U.S. FDA commissioner Stephen Hahn appeared before a congressional panel to discuss the administration’s budget proposal for the agency, but the outbreak of COVID-19 predictably dominated the proceedings. Hahn was grilled about the fact that South Korea had deployed many more tests for the underlying pathogen, but he noted that U.S. tests have to operate on a wide range of testing platforms, which has complicated the task of test development in the U.S.
The hearing before the House Appropriations subcommittee for the FDA and related agencies was not yet over when the World Health Organization declared the COVID-19 outbreak an epidemic. Hahn said, however, “that doesn’t change what we need to do in this country,” noting that the U.S. federal coronavirus task force has posted a series appropriate precautions to be used for home, work and school safety.
Hahn said the FDA saw test sensitivity as critical to ensure that any negative results are true negatives, a position the agency took based on the available science. This along with the need to develop a test that runs across the entirety of the installed base of testing platforms in the U.S. incurred some drag on the U.S. federal government effort to deploy a test.
Hahn’s remarks regarding multiple testing platforms was in response to a question about testing capacity in the state of New York, although he was also questioned about drive-through testing in South Korea. He noted that the FDA did somewhat loosen the regulations in developing its emergency use authorization policy, particularly for CLIA-certified academic labs. These labs can deploy a validated test and have 15 days to inform the FDA of the use of that test, but in the meantime, “you can begin testing patients,” he said.
CDC eyes single-test policy
At present, Hahn said, “all public health labs in this country have tests,” but he emphasized that this is in reference to individual tests rather than test kits. He said approximately 200,000 tests have been sent to public health labs in recent days, and that roughly 2.5 million total tests have been made available in the U.S. Given that most patients will need more than one test, Hahn said that this should translate to a testing capacity for more than 980,000 patients. However, he noted that the CDC has posted an updated policy stating that anyone testing positive for an alternative respiratory pathogen need not be tested a second time for the SARS-CoV-2 virus, but which also allows a lab to combine samples from a given patient into a single test.
Hahn said he could not confirm a claim that the existing lab capacity could process only 16,000 tests per day, but acknowledged that there is some pressure on reagent production. The FDA is working with labs for alternatives for reagents, he said.
More than one member of the committee asked Hahn about production of drug substances, including active pharmaceutical ingredients (APIs) in overseas labs, and he noted that one of the agency’s answers for this predicament is to encourage the use of advanced drug manufacturing. However, he pushed back on the claim that only U.S. drug and device manufacturing sites are subject to surprise inspections, although he noted that most OUS sites are notified as much as 12 weeks in advance.
The FDA posted a February 2019 draft guidance for continuous pharmaceutical manufacturing, a move Hahn said might help drug makers relocate facilities to the U.S. He said the drug supply is safe and secure, but that policymakers need to look at manufacturing redundancy, including API production, which Hahn characterized as “an issue of utmost importance, and I think it’s been highlighted by the coronavirus outbreak.”
There is currently no evidence that the new coronavirus is transmitted through the blood supply, but Hahn said there are concerns about a drop in donations. “We encourage Americans to continue to donate blood,” consistent with local health department recommendations regarding gatherings in public places.
CDC’s Redfield says South Korean test unworkable in U.S.
Earlier in the day March 11, the House Committee on Oversight and Government Reform held a hearing on the federal government response to the COVID-19 outbreak, which brought to light a few details about the test developed by the CDC, details that seemed to do little to mollify the agency’s critics on Capitol Hill.
CDC director Robert Redfield said one of the differences between the test now used in the U.S. and the test used in South Korea is that the U.S. approach relies on thermocycling to ensure applicability across a range of platforms. Redfield described the test in use in South Korea as a high-throughput test, although he did not characterize the underlying technology. The CDC has said rapid influenza diagnostic tests can miss 50% to 70% of cases that can be picked up by more thorough means, such as real-time polymerase chain reaction testing.
Redfield said the South Korean test is a single immunoglobulin test that measures antigens, which is based on a molecular test. The CDC test is a serological test that is designed to map out the extent of an outbreak, and he said CDC is working on two additional serological tests. Redfield said the test used in South Korea would have to go through the FDA regulatory approval process prior to deployment, adding that none of the public health labs in the U.S. could have used the South Korean test because they don’t have the correct instrumentation.
There are no plans for drive-through testing in the U.S. because government officials are trying to maintain the relationship between patients and their health care professionals. Rep. Jim Cooper (D-Tenn.) alleged that this was motivated by an effort to allow physicians to profit from the crisis, but both Redfield and Fauci disputed that assertion, with Fauci explaining that not all patients with symptoms need to be tested. Contact with a health care professional ensures that tests are not used on patients who are not at a clear risk of having contracted the disease, he said.