Adventitious agents in viral vaccines: Lessons learned from 4 case studies
“The four cases are: a) SV40 in polio vaccines; b) bacteriophage in measles and polio vaccines; c) reverse transcriptase in measles and mumps vaccines; and d) porcine circovirus and porcine circovirus DNA sequences in rotavirus vaccines.”
? Association between SV40 and non-Hodgkin’s lymphoma.
“Millions of people worldwide were inadvertently exposed to live simian virus 40 (SV40) between 1955 and 1963 through immunization with SV40-contaminated polio vaccines. Although the prevalence of SV40 infections in humans is not known, numerous studies suggest that SV40 is a pathogen resident in the human population today. SV40 is a potent DNA tumor virus that is known to induce primary brain cancers, bone cancers, mesotheliomas, and lymphomas in laboratory animals.”
Cancer risk associated with simian virus 40 contaminated polio vaccine.
Don’t ignore the risk of vaccine contamination
“Sir, Your News and Opinion articles about alleged contamination of vaccines should serve as a warning against over-optimism.
These articles highlight the failure to show any evidence for contamination of Wistar Institute polio vaccine stocks by human and simian immunodeficiency viruses (HIV/SIV), and you appeal for a truce. But — although Edward Hooper is quoted as saying that “vaccine samples released did not include any from batches prepared for use in Africa” — lymphocytes have been detected in other polio vaccines. Half of the vervet monkeys in Southern Africa are SIV positive; these animals were used for preparing early polio vaccines.
Considering the many millions of vaccine doses prepared in primary vervet monkey kidney cultures over a 30-year period, it is inconceivable that some SIV did not contaminate many cultures. By the same yardstick, simian virus 40 (SV40) contaminated millions of doses of poliovirus vaccine until the animals were screened for this tumour virus.
Edward Hooper and others surely do not intend to undermine the polio vaccine efforts. What is needed is a new awareness of the need for caution — remembering the example of BSE — in view of the current impetus towards xenotransplantation and the accompanying danger of contamination. Our aim should be to improve our vaccines, not to undermine public confidence in them.”
Human and animal vaccine contaminations.
“However, since vaccine preparation involves the use of materials of biological origin, vaccines are subject to contamination by micro-organisms. In fact, vaccine contamination has occurred; a historical example of vaccine contamination, for example, can be found in the early days of development of the smallpox vaccine. The introduction of new techniques of vaccine virus production on cell cultures has lead to safer vaccines, but has not completely removed the risk of virus contamination. There are several examples of vaccine contamination, for example, contamination of human vaccines against poliomyelitis by SV40 virus from the use of monkey primary renal cells. Several veterinary vaccines have been contaminated by pestiviruses from foetal calf serum. These incidents have lead industry to change certain practices and regulatory authorities to develop more stringent and detailed requirements. But the increasing number of target species for vaccines, the diversity of the origin of biological materials and the extremely high number of known and unknown viruses and their constant evolution represent a challenge to vaccine producers and regulatory authorities.”
? Oral polio vaccine and human cancer: a reassessment of SV40 as a contaminant based upon legal documents.
“The confirmation of the removal by one drug manufacturer, Lederle, has been made public at an international symposium in January 1997, where its representatives stated that all of Lederle’s seeds had been tested and screened to assure that it was free from SV40 virus. However, in litigation involving the Lederle oral polio vaccine, the manufacturer’s internal documents failed to reveal such removal in all of the seeds. The absence of confirmatory testing of the seeds, as well as testimony of a Lederle manager, indicate that this claim of removal of SV40 and the testing for SV40 in all the seeds cannot be fully substantiated. These legal documents and testimonyc indicate that the scientific community should not be content with prior assumptions that SV40 could not have been in the oral polio vaccine.”
? Polio, hepatitis B and AIDS: an integrative theory on a possible vaccine induced pandemic.
“The hypothesis that simian virus 40 (SV40) infected polio vaccines may be linked to the evolution of acquired immunodeficiency disorder (AIDS), and certain cancers, has been advanced. Most recently, investigators discussed the likelihood of gene-reshuffling following SV40 infection as a precursor to acquired immune dysfunction. Findings of recent SV40 infections in four children born after 1982 suggest infections were transmitted vertically along gene lines. Earlier observations proved activation of a retrovirus gene by a hepatitis B virus (HBV) protein. This paper proposes a new integrative theory on the origin of AIDS. It advances the possibility of genetic recombinations with oncogene activation by HBV involving simian viruses that likely infected polio vaccinated blood donors to the initial hepatitis B (HB) vaccine trials conducted on gay men in New York City and Ugandan Blacks in the early to mid-1970s. The socio-economic and even military ramifications associated with this politically challenging thesis are discussed.”
Full article here-
Polio vaccines and the origin of AIDS.
“In particular, it is now known that the early polio vaccines were contaminated with at least one monkey virus, SV40. The transfer of monkey viruses to man via contaminated vaccines is particularly relevant to the acquired immunodeficiency syndrome (AIDS), since the causative agent of AIDS, human immunodeficiency virus (HIV), is thought to be derived from a simian precursor virus. Furthermore, human infection with this virus appears to be a relatively recent event. We hypothesize that the AIDS pandemic may have originated with a contaminated polio vaccine that was administered to inhabitants of Equatorial Africa from 1957 to 1959. The mechanism of evolution of HIV from this vaccine remains to be determined.”
Simian cytomegalovirus and contamination of oral poliovirus vaccines.
“In the 1950s the use of primary rhesus macaque kidney cultures to propagate poliovirus for vaccine production led to the contamination of vaccines with simian virus 40 (SV40). African green monkey kidney (AGMK) cultures free of SV40 were used as an alternative cell substrate for vaccine manufacture. In this study we evaluate oral poliovirus seeds, vaccine bulks and vaccines themselves for the presence of a common contaminant of AGMK cultures, simian cytomegalovirus (SCMV). Using sensitive polymerase chain reaction (PCR) techniques, nearly half of the samples analysed were found to be contaminated with SCMV sequences. However, vaccine bulks, positive by PCR for SCMV failed to show any evidence of infectious virus in these studies. One poliovirus vaccine and one seed, propagated on rhesus macaque kidney cultures were found to be positive for the rhesus monkey CMV by PCR.”
Some oral poliovirus vaccines were contaminated with infectious SV40 after 1961.
“Some polio vaccines prepared from 1954 to 1961 were contaminated with infectious SV40. It has been assumed that all polio vaccines were SV40 free in the United States after 1961 and in other countries after 1962. Following a WHO requirement that was prompted by the detection of SV40 in some human tumors, we conducted a multilaboratory study to test for SV40 polio vaccines prepared after 1961. Vaccine samples from 13 countries and the WHO seed were initially tested by PCR. The possible presence of intact and/or infectious SV40 DNA in PCR-positive samples was tested by transfection and infection of permissive CV-1 cells. All results were verified by immunohistochemistry, cloning, and sequencing. All the vaccines were SV40 free, except for vaccines from a major eastern European manufacturer that contained infectious SV40. We determined that the procedure used by this manufacturer to inactivate SV40 in oral poliovirus vaccine seed stocks based on heat inactivation in the presence of MgCl2 did not completely inactivate SV40. These SV40-contaminated vaccines were produced from early 1960s to about 1978 and were used throughout the world. Our findings underscore the potential risks of using primary monkey cells for preparing poliovirus vaccines, because of the possible contamination with SV40 or other monkey viruses, and emphasize the importance of using well-characterized cell substrates that are free from adventitious agents. Moreover, our results indicate possible geographic differences in SV40 exposure and offer a possible explanation for the different percentage of SV40-positive tumors detected in some laboratories.”
[SV40 as a possible cofactor in the etiopathogenesis of mesothelioma and other human tumors].
“Simian virus 40 (SV40) has been introduced into the human population with contaminated polio vaccines between 1955 and 1963. Previous research conducted by southern blot hybridization and recent analysis by PCR have shown the presence of SW0 sequences in human brain tumors, mesotheliomas and osteosarcomas as well as in normal tissues such as blood and sperm fluids. SV40 RNA and T antigen were detected in the same tissues. All the samples were coinfected by BK Virus (BKV), suggesting that BKV may have a helper function for SV40 replication in human cells. The presence of SV40 in human tumors suggests that the virus may be a cofactor in the etiopathogenesis of human neoplasia. In addition, blood and semen may represent the vectors for transmission of SV40 by horizontal infection in the human population.”