The US National Institutes of Health (NIH) is temporarily barring federally funded experiments on chimpanzees as it reviews a report that concluded most research done on the primates is not necessary.
The report by a committee of the Institute of Medicine (IOM) determined most tests on chimpanzees are not ethically justified.
Jeffrey Kahn, the committee chair, said the panel decided that "research use of animals that are so closely related to humans should not proceed unless it offers insights not possible with other animal models and unless it is of sufficient scientific or health value to offset the moral costs."
"We found very few cases that satisfy these criteria," he added.
The report still left the door open for research on fatal or debilitating human diseases that cannot be performed another way.
The committee also deemed acceptable ongoing studies on monoclonal antibody therapies, comparative genomics and non-invasive studies of social and behavioral factors that affect the development, prevention or treatment of disease.