Between 1954 and 1963, millions of doses of contaminated polio vaccine were administered to school children throughout the U.S. The offending contaminant was a virus known as simian virus 40, or SV40. While the exact numbers can never be known, it’s estimated that between 10 and 30 million people received vaccines containing the virus.
The SV40 virus is routinely found in rhesus monkeys. It has also been found in some human cancers, according to the Centers for Disease Control.
How the @*%# Did This Happen?
In the 1950s, rhesus monkey kidney cells–some infected with SV40–were used to manufacture polio vaccines. Since the virus was not discovered until 1960, no one was looking for it prior to that time. (Not that the testing methods of the day could’ve detected it anyway). The formaldehyde used to sterilize vaccines was not sufficient to kill SV40, allowing millions of doses to become infected.
All this is irrelevant, though, because once SV40 virus was discovered in the polio vax, it remained on the market for years. Even worse, the newer oral polio vaccine used through the 1990s might have also been contaminated.
In 1997, the old Salk polio vaccines were dusted off and analyzed. Lo and behold, they contained a new virulent strain of SV40. This slow-growing strain has been detected in human cancers including mesothelioma, osteosarcoma and non-Hodgkin’s lymphoma.
What Are the Implications?
As primates with similar DNA, humans and monkeys share many common diseases. Like SIV, the monkey version of the HIV virus, SV40 does not cause disease…in monkeys. In hamsters, the SV40 cancer link is well established. Even more disturbing: SV40 has been found in the exact same types of cancer in humans.
Cancer is a complex disease whose causes can be difficult to tease out. In most cases, it results from a mysterious interplay between genetics, lifestyle & luck. Many viruses (“oncoviruses“) are known to cause cancer in humans, including Epstein-Barr, HIV, HPV and Hepatitis B.
As the saying goes, correlation does not equal causation. Simply finding SV40 in a tumor does not prove that it caused the disease. However, understanding why it’s there could offer valuable clues about the processes that cause cells to become cancerous in the first place.
Could It Happen Again?
Without a magic 8 ball, it’s impossible to know. We could wake up tomorrow to headlines about a novel virus in today’s vaccines. (One major theory purports that HIV was enabled to jump species due to unclean vaccination procedures, but that’s another story). Considering the SV40 polio vaccine legacy, it would not be surprising.
Just don’t expect an apology from the CDC, WHO or other government organizations. They have a history of downplaying the risks of vaccines to prevent mass hysteria and re-emergence of deadly diseases like polio. A valid concern, but one that must be balanced with medical integrity, ethics and informed consent.