About 300 chimps will be retired over the next two years, or possibly longer, according to Cathy Spraetz, director of Chimp Haven in Louisiana, the nation's only federally-approved chimp sanctuary.
"It's fabulous. We're overjoyed," said Spraetz.
The NIH's decision follows a CNN investigation
in February that found the agency had fallen woefully behind in retiring chimpanzees. Only six of 310 research chimps promised retirement in June 2013 had been allowed to leave government research facilities, and the agency had no timetable for when it would retire the rest of the animals.
Many of the chimps had been intentionally infected with diseases such as hepatitis or HIV -- or both -- for the sake of medical science, and dozens had died waiting to be retired to Chimp Haven, which has acres of forest where the chimps can roam.
In emails to CNN last year, NIH spokeswoman Amanda Fine had said the delay in retiring chimps was due, in part, to the selection of 50 animals that would be kept out of retirement in case they were needed for "critical research" in the future. Selecting those chimps, Fine said, could "require a period of several years."
On Wednesday, Dr. Francis Collins, director of the NIH, said in a statement
he had reassessed that need. "We reached a point where ... the need for research has essentially shrunk to zero," Collins said in an interview with Nature
Spraetz thinks it was personally important to Collins to make this change. "He wanted this to be something he could leave his mark on. When he leaves he wants to know that all the chimps have been retired. He wanted that to be part of his legacy."
In February, Chris Abee, who runs the research laboratory at the Keeling Center at MD Anderson Cancer Center
in Texas, said he wanted to keep the 150 government chimps he had then and that they could be helpful in saving human lives.
"When the chimpanzees are not on study, this is a sanctuary for them," he said at the time, noting that at any given time, most of the chimps are not involved in studies.
Officials for the Keeling Center did not respond to CNN's request for comment about the NIH's new actions.
Spraetz said it is unclear who will pay to expand Chimp Haven to accommodate the hundreds of new chimps. She said her organization is launching a capital campaign in early 2016, but the government might also pay for part of it. The first set of chimps could arrive by the end of the year, she said.