Correction: Earlier versions of this story incorrectly stated the number of NIH-funded chimpanzee studies that would fail to meet new standards. This number has been corrected.

Chimps Doll and Alvin have been used in biomedical research and are now free. (Linda Koebner/CHIMP HAVEN)

The National Institutes of Health has placed a temporary moratorium on new studies using chimpanzees, it announced Thursday in response to a report that marks nearly all medical research on the great apes as scientifically unjustified.

“Effective immediately, NIH will not issue any new awards for chimpanzee research” as the agency puts in a place a committee to review research proposals, NIH Director Francis Collins said during a press briefing.

Chimpanzee research that does not meet rules established by the report will be phased out, Collins said. He estimated that about half of the 37 current NIH-funded chimp studies would not rise to standards proposed in Thursday’s report from the Institute of Medicine, part of the National Academy of Sciences.

The congressionally mandated study concluded that any future studies using the great apes need to clear a “very high bar,” said Jeffrey Kahn, a bioethicist at Johns Hopkins University who chaired the report committee.

“Fewer kinds of studies will be justified based on the criteria that we set out,” Kahn said. “We’re on a trajectory of a diminishing number of chimps necessary for research.”

The report did not endorse an outright ban on chimp research but instead outlined restrictive rules for using the apes.

Chimpanzees’ similarity to humans in intelligence and emotional awareness implies “a moral cost and ethical issues” when mankind’s closest evolutionary cousin is kept captive for invasive medical research, Kahn said.

Chimpanzees are not needed for research on HIV/AIDS, cancer or nearly any other type of disease, the IOM found. After surveying the past decade of medical chimp research, the report committee concluded that only one disease might warrant further research with apes: the development of a vaccine to prevent hepatitis C.

But even that conclusion was contentious. Half of the 12-member committee of medical experts thought that hepatitis C vaccine research could move forward without testing new vaccines on chimps.

Some 3.2 million Americans have the hepatitis C virus, which attacks the liver and often proves fatal. No preventive vaccine exists.

Since 2001, the National Institutes of Health has funded 110 studies with chimps, the IOM report found, including 44 studies for hepatitis, nine for HIV/AIDS, 11 for brain research and 13 projects on genetics.

Kahn said many of those studies would not be justified under the new rules, which state that chimpanzee research should be allowed only if such work is vital to the public health and cannot be performed any other way.

For nonmedical research, such as studies of behavior and cognition, chimpanzees should be used only if they provide “otherwise unattainable insights” and only if they are “acquiescent,” or willing to participate, the report stated.

Collins said NIH will deploy these strict criteria to scrutinize current and proposed chimp research.

Research chimps should remain available in case a new disease emerges that can only be studied in the animals, the IOM report recommended. In response, Collins said, the new NIH committee will assess how many chimpanzees should be kept “in case some world emergency should arise.”

Some 937 chimpanzees live in five facilities in the United States. The NIH owns or otherwise funds about 600 of the chimps, many of which are older and retired from research.

The non-NIH chimps are owned by the research institutes and made available to drug companies. The new NIH rules do not apply to those animals.

Some 340 NIH and non-NIH chimps live at the New Iberia Research Center in Louisiana. The center’s director, Thomas Rowell, expressed concerns about the new rules disallowing certain medical tests on the NIH chimps that the Food and Drug Administration might require as it evaluates potential drugs.

Rowell said he will seek clarification on that and other points during a Dec. 20 conference call with the IOM committee.

Another 153 NIH-owned chimps reside at the Texas Biomedical Research Institute in San Antonio. In a statement, the institute’s chief scientific officer, John L. VandeBerg, welcomed the new scrutiny.

“We look forward to the [NIH committee’s] assessment of the current and proposed research projects at our primate center,” he said.

The European Union banned chimpanzee research last year, leaving the United States and the small African nation of Gabon as the only countries with chimpanzee medical research programs. At drug companies, chimp research is waning with the emergence of lower-cost, higher-tech alternatives.

Animal-rights groups applauded the report and the NIH decision.

It’s “wonderful news,” said David Pearle, a spokesman for the People for the Ethical Treatment of Animals.

Wayne Pacelle, president and chief executive of the Humane Society of the United States, said in a statement that the IOM report points to “only one reasonable conclusion: it’s time to end the use of chimps in harmful, invasive research.”

“We think they got it about 90 percent right,” said John Pippin, director of academic affairs for the Physicians Committee for Responsible Medicine, which opposes chimp research. “The unspoken message is that the era of chimp research for human diseases is ending.”

The issue exploded last December after the NIH began moving older chimps from a retirement facility in New Mexico to an active research laboratory in Texas. After a public outcry, Sens. Jeff Bingaman (D-N.M.), Tom Harkin (D-Iowa) and Tom Udall (D-N.M.) asked the IOM to look into the matter.

Congress could end the debate by passing a proposed bill, the Great Ape Protection and Cost Savings Act, which would ban all chimpanzee research.

However, the bill, sponsored by Rep. Roscoe G. Bartlett (R-Md.), has been stalled for three years and appears far from a vote.