Apparently,
the "polio vaccine causes cancer" zombie meme has been reanimated by the antivaccination cult. Lacking evidence for their beliefs, retreading old debunked memes is their standard operating procedure.
The interesting thing about social media (Facebook, Twitter, blogs, Google, reddit) is that it's fairly easy to push pseudoscientific beliefs. The first problem is that many people read the headlines, and never the underlying discussion. If it can be said in 140 characters, or a misleading infographic, many individuals will share that across the internet as a "fact". So, if you see an claim that "Polio vaccines infected 98 million Americans with a cancer virus," many people will immediately see that an accept it without much criticism.
Of course, this leads to a second problem. To refute this claim takes a lot more than 140 characters. The refutation is often complex, nuanced and highly scientific, and may take 2000 words or more to blast the claim into orbit. It's highly emotional to claim a vaccine can cause cancer. On the other hand, to say it is not isn't emotional–it's coldly logical. And takes a lot of words.
And the third problem is that is that social media fallacies have multiple lives, so when someone reads one of these memes a year from now, they think "yeah, this is great information", and pass it along as if it's the Truth. Killing zombie memes are just as difficult as killing zombies in real life, or at least, on a TV show. Debunking these zombie memes is a full-time job. And, once it's been debunked, we move back to the first problem again, again, and again.
Thus, the best we skeptics can do is keep discrediting these social media fables and tall tales, and move along to refuting the next one in line. I wrote about this topic over a year ago, but now I have to refresh it, just to make sure someone who Googles "polio vaccine cancer" has my article near the top of their list of Google hits.
The Myth
According to the antivaccination cult, the central story is that the CDC admitted that 98 million Americans received the polio vaccine during an 8-year span when it was contaminated with a cancer virus. Other websites essentially repeat the same nonsense. And it's in the lyrics of a rap song (seriously, the stuff people send me continues to amaze). The first article is authored by Dave Mihalovic, who is a naturopathic doctor (typically someone who eschews science-based medicine in favor of pseudoscience like homeopathy and acupuncture). He also claims to be a “vaccine researcher.”
If Mihalovic is a vaccine researcher, he has published exactly zero PubMed-indexed articles about vaccines. He actually hasn't published anything about any medical science anywhere. His claim to being a vaccine researcher rings rather hollow.
What Mihalovic probably means is his research included a few hours on Google and thinks he’s now as smart as anyone who actually has a bachelor’s and doctoral degree in immunology, virology, biochemistry or some other biomedical science that matters to real vaccine research. Of course, a real "vaccine researcher" has a decade or two or three of real scientific research in a real world class laboratory.
Mihalovic is as much a vaccine researcher as I am an Oscar winning screenwriter. I can say that I write screenplays. I can claim that I am Steven Spielberg's best buddy. But it would take you about 14 nanoseconds to find that there is no evidence of my being a screenwriter, and you’d just think I was nuts. Mihalovic, of course, thinks he's as brilliant as a real scientific vaccine researcher, but his credibility as one is about as suspect as my bonafides as a screenwriter. Approximately 0.
Nevertheless, let's get back to what these vaccine deniers are claiming:
- Polio vaccines were contaminated with the SV40 virus (known as simian virus 40, a polyomavirus that is found in both monkeys and humans),
- SV40 causes cancer,
- And, the CDC admits that 98 million Americans are at significant risk of SV40 infection and thus cancer.
So are you now scared? If you are older than 50, according to Mihalovic and his gang of sycophants (and one wannabe rap songwriter), you are carrying a virus that will give you some cancer. And this antivaccination zombie meme keeps coming back to life, making even more scary.
The Real Science
As I said, responding to the myth of "polio vaccine causes cancer" takes much more time. As a scientific skeptic, with, I hope, above-average critical thinking skills, I can smash the myth into tiny little pieces.
The fact is that of the three parts of the myth mentioned in the previous section, on the first one is partially true, and the rest are complete nonsense. None are supported by real scientific or historical evidence. But like most pseudoscience, they are based on some tiny piece of science, but then overblown with logical fallacies, misleading terminology, and outright untruths.
Here is the evidence-based story, using real scientific and historical information, which anyone can read themselves to get the accurate story:
- The groundbreaking and lifesaving polio vaccines, developed by Jonas Salk (injected, inactivated virus, vaccine) and Albert Sabin (oral, live virus, vaccine). Immunization against polio went back and forth between the two versions, though since the early 1980's, the USA use the Salk version of the vaccine almost exclusively. The vaccines were developed in the early 1950's, and were produced using VERO green monkey kidney cell lines. Typically, viruses used in vaccines need to be "grown" in a cell line, because viruses cannot replicate themselves without hijacking an infected cell. I know that some of the antivaccine crowd think that viruses are grown magically, and you can just grab a handful of them, throw them in a blender and make a vaccine.
- In 1959, microbiologist Maurice Hilleman found a monkey virus in both vaccines—it was the 40th simian virus (SV) to be discovered by scientists, so it was given the moniker of SV40 (creativity in naming viruses isn't important even today). Back in the 1950's, we didn't have the technology that we do now to screen for contaminants in the growth medium, so the SV40 virus had contaminated the VERO line well before the beginning of production of vaccines. Not all of the VERO cells in culture were contaminated, just some of them.
- Salk’s inactivated virus vaccine, which was treated with formaldehyde (only a tiny amount remains in the vaccine, so let's not spend time arguing about "danger" of formaldehyde in vaccines), had very small amounts of the SV40 virus. On the other hand, Sabin’s live oral vaccine was heavily contaminated with SV40, because there was no treatment made to the vaccine to inactivate the polio virus.
- Worried about the potential effects the virus could have on humans, researchers injected it into hamsters, finding that nearly all of them developed massive cancerous tumors. But, as I've said on numerous occasions, primary research should be examined carefully before accepting that it has any type of applicability to human health.
- Upon further review of the initial studies, it was observed hamsters that ingested SV40 instead of being injected with it didn’t develop any cancers. In other words, Sabin’s live oral vaccine (which actually had a higher burden of SV40 than the injected, inactivated virus Salk vaccine) did not cause any cancer. Additional studies showed that children who were given Sabin’s vaccine did not develop antibodies to SV40; apparently, the virus quickly and safely passed through the child's digestive system, never causing an SV40 infection.
- On the other hand, Salk’s vaccine, which contained very little SV40, but was given by injection, and there was evidence that some of these children might have been infected with SV40. However, recent studies have shown no credible evidence (here, here, here and here) that those children who received SV40 contaminated vaccines had an increased incidence of cancer as unvaccinated children. No plausible evidence suggests that SV40 has ever caused cancer in humans. A meta review of published research from the 1960's to 2004 showed no evidence that supported any causal link between SV40 and any cancer. A review of cancers thought to be most associated with SV40 found no evidence to support causality.
- And polio vaccines have been SV40 free since 1963 in most advanced countries, although Soviet bloc vaccines were contaminated until the 1980's.
Predictably, the information spread by the "polio causes cancer" articles pushed by the vaccine deniers are wrong on so many levels. First, not all polio vaccines were contaminated, and the SV40 virus in the oral vaccine merely passes through the digestive tract without causing an infection. SV40, as shown in so many published articles, does not cause cancer in humans. If it does, it's at such a low rate that it's impossible to detect unless we check tens of millions of patients. Finally, the number of "98 million" is an incredible scary, but ultimately inaccurate number (a tactic employed the antivaccination crowd whenever it suits their needs to establish dangers of vaccines).
The facts are before the SV40 virus was removed from the vaccine, around 98 million children got one of the two forms of the polio vaccine. However, eliminating those who got the oral vaccine, which, as we have established, did not infect children with the SV40 virus, approximately 10-30 million Americans were immunized with the Salk vaccine that contained the SV40. Potentially, only those 10-30 million Americans are at actual risk of contracting the SV40 virus; however, given the low levels (very low levels) of actual SV40 contamination of the vaccines, those numbers probably vastly overstate the SV40 risk.lio-vaccine-1950s.jpg" alt="polio-vaccine-1950s" width="340" height="439" />
The TL;DR Review
- The SV40 virus contaminated some polio vaccine cultures.
- Not all polio vaccines from the 1950's through 1963 were contaminated by the SV40 virus.
- Those who took the oral vaccine just passed the SV40 virus through their digestive tract.
- Certainly, not 98 million children were infected with SV40.
- SV40 was eliminated from polio vaccine production after 1963, so the SV40 risk is currently 0.
- SV40 is associated with lots of cancers, but there is no evidence that it causes cancer. None.
- Let's remember the most important point–polio vaccines have saved and will save many many lives. And we have irrefutable evidence for it.
The problem with man in the antivaccination movement is that if you just looked at the headlines for those articles, you're probably terribly concerned that giving the polio vaccine to your children puts them at risk of cancers. Or that somehow worse information about vaccines is being suppressed by the CDC, FDA, and Illuminati. But the problem is that the CDC and FDA have been open about this story for 50 years, and have invested boatloads of money into researching it. And there's almost nothing there.
Key citations:
- Carbone M, Pass HI, Miele L, Bocchetta M. New developments about the association of SV40 with human mesothelioma. Oncogene. 2003 Aug 11;22(33):5173-80. Review. PubMed PMID: 12910254.
- Dang-Tan T, Mahmud SM, Puntoni R, Franco EL.Polio vaccines, Simian Virus 40, and human cancer: the epidemiologic evidence for a causal association. Oncogene. 2004 Aug 23;23(38):6535-40. Review. PubMed PMID: 15322523.
- Eddy BE, Borman GS, Berkeley WH, Young RD. Tumors induced in hamsters by injection of rhesus monkey kidney cell extracts. Proc Soc Exp Biol Med. 1961 May;107:191-7. PubMed PMID: 13725644.
- Engels EA, Chen J, Hartge P, Cerhan JR, Davis S, Severson RK, Cozen W, Viscidi RP. Antibody responses to simian virus 40 T antigen: a case-control study of non-Hodgkin lymphoma. Cancer Epidemiol Biomarkers Prev. 2005 Feb;14(2):521-4. PubMed PMID: 15734981. Impact factor: 4.559
- Engels EA, Chen J, Viscidi RP, Shah KV, Daniel RW, Chatterjee N, Klebanoff MA. Poliovirus vaccination during pregnancy, maternal seroconversion to simian virus 40, and risk of childhood cancer. Am J Epidemiol. 2004 Aug 15;160(4):306-16. PubMed PMID: 15286015. Impact factor: 4.780
- Engels EA, Katki HA, Nielsen NM, Winther JF, Hjalgrim H, Gjerris F, Rosenberg PS, Frisch M. Cancer incidence in Denmark following exposure to poliovirus vaccine contaminated with simian virus 40. J Natl Cancer Inst. 2003 Apr 2;95(7):532-9. PubMed PMID: 12671021. Impact factor: 14.336
- Engels EA, Viscidi RP, Galloway DA, Carter JJ, Cerhan JR, Davis S, Cozen W, Severson RK, de Sanjose S, Colt JS, Hartge P. Case-control study of simian virus 40 and non-Hodgkin lymphoma in the United States. J Natl Cancer Inst. 2004 Sep 15;96(18):1368-74. PubMed PMID: 15367569. Impact factor: 14.336
- Hilleman MR. Discovery of simian virus 40 (SV40) and its relationship to poliomyelitis virus vaccines. Dev Biol Stand. 1998;94:183-90. Review. PubMed PMID: 9776239.
- Kimman TG, Boot H. The polio eradication effort has been a great success--let's finish it and replace it with something even better. Lancet Infect Dis. 2006 Oct;6(10):675-8. PubMed PMID: 17008176.