HEALTH: World Polio Vaccine Supply is HIV-Free, Says WHO

By Gustavo Capdevila Reprint | | Print |

Gustavo Capdevila

GENEVA, Sep 13 2000 (IPS) - The World Health Organisation (WHO) assures the poliomyelitis vaccines currently being used around the world are free of the virus that causes AIDS.

The international institution has made the announcement in hopes of dispelling rumours that AIDS was spread via polio vaccines developed in Africa in the 1950s, presumed to have been contaminated with HIV, which causes the syndrome.

Mothers and communities in general can confidently utilise the current vaccines because there is no danger of accidental infection, said José Esparza, co-ordinator of the HIV Vaccine Initiative, a joint project of the WHO and the United Nations Programme on HIV/AIDS (UNAIDS).

For the WHO, the clarification of the situation is crucial because the agency is currently involved in a campaign to completely eradicate polio from the planet by 2005, and the few remaining pockets of the disease are located primarily in Africa and Asia.

The vaccines used have been extensively tested and there is no possibility of HIV infection through polio vaccines or any other related medications, stressed Esparza, a Venezuelan-born medical researcher.

Over the last two decades, AIDS has become the most lethal of epidemics, claiming the lives of 20 million people. Currently, nearly 34 million are infected with HIV. Of that total, some 28 million live in developing countries, most in Africa.

The theory that the AIDS epidemic was accidentally unleashed in Africa in the 1950s – during experiments conducted by researchers from the industrialised North – resurfaced this week in London in discussions among AIDS experts.

The hypothesis had also attracted worldwide attention with the publication in 1999 of “The River: A Journey to the Source of HIV/AIDS,” by British journalist Edward Hooper. He wrote that HIV crossed the species barrier, from chimpanzees to humans, through an experimental oral vaccine to fight polio, developed in Africa.

The vaccine, prepared by Belgian and US researchers, was used to inoculate nearly one million people in the former Belgian Congo and the current territories of Rwanda and Burundi.

Hooper asserted that chimp kidneys were utilised in the preparation of the experimental vaccine. The scientific community generally agrees that the AIDS-causing virus originated in this anthropoid species.

The first scientific study to establish the close relationship between human HIV and the virus that infects the subspecies of chimpanzees in western Africa was published by a group of researchers led by oncologist Beatrice Hahn, of the US University of Alabama, Birmingham.

The transference of the disease occurred through the handling of the animals, which were hunted for food in that region. In the task of butchering the chimp carcasses, humans were exposed to the animals’ blood, explained Esparza.

Infection from the blood was likely if the people handling the carcasses had any open wounds on their hands.

The surviving members of the Belgian-US team of scientists denied using chimpanzees in preparing the polio vaccine itself, asserting the animals were used only to test its effectiveness.

Analyses of the polio vaccines used in the 1950s, which were kept in frozen storage at the Wistar Institute in the US city of Philadelphia, showed no sign of contamination with HIV or the related chimpanzee virus.

In those tests, the latest techniques were used to check for the existence of chimp cells or their DNA, and the results were negative, Esparza said.

The conclusion of the Royal Society meeting in London established that there is no scientific evidence or written report that indicates chimpanzees were used in preparing the vaccines distributed in Africa in the 1950s.

“These findings are consistent with other epidemiological, biological and virological evidence, and indicate that Mr. Hopper’s hypothesis cannot be substantiated,” says the WHO.

The vaccines now being used in the anti-polio campaign are produced using cells from the kidneys of Asian monkeys, which do not carry the AIDS virus, Esparza pointed out.

With these vaccines, the WHO global campaign to eradicate polio has been able to reduce the total number of cases by 95 percent since it began 12 years ago. The world is well on its way to making the disease disappear, says the WHO.