Until now, that path had been hard to find.
Beginning in the 1970s, the blood center used the chimps for research on a hepatitis B vaccine, which ended in 2006. The animals were owned by the government of Liberia.
The center supported the chimps until the spring of 2015, when it cut off funds. Officials said negotiations with the Liberian government had not been productive.
At the time, Victoria O’Neill, a spokeswoman for the blood center, said that the organization “never had any obligation for care for the chimps, contractual or otherwise.”
Primatologists and animal welfare advocates reacted with outrage.
“I have studied great apes for 20 years in all contexts across the globe — labs, zoos, sanctuaries, the wild,” Brian Hare, an anthropologist and primatologist at Duke University, wrote in an email at the time. “Never, ever have I seen anything even remotely as disgusting as this.”
Protests were held at the blood center’s headquarters in New York. The Humane Society began supporting the chimps and pressuring the blood center to take on some of the financial burden.
The Humane Society and the blood center have been negotiating off and on for the last few years. The Humane Society gained the help of Bill Richardson, a former governor of New Mexico, and other prominent people in talking to the blood center, which Mr. Pacelle said had been “incredibly resistant.”
He described the agreement as “a real turnaround for the blood center” and said “the sensible voices within their organization prevailed.”
“We’re very pleased,” Mr. Pacelle added.
Robert Purvis, a spokesman for the blood center, said reaching an agreement was a complicated process. “The blood center has been looking for an organization to take on the care of the chimpanzees for the last 10 years,” he said.
Fortunately, he said, “Nobody gave up.”