Simian virus 40, poliovirus vaccines, and human cancer: research progress versus media and public interests

From 1955 through early 1963, millions of people were inadvertently exposed to simian virus 40 (SV40) as a contaminant of poliovirus vaccines; the vir us had been present in the monkey kidney cultures used to prepare the vacci nes and had escaped detection. SV40 was discovered in 1960 and subsequently eliminated from poliovirus vaccines. This article reviews current knowledg e about SV40 and considers public responses to reports in the media. SV40 i s a potent tumour virus with broad tissue tropism that induces tumours in r odents and transforms cultured cells from many species. It is also an impor tant laboratory model for basic studies of molecular processes in eukaryoti c cells and mechanisms of neoplastic transformation. SV40 neutralizing anti bodies have been detected in individuals not exposed to contaminated poliov irus vaccines. There have been many reports of detection of SV40 DNA in hum an tumours, especially mesotheliomas, brain tumours and osteosarcomas; and DNA sequence analyses have ruled out the possibility that the viral DNA in tumours was due to laboratory contamination or that the virus had been misi dentified. However, additional studies are necessary to prove that SV40 is the cause of certain human cancers. A recently published review article eva luated the status of the field and received much media attention. The publi c response emphasized that there is great interest in the possibility of he alth risks today from vaccinations received in the past.