WASHINGTON (Reuters) - The U.S. National Institutes of Health said on Wednesday it is reducing the number of chimpanzees it uses in biomedical research and will retire most of them to sanctuaries, a decision applauded by animal rights groups.

“Chimpanzees are very special animals ... We believe they deserve special consideration,” said NIH Director Dr. Francis Collins, announcing the move.

The decision followed a recommendation by the U.S. Department of Health and Human Services in January. About 300 newly retired chimps will join more than 150 others in sanctuaries, with only 50 being kept for future research.

Animal rights groups applauded the move.

“This is an historic moment and major turning point for chimpanzees in laboratories — some who have been languishing in concrete housing for over 50 years,” said Wayne Pacelle, CEO of the Humane Society of the United States.

“PETA is popping champagne corks at their Norfolk, Virginia, headquarters today,” People for the Ethical Treatment of Animals said in a statement.

The NIH said those chimpanzees kept for research will not be bred and will be selected according to research projects that meet the funding criteria of the Institute of Medicine.

“Americans have benefited greatly from the chimpanzees’ service to biomedical research, but new scientific methods and technologies have rendered their use in research largely unnecessary,” Collins said in a video announcement.

“The likeness of chimpanzees to humans has made them uniquely valuable for certain types of research, but also demands greater justification for their use.”

Some of those justifications were suggested by the Institute of Medicine in 2011. It identified areas in which the use of chimpanzees was critical and could continue, including the development of vaccines for the hepatitis C virus.

“No other suitable animal models exist” to test vaccines for hepatitis C, it said in a report.

The number of chimps kept for research will be reviewed every five years to determine whether that is sufficient, said NIH spokesperson Renate Myles.

The NIH supports 360 of its own chimpanzees and 91 that are privately owned. It is unclear whether any privately owned chimpanzees will go toward the number being kept for research.

The Texas Biomedical Research Institute, an independent group, said it was disappointed in the decision to cut the research chimps to 50.

“This arbitrarily chosen number is not sufficient to enable the rapid development of better preventions and cures for hepatitis B and C, which kill a million people every year,” it said in a statement.

The sanctuary system, started in 2002, is already close to its $30 million funding limit, Collins said, and more funding will be needed to support the newly retired chimps.

The NIH did not accept all recommendations from the Institute of Medicine, however, saying there was a “lack of scientific consensus” about “ethologically appropriate facilities” granting each chimp 1,000 square feet of space.

PETA and the NIH both acknowledged a proposed rule from the U.S. Fish and Wildlife Service that would categorize captive chimpanzees as endangered, which would keep them from being used in invasive experiments altogether.

The NIH initially put limits on research using chimpanzees in December 2011 when it stopped funding new projects involving the animals.