The US National Institutes of Health has announced that it will retire its remaining research chimpanzees, Nature reports.
In 2011, the Institute of Medicine issued a report that said that though chimps had been an important animal model in the past, technological advances had made most chimp-based research unnecessary. The NIH accepted the IOM's recommendations and sent most of its chimps, about 300, into retirement at sanctuaries.
However, NIH retained about 50 of its research chimps for studies that met certain criteria outlined by the IOM report.
NIH now says that these remaining chimps will be moved to sanctuaries once there's available space.
"I think this is the natural next step of what has been a very thoughtful five-year process of trying to come to terms with the benefits and risks of trying to perform research with these very special animals," NIH Director Francis Collins tells Nature. "We reached a point where in that five years the need for research has essentially shrunk to zero." Collins has recently been a target of an animal rights group.
He notes that NIH had only received one application since 2013 to use chimps in research and that that application was withdrawn.
Animal welfare groups welcomed the NIH decision, the AP notes. The Humane Society of the United States' Kathleen Conlee says her group is "overjoyed."
But some scientists question the decision to hold no chimps in reserve for research. "Given NIH's primary mission to protect public health, it seems surprising," Frankie Trull from the Foundation for Biomedical Research tells Nature.
Others note that conservation research may be hampered.
The NIH is also developing a strategy to handle chimps the agency supports, but does not own.