Desrosiers said NEPRC—which allots animals to researchers from within and without the Center at the discretion of a special committee—has been relatively successful in meeting demand for monkeys so far.

“We have done okay and have been able to satisfy the needs of most of the scientists that we service. But it has been difficult obtaining rhesus monkeys on the open market,” he said in an e-mail.

But, he added, the Center may be relatively successful in meeting demand because many researchers, like Johnson, are already asking for fewer monkeys than they would request if there were no shortage.

“We have been able to meet over 80 percent of official requests,” he said. “But it is only fair to point out that these requests take into consideration the limited availability of rhesus monkeys.”

And researchers said they do not expect excessive demand for the rhesus monkeys to subside anytime soon—particularly under recent governmental pressure to pursue research combatting bioterrorism threats.

“It’s only going to get worse with the recent shift of resources to new biodefense initiatives,” Johnson said.

Continuing to meet the rising demand for monkeys will require a support system that does not exist at present, Desrosiers said.

“I think the need will continue to increase, and that appropriate plans and funding are not in place to increase the supply through increased breeding,” he said. “This requires an increase in facilities and infrastructure.”

The rhesus monkeys reproduce slowly, compounding the present shortage.

So far, NEPRC has been successful in securing the support it needs, he said. Anticipating a shortage, the Center has lobbied for more support and applied for a grants from the division of the National Institutes of Health responsible for funding primate research.

To date the NEPRC facility has received sufficient funding to breed more rhesus monkeys and to build new facilities, he said.

Still, for researchers working toward a cure for diseases like AIDS—even those who have been able to proceed with their projects—the monkey shortage has stands as a major obstacle, costing money and, more importantly, time.

“It’s become the major roadblock for vaccine trials,” Lieberman said.

—Staff writer Nathan J. Heller can be reached at heller@fas.harvard.edu.