Eleven prominent AIDS researchers, primatologists and animal advocates urge vaccine developers not to inject chimpanzees with stem HIV that can cause diseases like AIDS in animals. In a letter published in Science tomorrow , they raise ethical and scientific objections to these experiences.
Until recently, chimpanzees have been considered poor models for testing vaccines, because HIV does not replicate well in animals or seem to make them sick. But that changed when researchers at the Yerkes Primate Research University Regional Centre Emory in Atlanta, Georgia, found a strain of HIV that causes a sharp decline in CD4 cells of animals and an increase of virus in their blood. In a study published in the June 19, 1998 Science , Norman Letvin Medical Center Beth Israel Deaconess Harvard in Boston noted that the strain might be useful for candidates Test vaccines, and many researchers on the AIDS agreed.
But not virologist Alfred Prince Of Blood Center of New York, who runs a chimpanzee colony in Liberia, and his colleague Linda Andrus. "The prospect of causing a rapidly progressive and fatal disease in this near-human species is abhorrent," they wrote in a letter to 18 December 1998 Science . A more acceptable to test vaccine candidates, they say, is whether it can prevent a virus to establish a chronic infection; where applicable, the disease does not occur. And several non-virulent strains seem to reproduce fairly well in chimpanzees to provide a realistic challenge, they wrote
In the new letter, Prince, Andrus, and nine others, including defender chimpanzees Jane Goodall, raise new objection .: the virulent strain of HIV may be too "hot". It destroys the immune system of a chimpanzee in a few weeks, while in men the same process generally takes years. This could "seriously compromise the vaccine effort against HIV" excluding vaccines do not protect against this strain, but but could be effective against wild-type HIV, they write.
But Patricia Fultz from the University of Alabama at Birmingham does not believe that the Emory HIV strains are too hot, noting that the infected animals have lived up to 4 years. and Letvin said that focusing only on the ability of a vaccine to ward off chronic infection rather than its effect on the disease process, may lead researchers to overlook a useful vaccine: "If we have a vaccine that can make people live decades longer, we need to know ".
0 Komentar