Oral polio vaccine AIDS hypothesis

Template:Short description Template:Use dmy dates {{#invoke:Labelled list hatnote|labelledList|Main article|Main articles|Main page|Main pages}} The Oral polio vaccine AIDS hypothesis (OPV AIDS) is a largely discredited hypothesis which argued the AIDS pandemic originated from live polio vaccines prepared in chimpanzee tissue cultures, accidentally contaminated with simian immunodeficiency virus and then administered to up to one million Africans between 1957 and 1960 in experimental mass vaccination campaigns.

Though a small number of experts initially thought this hypothesis was plausible, later data analyses in molecular biology and phylogenetic studies contradict the OPV AIDS hypothesis.<ref name=":1">Template:Cite journal</ref><ref name=Science>Template:Cite journal</ref><ref>Template:Cite journal</ref> Scientific consensus regards the hypothesis as lacking evidence<ref name=":1" /> or disproven.<ref name="cohen2" /><ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> A 2004 Nature article has described the hypothesis as "refuted".<ref name="worobey">Template:Cite journal</ref>Template:Non-primary source needed

Background: polio vaccines

Template:Details Two vaccines are used throughout the world to combat poliomyelitis. The first, a polio vaccine developed by Jonas Salk, is an inactivated poliovirus vaccine (IPV), consisting of a mixture of three wild, virulent strains of poliovirus, grown in a type of monkey kidney tissue culture (Vero cell line), and made noninfectious by formaldehyde treatment. The second vaccine, an oral polio vaccine (OPV), is a live-attenuated vaccine, produced by the passage of the virus through non-human cells at a sub-physiological temperature. The passage of virus produces mutations within the viral genome, and hinders the virus's ability to infect nervous tissue.<ref name=Kew_2005>Template:Cite journal</ref>

Both vaccines have been used for decades to induce immunity to polio, and to stop the spread of the infection. However, OPV has several advantages; because the vaccine is introduced in the gastrointestinal tract, the primary site of poliovirus infection and replication, it closely mimics a natural infection. OPV also provides long lasting immunity, and stimulates the production of polio neutralizing antibodies in the pharynx and gut.<ref name = Pearce>Template:Cite journal</ref> Hence, OPV not only prevents paralytic poliomyelitis, but also, when given in sufficient doses, can stop a threatening epidemic. Other benefits of OPV include ease of administration, low cost and suitability for mass vaccination campaigns.<ref name=Kew_2005/>

Oral polio vaccine

Oral polio vaccines were developed in the late 1950s by several groups, including those led by Albert Sabin, Hilary Koprowski and H. R. Cox.<ref name=Furesz>Template:Cite journal</ref> A poliovirus type 1 strain called SM was reported in 1954. A less virulent version of the SM strain was reported by Koprowski in 1957. The name of the vaccine strain was "CHAT" after "Charlton", the name of the child who was the donor of the precursor virus.<ref name=Plotkin>Template:Cite journal</ref> The Sabin, Koprowski and Cox vaccines were clinically tested in millions of individuals and found to be safe and effective. Because monkey trials found fewer side effects with the Sabin vaccine, in the early 1960s, the Sabin vaccine was licensed in the US and its use supported by the World Health Organization.<ref name="Furesz"/>

Between 1957 and 1960, Koprowski's vaccine was administered to roughly one million people in the Belgian territories, now the Democratic Republic of the Congo, Rwanda and Burundi.<ref name=Plotkin/> In 1960, Koprowski wrote in the British Medical Journal, "The Belgian Congo trials have enlarged considerably and ... more vaccination campaigns organized in several provinces of the Belgian Congo are raising the number of vaccinated individuals into the millions."(p. 90) Koprowski and his group also published a series of detailed reports on the vaccination of 76,000 children under the age of five (and European adults) in the area of Leopoldville (now Kinshasa) in Belgian Congo from 1958 to 1960; these reports begin with an overview,<ref name=Koprowski5>Template:Cite journal</ref> next a review of safety and efficacy,<ref name=Koproski2>Template:Cite journal</ref> then a 21-month follow-up and final report.<ref name=Koproski3>Template:Cite journal</ref>

Vaccine production

In the 1950s, before dangers inherent to the process were well controlled, seed stocks of vaccines were occasionally transported to distant regions, then standard tissue culture methods<ref name=Enders>Template:Cite book</ref><ref name=Rappaport>Template:Cite journal</ref><ref name=Melnick>Melnick, JL (1956) "Tissue culture methods for the cultivation of poliomyelitis and other viruses", in American Public Health Association, Diagnostic Procedures for Virus and Rickettsial Diseases 2nd ed., New York, pp. 97–151</ref> were used to amplify the virus at local production facilities. Biologic products, chiefly kidney cells for cultures and blood serum for media, were sometimes harvested from local primates and used in the production process if wild or captive populations of appropriate species were available.<ref name="Enders" /> In South Africa, African green monkey tissue was used to amplify the Sabin vaccine. In French West Africa and Equatorial Africa, baboons were used to amplify a vaccine from the Pasteur Institute. In Poland, the CHAT vaccine was amplified using Asian macaques.<ref name=PlotkinSA/>

Development of hypothesis

In 1987, historian-turned-activist Blaine Elswood contacted journalist Tom Curtis about a "bombshell story" on OPV and AIDS. Curtis published an article on the OPV AIDS hypothesis in Rolling Stone in 1992.<ref>Template:Cite news</ref> In response, viologist Hilary Koprowski, implicated in the article as being possibly involved in the early spread of AIDS, sued Rolling Stone and Tom Curtis for defamation. The magazine published a clarification which praised Koprowski and stated: Template:Quotation Rolling Stone was ordered to pay US$1 in damages whilst incurring around US$500,000 in legal fees for its own defense.<ref>Template:Cite journal</ref>

A few scientists, notably the evolutionary biologist W. D. Hamilton, thought the hypothesis required serious investigation, but they received little support from the scientific community.<ref name=lancet>Template:Cite journal</ref> For example, in 1996, Science refused to publish a letter Hamilton sent to it in which he replied to a 1992 Koprowski letter.<ref name=pol>Template:Cite journal</ref> Hamilton kept his position and said in 1999, "This theory, rather sadly, has gone from strength to strength. It's not proven by any means, but it's looking very strong."<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> Hamilton was also supportive of journalist Edward Hooper who detailed the hypothesis in his 1999 book, The River.<ref name=pol/> Hamilton wrote the foreword for the book and did two expeditions to Congo between December 1999 and January 2000 to collect evidences on the OPV hypothesis.<ref name=bozzi>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> None of the over 60 urine and faecal samples collected by Hamilton contained SIV.<ref name=lancet/> Still, Hamilton used his prestige within the Royal Society to promote a discussion meeting about the OPV hypothesis.<ref name=pol/> In this meeting, held six months after Hamilton's death, in September 2000,<ref name=bozzi/> Hooper further expanded on his allegations, although these claims were later rebutted by some of the scientists who were present at the meeting.<ref>Template:Cite journal</ref> In 2001, Hilary Koprowski responded by making a detailed rebuttal of the points made in the book, also in a talk to the Royal Society.<ref>Template:Cite journal</ref> In 2004, the Origin of Aids, a French TV documentary strongly supportive of the OPV hypothesis, appeared on several television stations around the world.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref><ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>

File:Cg-map.png

The Laboratoire Médical de Stanleyville was sited at the city now known as Kisangani.

In 2003, Hooper published additional statements that he believed supported his hypothesis in an article in the London Review of Books. These included accounts of an interview with Jacques Kanyama, a virology technician at the lab in Stanleyville (the Laboratoire Médical de Stanleyville (LMS)) responsible for testing the CHAT vaccine and performing the initial set of vaccinations, who was reported to have said that batches of CHAT had been produced on site by Paul Osterrieth. In addition, Philip Elebe, a microbiology technician, was claimed to have said that tissue cultures were being produced from Lindi chimpanzees. Osterrieth has denied these claims and stated that this work would not have been possible in this laboratory,<ref>Template:Cite journal</ref><ref>Template:Cite journal</ref><ref name=PlotkinSA/> stating that:

In his book, Hooper also stated that Gaston Ninane was involved in using chimpanzee cells to produce vaccine in Congo. Ninane responded to this allegation by stating that he could "categorically deny" ever having tried to make tissue cultures from chimpanzee cells.<ref name=Plotkin/> The people involved in vaccine production and distribution from America state that no vaccine was prepared locally in Congo and that only the CHAT vaccine from America was used. Barbara Cohen, the technician who was responsible for running the American laboratory that produced this vaccine stated:

Scientific investigation

In an August 1992 letter published in Science, Koprowski repudiated the OPV AIDS hypothesis, pointing to multiple errors of fact in its assertions.<ref>Template:Cite journal</ref> In October 1992, Science ran a story titled "Panel Nixes Congo Vaccine as AIDS source", describing the findings of an independent panel which found each proposed step in the OPV-AIDS hypothesis "problematic". The story concluded: Template:Quotation

The oldest confirmed sample of human tissue that shows the presence of HIV-1 is an archival sample of plasma collected from an anonymous donor in the city of Leopoldville, Belgian Congo (now Kinshasa, Democratic Republic of the Congo) in 1959 and was found with retrospective genetic analysis to be most closely related to subtype D strains. In 2008, partial HIV viral sequences were identified from a specimen of lymph node collected from an adult female, also in Kinshasa, in 1960. This specimen, named DRC60, was around 88% similar to ZR59, but was found to be most closely related to subtype A HIV-1 strains. These specimens are significant not only because they are the oldest specimens of the virus known to cause AIDS, but because they show that the virus already had an extensive amount of genetic diversity in 1960.<ref name=":0">Template:Cite journal</ref>

In 2000, the Royal Society held a meeting to discuss data on the origin of AIDS; the OPV AIDS hypothesis was a central topic of discussion. At this meeting, three independent labs released the results of tests on the remaining stocks of Koprowski's vaccine, which Edward Hooper had demanded in The River. The tests confirmed Koprowski's contention that his vaccine was made from monkey, rather than chimpanzee, kidney, and found no evidence of SIV or HIV contamination. Additional epidemiologic and phylogenetic data was presented at the conference which undermined other aspects of the OPV AIDS hypothesis. According to a report in Science,<ref name="cohen0">{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> Hooper "did not challenge the results; he simply dismissed them."

In 2001, three articles published in Nature examined various aspects of the OPV AIDS hypothesis, as did an article published in Science. In every case, the studies' findings argued strongly against any link between the polio vaccine and AIDS.<ref name="blancou">Template:Cite journal</ref><ref name="berry">Template:Cite journal</ref><ref>Template:Cite journal</ref><ref>Template:Cite journal</ref> The evidence cited included multiple independent studies that dated the introduction of HIV-1 to humans as occurring between 1915 and 1941, probably in the 1930s.<ref name=Korber>Template:Cite journal</ref><ref>Template:Cite journal</ref><ref>Template:Cite journal</ref> These results were confirmed by a later study using samples from the 1960s that also found that the epidemic began between 1908 and 1930,<ref name=":0" /><ref name="Reuters">{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> and a study that showed that although recombination amongst viruses makes dating less precise, it does not significantly bias estimates in either direction (it does not introduce a systematic error).<ref>Template:Cite journal</ref>

The author of one of the studies, evolutionary biologist Edward Holmes of Oxford University, commented in light of the new evidence: "Hooper's evidence was always flimsy, and now it's untenable. It's time to move on."<ref name="cohen2">Template:Cite journal</ref> An accompanying editorial in Nature concluded: Template:Quotation

The possibility that chimpanzees found near Kisangani in the Democratic Republic of Congo (formerly Stanleyville) were, indirectly, the true source of HIV-1 was directly addressed in a 2004 study published in Nature. Here, the authors found that while SIV was present in chimpanzees in the area, the strain of SIV infecting these chimpanzees was phylogenetically distinct from all strains of HIV, providing direct evidence that these particular chimps were not the source of HIV in humans.<ref name="worobey"/>

Current oral polio-vaccine campaign in Africa

Rumours that polio vaccines are unsafe disrupted the longstanding effort of the WHO and UN to achieve poliomyelitis eradication worldwide through use of the oral polio vaccine of Albert Sabin, which is thought to be safe and effective by virtually all medical authorities. If this long-term public-health goal could be achieved, poliomyelitis would follow smallpox as the second eradicated infectious human disease. The OPV AIDS hypothesis relates only to the historical origin of AIDS, and its proponents have accepted the safety of the modern polio vaccines, but rumors based on a misunderstanding of the hypothesis exist,<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref><ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> and those rumors are blamed in part for the recent failure to eliminate polio in Nigeria.<ref name=Jegede>Template:Cite journal</ref>

By 2003, cases of poliomyelitis had been reduced to just a small number in isolated regions of West Africa, with sporadic cases elsewhere. However, the disease has since resurged in Nigeria and in several other nations of Africa, which epidemiologists trace to refusals by certain local populations to allow their children to be administered the Sabin oral vaccine. The expressed concerns of local populations often relate to fears that the vaccine might induce sterility,<ref name=BBC>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> or that it is contaminated with HIV, based on claims made in The River.<ref name=Hooper1>Template:Cite news</ref> Since 2003, these fears have spread among some in the Muslim community, with Datti Ahmed, of the Supreme Council for Sharia in Nigeria stating that:

As evidence to the success of polio eradication efforts, the vaccine-derived polioviruses (cVDPVs) nowadays cause more cases of polio paralysis than the wild type virus itself in many places, such as the Congo.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> Polio has also resurged in areas of Pakistan, India and Bangladesh.<ref name=GPEI>Global Polio Eradication Initiative (2007) map of last six months of polio cases worldwide Wild Poliovirus Weekly Update initiative of WHO, CDC, UNICEF, Rotary International online Template:Webarchive</ref><ref name=BBC2>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>

See also

• AIDS origins opposed to scientific consensus
• AIDS origin
• SV40 A scientifically accepted case of a monkey virus contaminating polio vaccine – Inactivated poliovirus vaccine (IPV) only.
• Zoonosis

External links

• Where did HIV come from? Questions and Answers, from the United States Centers for Disease Control