.

Science Feedback shared an expert opinion about the polio vaccination from Angéline Rouers, a research fellow, Singapore Immunology Network

Overall, it is accurate to say that SV40-contaminated poliovirus vaccines were used to vaccinate people, however, this issue was addressed and resolved as soon as it was raised. None of the existing data allow us to link SV40 contained in the vaccine to cancer development later."

Children's Hospital of Philadelphia published a fact sheet titled, Vaccine Ingredients - SV40, stating SV40 did not cause cancer in the people who received the polio vaccination.

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:
SV40 was present in cancers of people who either had or had not received the polio vaccines that were contaminated with SV40.
SV40 has not been present in any vaccine since 1963.
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.
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."

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Lead Stories is working with the CoronaVirusFacts/DatosCoronaVirus Alliance, a coalition of more than 100 fact-checkers who are fighting misinformation related to the COVID-19 pandemic. Learn more about the alliance here.


  Alexis Tereszcuk

Alexis Tereszcuk is a writer and fact checker at Lead Stories and an award-winning journalist who spent over a decade breaking hard news and celebrity scoop with RadarOnline and Us Weekly.

As the Entertainment Editor, she investigated Hollywood stories and conducted interviews with A-list celebrities and reality stars.  

Alexis’ crime reporting earned her spots as a contributor on the Nancy Grace show, CNN, Fox News and Entertainment Tonight, among others.

Read more about or contact Alexis Tereszcuk

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