Panel: Limit medical experiments on chimps

— -- Science should halt medical experiments on chimpanzees, the closest cousins to humans in the animal world, except perhaps for preventive vaccines for Hepatitis C and some drug therapies where there are no better alternatives, an expert panel concluded Thursday.

The Institute of Medicine report, headed by bioethicist Jeffrey Kahn of Johns Hopkins University in Baltimore, comes after years of disagreement between animal rights advocates and medical researchers over the 937 research chimps held at five institutions nationwide.

For decades, U.S. medical researchers have relied upon chimps to test drugs, perform medical experiments such as vaccine safety and conduct behavioral tests on the species most closely related to humanity. Most notably, chimp studies led to advances in understanding malaria and in identifying Hepatitis C, a disease that chronically infects more than 130 million people worldwide and can lead to liver cancer, according to the World Health Organization.

However, efforts to breed research chimps for NASA's 1960s' space race and for HIV research, a bust because chimps are immune to the disease, left a glut of chimps at test facilities, leading to a moratorium on breeding in 1995. NIH now supports 110 projects involving chimps.

As a cost-cutting measure, the National Institutes of Health last year proposed shipping 186 chimps retired from research to a Texas facility where they could become medical experiment subjects. The proposed move angered animal rights advocates such as chimp researcher Jane Goodall, and led NIH to request the report from the congressionally chartered institute.

"Most current use of chimpanzees for biomedical research is unnecessary," the panel concludes after reviewing medical and behavioral problems among chimps subjected to experiments. The 12-expert panel suggested few ongoing drug tests justified chimp experiments, largely because other animals or human tests worked just as well, and divided over preventive hepatitis vaccine experiments on chimps.

"The bar is very high," Kahn said, at a briefing on the report, on whether any future invasive medical experiments, where chimps are infected or experimentally vaccinated, should be conducted.

"If chimpanzees were not available for research, science would still go forward," says infectious disease expert Stephen Barthold of the University of California, Davis, who reviewed the report but was not on the panel. "The report emphasized that the current need for chimpanzees in research is minimal or non-existent …."

The 2005 mapping of the chimp genome shows the ape species diverged from human ancestry within the last 7 million years and can be considered about 99% genetically similar to people. This close relatedness of the chimps not only makes it "a uniquely valuable species for certain types of research, but also demand(s) a greater justification for their use in research," the panel said.

For that reason, chimpanzee medical research needs to basically be limited to life-threatening human diseases for which there are no alternative animals to study, the panel concluded. "The very same reason why chimpanzees are biomedically important, they are so like us, offers excellent moral reasons against their use," says primate researcher Frans de Waal of Emory University in Atlanta. The panel report said behavioral research on chimps, such as testing for intelligence or cooperation (which de Waal conducts), should only be allowed in cases where the same research could be performed ethically on people, as well.

The panel did not consider the cost of maintaining chimps, which can almost live as long as people, but both Barthold and de Waal suggest that expense also argues against continuing chimp experiments. Gabon is the only other country that permits chimp experiments. "The real challenge to NIH in this era of budget austerity will be the cost of maintaining even limited captive colonies," Barthold says by e-mail, on the off chance some future disease will arise demanding medical experiments on chimps.