Dr. Stephen Hahn’s first day as F.D.A. commissioner came just six weeks before Mr. Azar declared a public health emergency on Jan. 31. A radiation oncologist and researcher who helped turn around MD Anderson in Houston, one of the nation’s leading cancer centers, Dr. Hahn had come to Washington to oversee a sprawling federal agency that regulates everything from lifesaving therapies to dog food.
But overnight, his mission — to manage 15,000 employees in a culture defined by precision and caution — was upended. A pathogen that Mr. Trump would later call the “invisible enemy” was hurtling toward the United States. It would fall to the newly arrived Dr. Hahn to help build a huge national capacity for testing by academic and private labs.
Instead, under his leadership, the F.D.A. became a significant roadblock, according to current and former officials as well as researchers and doctors at laboratories around the country.
Private-sector tests were supposed to be the next tier after the C.D.C. fulfilled its obligation to jump-start screening at public labs. In other countries hit hard by the coronavirus, governments acted quickly to speed tests to their populations. In South Korea, for example, regulators in early February summoned executives from 20 medical manufacturers, easing rules as they demanded tests.
But Dr. Hahn took a cautious approach. He was not proactive in reaching out to manufacturers, and instead deferred to his scientists, following the F.D.A.’s often cumbersome methods for approving medical screening.
Even the nation’s public health labs were looking for the F.D.A.’s help. “We are now many weeks into the response with still no diagnostic or surveillance test available outside of C.D.C. for the vast majority of our member laboratories,” Scott Becker, chief executive of the Association of Public Health Laboratories, wrote to Mr. Hahn in late February. “We believe a more expeditious route is needed at this time.”
Ironically, it was Mr. Azar’s emergency declaration that established the rules Dr. Hahn insisted on following. Designed to make it easier for drugmakers to pursue vaccines and other therapies during a crisis, such a declaration lets the F.D.A. speed approvals that could otherwise take a year or more.
But the emergency announcement created a new barrier for hospitals and laboratories that wanted to create their own tests to diagnose the coronavirus. Usually, they faced minimal federal regulation. But once Mr. Azar took action, they were subject to an F.D.A. process called an “emergency use authorization.”
Even though researchers around the country quickly began creating tests that could diagnose Covid-19, many said they were hindered by the F.D.A.’s approval process. The new tests sat unused at labs around the country.