Oral polio vaccine AIDS hypothesis

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. In response, virologist 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:

The editors of Rolling Stone wish to clarify that they never intended to suggest in the article that there is any scientific proof, nor do they know of any scientific proof, that Dr. Koprowski, an illustrious scientist, was in fact responsible for introducing AIDS to the human population or that he is the father of AIDS.

Rolling Stone was ordered to pay one US dollar in damages to Koprowski, whilst incurring around US$500,000 in legal fees for its own defense.

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. For example, in 1996, Science refused to publish a letter Hamilton sent to it in which he replied to a 1992 Koprowski letter. 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." Hamilton was also supportive of journalist Edward Hooper who detailed the hypothesis in his 1999 book, The River. 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. Hamilton argued that the Royal Society should hold a meeting about the OPV hypothesis. In this meeting, held six months after Hamilton's death, in September 2000, Hooper further expanded on his allegations, although these claims were later rebutted by some of the scientists who were present at the meeting. 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. In 2001, 60 urine and faecal samples collected by Hamilton were tested, although none contained SIV (although he did not necessarily expect them to).

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, stating that:

at no time did I ever attempt to make cell cultures from chimpanzee tissues. In addition, I wish to state categorically that no poliovaccine was ever produced or could have been produced in Stanleyville, since the facilities were totally inadequate for the production or control of poliovaccine.

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. 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:

At no time did I ever receive or work on chimpanzee kidneys, nor to my knowledge cells derived from chimpanzees. I never made, nor do I know of anyone in the lab who made polio vaccine in chimpanzee cells.

In 2004, the Origin of Aids, a French TV documentary strongly supportive of the OPV hypothesis, appeared on several television stations around the world.

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. 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:

...it can be stated with almost complete certainty that the large polio vaccine trial... was not the origin of AIDS.

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.

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, 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. 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. These results were confirmed by a later study using samples from the 1960s that also found that the epidemic began between 1908 and 1930, 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).

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." An accompanying editorial in Nature concluded:

The new data may not convince the hardened conspiracy theorist who thinks that contamination of OPV by chimpanzee virus was subsequently and deliberately covered up. But those of us who were formerly willing to give some credence to the OPV hypothesis will now consider that the matter has been laid to rest.

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.

Modern 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, and those rumors are blamed in part for the recent failure to eliminate polio in Nigeria.

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, or that it is contaminated with HIV, based on claims made in The River. 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:

We believe that modern-day Hitlers have deliberately adulterated the oral polio vaccines with anti-fertility drugs and viruses which are known to cause HIV and AIDS.