The Pentagon is preparing for such tests next spring.
The market for such tests could be small if SARS does not remain a serious health threat.
For such tests, doctors remove immune cells and "activate" them with chemicals to make them reproduce.
It will take months to years for such tests to be completed, Dr. Keith Gottesdiener, a Merck vice president, said in an interview.
During a conference call with reporters Thursday, Robert B. Zoellick, the president of the World Bank, reiterated the need for such tests.
But it takes time for such tests to rise to abnormal levels, and further testing is needed to be sure he did not have a heart attack.
The European Commission has estimated that 9m animals may be used for such tests; some observers put the figure far higher.
A November 2011 agency report, which Iran vigorously disputed, said Parchin may have housed a large containment vessel for such tests between 2000 and 2003.
Charles L. Bailey, a former commander of the Army's laboratory at Fort Detrick, Md., said another problem was the shortage of research monkeys for such tests, although he said the government was now moving to address this issue.
A front-page article yesterday about clinical drug testing at academic institutions misstated the percentage of government funds for such tests that go to 40 of the nation's 125 medical schools.
Generally, Mr. Browne said, a candidate who passes the written test can be disqualified for failing a physical or psychological test, for not showing up for such tests, or if the department finds "character issues" in a background check.
