This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Rizzo, P. Articles by Carbone, M. Search for Related Content PubMed PubMed Citation Articles by Rizzo, P. Articles by Carbone, M.

Unique Strains of SV40 in Commercial Poliovaccines from 1955 Not Readily Identifiable with Current Testing for SV40 Infection¹

Loyola University Medical Center, Cardinal Bernardin Cancer Center, Cancer Immunology Program, Department of Pathology, Maywood, Illinois 60153

SV40 was first identified as a contaminant of poliovaccines used from 1955 until 1963. Recently, SV40 has been detected in several human tumors. The virus detected in human tumors often contained only one 72-bp enhancer in the regulatory region, in contrast to the SV40 originally isolated from poliovaccines, which contained two 72-bp enhancers. The origin of viruses with one 72-bp enhancer in humans was unknown, because it was thought that these viruses were not present in poliovaccines. It was also thought that all poliovaccine vials produced from 1955 until 1963 had been discarded, thus the possibility that one 72-bp virions contaminated those vials could not be tested. We unexpectedly obtained what appear to be the last available vials of poliovaccine produced in 1955. In these vials, we detected and sequenced SV40 containing only one 72-bp enhancer in the regulatory region. The tissue culture cytopathic test currently used in the United States to screen oral poliovaccines was designed to detect rapidly proliferating SV40 virions containing two 72-bp enhancers. We found that this test is not sensitive enough to detect low amounts of the slow-replicating SV40 virions containing one 72-bp enhancer. This virus was easily detected in the same cells by immunostaining and PCR. Twelve current vials of poliovaccines tested uniformly negative for SV40, suggesting that the precaution of preparing poliovaccines from kidneys obtained from monkeys bred in isolated colonies prevented SV40 contamination. Our data demonstrate that humans were exposed to SV40 viruses with both one 72-bp enhancer and two 72-bp enhancers SV40 through contaminated vaccines. Our data also suggest that instead of cytopathic tests, immunohistochemical and/or molecular studies should be used to screen poliovaccines for SV40 to completely eliminate the risk of occasional contamination.

This article has been cited by other articles:

				R. Cutrone, J. Lednicky, G. Dunn, P. Rizzo, M. Bocchetta, K. Chumakov, P. Minor, and M. Carbone Some Oral Poliovirus Vaccines Were Contaminated with Infectious SV40 after 1961 Cancer Res., November 15, 2005; 65(22): 10273 - 10279. [Abstract] [Full Text] [PDF]

				Z. H. Forsman, J. A. Lednicky, G. E. Fox, R. C. Willson, Z. S. White, S. J. Halvorson, C. Wong, A. M. Lewis Jr., and J. S. Butel Phylogenetic Analysis of Polyomavirus Simian Virus 40 from Monkeys and Humans Reveals Genetic Variation J. Virol., September 1, 2004; 78(17): 9306 - 9316. [Abstract] [Full Text] [PDF]