'Scientists started Aids epidemic'

Professor Hilary Koprowski's vaccine was used on thousands

A polio vaccine using tissue from primates could have been behind the leap made by the human immunodeficiency virus - HIV - from apes and moneys to humans, a new book claims.

The idea is not novel - a version of the theory was published in the early 1990s and knocked down - but the new book sets out the facts in more detail.

Called The River, it offers evidence that scientists' good intentions may have led to the virus gaining a hold on the human population.

Samples of the vaccine under suspicion still exist, and the head of the World Health Organization's (WHO) polio eradication programme has called for it to be tested, if only to put the theory to rest once and for all.

The theory also alarms those who believe the future of medicine is likely to include xenotransplantation, where organs from one animal - such as a pig - are placed in a human.

Gaining strength

Professor Bill Hamilton, of Oxford University's department of zoology, said: "This theory, rather sadly, has gone from strength to strength. It's not proven by any means, but it's looking very strong."

Professor Bill Hamilton: "Strong theory"

Dr Hilary Koprowski, a doctor in Philadelphia produced the vaccine in the 1950s when the race was on to prevent a disease that was as feared in its time as cancer or Aids now.

Edward Hooper, author of The River, points to a correlation between the sites of mass inoculations using Dr Koprowski's vaccine in the late 1950s and the first recorded cases of Aids in the 1960s.

Three parts of the Democratic Republic of Congo - at the time the Belgian Congo and subsequently Zaire - were particularly affected.

These were Rouzizi Valley, Lubudi and Leopoldville - where the first case of the disease was detected in a blood sample from 1959.

Circumstantial evidence

Dr Harry Hull, head of the WHO's polio eradication programme, was sceptical.

Dr Harry Hull: Sceptical

"This theory requires first that the vaccine be contaminated, that the conditions be right for the propagation of the virus and that it then go into children and grow," he said.

"It also does not make sense in that there were other children who received this vaccine who didn't contract it - so the question is why would it just be the children in the Congo and not elsewhere?"

He called for remaining samples of the vaccine to be examined to settle the question.

Mr Hooper stood by his theory, although he admitted he could not be certain it was the truth.

"It is still a hypothesis, but I consider that the circumstantial evidence that is put forward now is compelling," he said.

The wrong monkey

Critics of the theory say that the virus originated in chimpanzees, but Dr Koprowski has always said the primate material used in the vaccine came from Asiatic monkeys.

Edward Hooper: "Compelling evidence"

However, Mr Hooper said he had evidence to the contrary.

"I have individual testimony from three or four people that these chimps were used, the kidneys were excised from these chimps and sent back not only to Philadelphia where Koprowski was working but also to Belgium where they were used in cell cultures."

But Professor Preston Marks, a senior scientist at the Aaron Diamond Aids Research Centre, in New Orleans, has yet to be convinced.

"The first problem is that we have an oral vaccine that would not transmit SIV (the chimpanzee form of HIV)," he said.

"That's compounded by the fact that these viruses have existed in monkeys for millions of years, and the virus never crossed over."

Eating chimps

In that time, monkeys and chimpanzees had been hunted for food, he said.

"One's mucous membranes and mouth would be exposed to the blood and tissue of these chimpanzees and monkeys while chopping and processing them for the table.

"There has to be something else, something additional, besides oral exposure to minimal amounts of SIV."

The WHO stressed that all polio vaccines currently in use are rigorously screened and are safe.