From 1955 to 1963, hundreds of millions of people worldwide — in North and South America, Canada, Europe, Asia and Africa — received polio vaccines that may have been contaminated with simian virus 40 (SV40), a monkey virus.1 The video above is a decade old, but it succinctly summarizes the serious consequences that can occur from vaccine contamination — consequences that may not be realized until many years later.

In the video, Dr. John Bergsagel, then a pediatric oncologist, looks at laboratory slides of tumors taken from children who died of extremely rare brain cancers. When SV40-like DNA sequences were detected in them, he said, “I almost fell out of my chair. I was very surprised.”

The finding, published in The New England Journal of Medicine in 1992, revealed that half the choroid plexus tumors and most of the ependymomas studied contained a segment of T-antigen gene related to SV40.

“These results suggest that SV40 or a closely related virus may have an etiologic role in the development of these neoplasms during childhood,” they wrote2 — and this was only the beginning of findings linking monkey virus-contaminated polio vaccines to cancer.

How a Monkey Virus Ended up in Polio Vaccines

During the 1950s, the inactivated polio vaccine created by Jonas Salk was made using rhesus monkeys that were infected with SV40. As explained in a 2004 perspective published in The Lancet:3

“When Salk developed his vaccine, instead of using human tissues, as did the scientists who won a Nobel Prize for first growing poliovirus in tissue culture, he used minced-up rhesus macaque monkey kidneys, which were remarkably efficient poliovirus factories.

Those who sought to supplant Salk’s formaldehyde-inactivated vaccine with live, attenuated oral vaccine also used monkey kidney cultures. Despite a manufacturing problem that, at best, left six children who received the vaccine paralyzed in the arm, and despite concerns about wild simian viruses, Salk’s shots were declared safe and effective after 1954 field trials.

The next year, after grudging approval by skeptical government regulators, free Salk shots were made available throughout the USA. By 1960, scientists and vaccine manufacturers knew that monkey kidneys were sewers of simian viruses.”

The late Bernice Eddy, a researcher at the National Institutes of Health, conducted a study in 1959, injecting hamsters with the rhesus monkey kidney substrate used to make the vaccines. The majority of them developed tumors.4

“Eddy’s superiors tried to keep the discovery quiet, but Eddy presented her data at a cancer conference in New York. She was eventually demoted, and lost her laboratory,” The Atlantic reported,5 but soon after researchers with Merck pharmaceutical company identified the cancer-causing virus in rhesus monkey kidney cells, naming it SV406 because it was the 40th monkey virus discovered.

According to Barbara Loe Fisher, co-founder and president of the National Vaccine Information Center (NVIC), in a presentation before the U.S. House of Representatives in 2003:7

“Sadly, the American people were not told the truth about this in 1960. The SV40 contaminated stocks of Salk polio vaccine were never withdrawn from the market but continued to be given to American children until early 1963 with full knowledge of federal health agencies.

Between 1955 and early 1963, nearly 100 million American children had been given polio vaccine contaminated with the monkey virus, SV40.”

SV40’s Cancer Link

In animal studies, SV40 has been linked to a number of cancers, including mesotheliomas, lymphomas, brain and bone tumors and sarcomas.8 Such tumors in humans have also been found to contain SV40 DNA and proteins. Brain tumors and mesotheliomas appear to be the most common tumors associated with SV40, with some studies showing a positivity rate of up to 60%.

While there wasn’t an “epidemic” of cancers that followed the widespread administration of vaccines contaminated with SV40, which suggests the virus alone may not be causing the cancers, researchers noted, “it seems possible that SV40 may act as a cofactor in the pathogenesis of some tumors.”9

As further reported in Oncogene, at least three independent scientific panels agreed “there is compelling evidence that SV40 is present in some human cancers and that SV40 could contribute to the pathogenesis of some of them.”10

It was also revealed that, in Finland where no SV40-contaminated polio vaccine was used, researchers did not find any SV40-like DNA in frozen tumor tissues from Finnish mesothelioma patients.

The results suggest that the SV40-like DNA sequences detected in other mesothelioma tissue did come from contaminated polio vaccines, though, “It is a matter of speculation whether the absence of SV40 infection has contributed to the relatively low incidence of mesothelioma in Finland.”11

In 2002, meanwhile, The Lancet published evidence showing SV40 is significantly associated with some types of Non-Hodgkin lymphoma after detecting it in 42% of Non-Hodgkin lymphomas tested.12 And in a 2004 review of the then-available evidence, it’s noted:13

“Persuasive evidence now indicates that SV40 is causing infections in humans today and represents an emerging pathogen.

A meta-analysis of molecular, pathological, and clinical data from 1,793 cancer patients indicates that there is a significant excess risk of SV40 associated with human primary brain cancers, primary bone cancers, malignant mesothelioma, and non-Hodgkin’s lymphoma.”

It’s often claimed via the media and even by some prominent health organizations that the link between SV40 from vaccines and cancer has been debunked as a myth, but in 2002 the Institute of Medicine released a report that found “evidence is inadequate to accept or reject a causal relationship between SV40-containing polio vaccines and cancer,” adding:14

“… biological evidence is of moderate strength that SV40 exposure could lead to cancer in humans under natural conditions … biological evidence is of moderate strength that SV40 exposure from the polio vaccine is related to SV40 infection in humans.”

Is SV40 Spreading Through Human Populations?

Controversy still remains over the SV40-contamianted vaccines, including whether the monkey virus is still spreading among humans. There is evidence, for starters, that SV40-contaminated live oral polio vaccines (OPV) continued to be used for many years after SV40 contamination was discovered, including until 1978 in the former USSR and until 1999 in Italy.15

In fact, in 2005 researchers with Loyola University in Chicago conducted a study to test for SV40 in OPV prepared after 1961. They tested vaccine samples from 13 countries, revealing that OPV from “a major eastern European manufacturer” produced from the early 1960s to about 1978 contained infectious SV40:16

“Our findings underscore the potential risks of using primary monkey cells for preparing poliovirus vaccines, because of the possible contamination with SV40 or other monkey viruses, and emphasize the importance of using well-characterized cell substrates that are free from adventitious agents.

Moreover, our results indicate possible geographic differences in SV40 exposure and offer a possible explanation for the different percentage of SV40-positive tumors detected in some laboratories.”

Once exposed to the SV40 virus via a contaminated vaccine, it’s also possible that it has spread among humans via other methods. The monkey virus was found to spread for weeks in children’s stools following vaccination with SV40-contaminated vaccines, for instance,17 which suggests SV40 may replicate in gastrointestinal cells and could be spread via a fecal-oral route.

DNA sequences from SV40 have been found in a wide range of tissues among those vaccinated with SV40-contaminated vaccine, including pituitary tissues and leukocytes from organ and blood donors, as well as blood samples. “These data cumulatively demonstrate that SV40 is circulating in the human population,” researchers wrote in Frontiers in Oncology.18