Scientists rule out polio link to Aids

Scientists believe Aids jumped from chimps to humans

Scientists have dismissed claims that the Aids virus could have passed from chimpanzees to humans through a polio vaccine.

They said claims that the virus was included in a polio vaccine developed in Africa in the 1950s was nonsense.

Some researchers had put forward the idea that Aids jumped the species barrier after an experiment to prepare a vaccine was botched.

They suggested that infected tissue from chimpanzees had contaminated the vaccine.

Smokescreen claim

The theory was put forward in a book called The River by British journalist Edward Hooper which was published last year.

The facts of the matter are that there is a smokescreen around this

Edward Hooper, author of The River

However, research presented to a meeting of Aids experts at the Royal Society in London has shown that the vaccine did not contain chimpanzee DNA.

Mr Hooper had claimed that in the late 1950s, 400 chimpanzees were captured, killed and used to make one of the first oral polio vaccines in the world.

He believed that a team of scientists used the kidneys of chimpanzees with the SIV virus to develop the vaccine.

Chimpanzees host the SIV virus which is regarded as being similar to HIV.

The polio vaccine was given to at least one million people in the former Belgian Congo and what are now Rwanda and Burundi. The site of the 28 vaccination projects correlate closely with the earliest cases of HIV infection.

Monkey bite theory

However, tests carried out by Professor Claudio Basilico found no traces of chimpanzee DNA, SIV or HIV in the vaccine.

But Mr Hooper said the results did not disprove his theory. "The facts of the matter are that there is a smokescreen around this and the smokescreen is being put up by the people who made the vaccine," he said.

Aids experts called the London conference to discuss theories as to how the virus began to infect humans. The polio vaccine theory was one of a number being debated.

The researchers examined reports from three independent research laboratories into the origin of Aids.

New infections

Other theories suggest that Aids jumped to humans as a result of a bite or after a hunter became infected while capturing an ape, or preparing its flesh for eating.

Alternative explanations for the sudden emergence of Aids centre on deforestation bringing monkeys and apes into greater contact with humans, coupled with political and social upheavals.

There are currently more than 33 million people infected with HIV, 28 million of whom live in the developing world.

Up to 100 million people are projected to become infected with HIV over the next 10 years, 95% of them in developing countries.

Figures suggest that there is a new case of HIV infection every 11 seconds. Work is ongoing around the world to develop a vaccine but as yet there is no known cure.