Simian Virus 40 (SV40)

SV40 (simian virus) is the 40th virus identified by scientists studying monkeys. It has recently been identified in human mesothelioma cells. SV40 may work together (synergistically) with asbestos to cause mesothelioma. Polio vaccines administered to more than 90 million Americans during 1955 - 1961 were contaminated with SV40. During this time period polio vaccines were developed using monkeys to create the antibodies to protect people from polio. Both the Salk vaccine (administered by inoculation) and Sabin vaccine (administered orally) were contaminated with SV40 until at least the early 1960s. Researchers and vaccine manufacturers were aware of the SV40 contamination but did not take steps to remove the virus from the vaccines. However the implications of these facts are not totally understood and further research will be needed to clarify the link between malignant mesothelioma and a viral etiology.