Origins of HIV and the AIDS Epidemic

September 11-12, 2000, The Royal Society, London, United Kingdom

Jonathan Weber, FRCP, FRCPath, FmedSci, Keith Alcorn, Medical Writer

In This Article

The Oral Polio Vaccine Hypothesis

The Royal Society meeting was originally envisaged as a forum for analysis of the hypothesis that an experimental OPV called CHAT was contaminated by SIVcpz, that the contaminated vaccine was fed to upwards of 1 million people in various parts of the Congo, Burundi, and Rwanda between 1957 and 1959, and that this vaccine transferred a low level of SIV into the human population.

The hypothesis has been raised by several investigators over the past 10 years, and has been elaborated most extensively by Edward Hooper, who was invited to present the evidence that supports his case. He was then answered by Dr. Stanley Plotkin and Dr. Hilary Koprowski, developers of the vaccine. In the interests of brevity, Hooper's allegations and the researchers' rebuttals are dealt with point by point.

Hooper argues that the attenuation of this particular polio virus was carried out by passaging it in a cell monolayer culture derived from chimpanzee kidney cells, rather than the macaque kidney cells used routinely for polio vaccine research at that time, and still used preferentially today. Plotkin says chimpanzee kidneys were never used because they were not a suitable substrate. It should be noted that there is no published or unpublished report from this era suggesting that chimp kidney cells were used for propagating polio virus.

Hooper argues that the development of the vaccine was carried out either at laboratories in the Congo or at the Wistar Institute in Philadelphia, Pennsylvania, and the Rega Institute in Antwerp, Belgium, and that there is inconsistent evidence about what substrate was used. All those directly involved in the development of CHAT say that the vaccine stock was propagated on macaque kidney cell monolayers and that chimp kidney cells were never used. Hooper's allegation that vaccine stocks were grown and purified in the Congo is not supported by testimony from any of the scientists involved.

Hooper says that he has signed statements from 2 individuals who worked at a chimp-holding facility called Lindi and a research station at Bujumbura in Rwanda that chimp kidneys were removed and shipped to other locations. In the case of Lindi camp, Hooper's witness said that staff members told him that the shipments of kidney were destined for the United States. However, this witness was indirectly reporting what had been said and had no first hand information.

Koprowski stated categorically that the chimps at Lindi were used only for challenge experiments to demonstrate the safety of CHAT OPV, and that the only organ shipments that took place from Lindi were the livers of primates used in hepatitis B experiments at the camp. Hooper has also suggested that a Polish researcher called Jezierski experimented with chimp kidney cells as a growth medium at a research station called Gabu Nioka in the north of Congo. Dr. Jan Destrymer says that chimp kidneys were not used at Gabu Nioka for vaccine development, based on evidence provided by Jezierski in papers published at the time.

Hooper claims that different batches of CHAT were prepared in different places but given the same number, so that the batch 10a/11 held by the Wistar Institute and supposedly used in the Congo may have been passaged further in the Congo in chimp kidney cells or another batch may have been manufactured in the Congo and given the same batch number. Plotkin describes this supposition as absurd and showed his original laboratory records for the batch, which show that lot 10a/11 was used in Sweden and New Jersey, as well as in Congo.


Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.
Post as: