The head of the Food and Drug Administration faced bipartisan fury from House lawmakers Wednesday over months of delays investigating problems at the nation’s largest baby formula plant that prompted an ongoing shortage.

FDA Commissioner Robert Califf laid out a series of setbacks in congressional testimony that slowed his agency’s response, including a COVID-19 outbreak at the plant and a whistleblower complaint that didn’t reach FDA leadership because it was apparently lost in the mail.

Califf testified before a House subcommittee probing the shortage, which has snowballed into a major political controversy and forced the U.S. to begin airlifting products from Europe.

The FDA’s response was: “Too slow and there were decisions that were suboptimal along the way,” Califf told lawmakers.

The FDA and President Joe Biden face mounting pollical pressure to explain why they didn’t intervene earlier to try and head off the supply crisis.

“Why did it take an onslaught of national media attention for the Biden administration to act with a sense of urgency required to address an infant formula shortage?” asked Rep. Morgan Griffith, R-Virginia, the committee’s ranking Republican. The panel is also scheduled to hear from three formula manufacturers, including Abbott Nutrition.

The shortage mostly stems from Abbott’s Michigan plant, which the FDA shut down in February due to contamination issues. Califf gave the first detailed account of why his agency took months to inspect and shutter the plant despite learning of potential problems as early as September.

“We knew that ceasing plant operations would create supply problems but we had no choice given the insanitary conditions,” Califf said in opening testimony.

FDA staff began honing in on Abbott’s plant last fall while tracking several bacterial infections in infants who had consumed formula from the facility. The four cases occurred between September and January, leading to hospitalization and two deaths.

The FDA planned to begin inspecting the Sturgis, Michigan, plant on Dec. 30, according to Califf’s testimony. But Abbott warned that about a dozen of its employees had tested positive for COVID-19 and requested a delay. As a result, the FDA didn’t begin its inspection until Jan. 31.

After detecting positive samples of a rare-but-dangerous bacteria in multiple parts of the plant, the FDA closed the facility and Abbott announced a massive recall of its formula on Feb. 17.

Abbott and the FDA have reached an agreement to reopen the plant next week, under which the company must regularly undergo outside safety audits.

Califf also struggled to explain the FDA’s months-long timeline in responding to an October whistleblower complaint alleging numerous safety violations at Abbott’s plant, including employees falsifying records.

Several FDA staffers reviewed the complaint in late October when it was sent to a regional FDA office, but an interview didn’t take place until two months later, in part due to the whistleblower’s scheduling conflicts.

Senior FDA officials eventually received the complaint via email, but not until February due to “an isolated failure in FDA’s mailroom, likely due to COVID-19 staffing issues,” according to the FDA testimony. A mailed copy addressed to then-acting commissioner Dr. Janet Woodcock has still not been located.

Political outrage over the shortage has landed squarely on the FDA and Califf, the only administration official who has testified thus far on the issue. The problems have escalated into a political firestorm for the White House, which has invoked the Defense Production Act and emergency flights to shore up supplies.

Califf also faced questions about why his agency didn’t anticipate the shortage, given that Abbott’s plant supplies roughly one-sixth of the U.S. formula supply. FDA did not contact the U.S. Department of Agriculture about a potential shortage until Feb. 11., just days before Abbott’s recall, according to Califf.

Califf said the FDA has requested new authorities, funding and staff to track supply chain data that could have helped get ahead of the problem, but has not received them from Congress.

“Until regulatory agencies have digital access to critical supply chain information and personnel to do the work, we’ll continue to react to disruptions rather than prevent them,” Califf said.

Behind the shortage are other distinct factors, including industry consolidation that’s made the U.S. formula market vulnerable to disruptions at individual companies.

An Abbott executive is expected to tell the committee that his company will invest in additional capacity and supply chain safeguards. After the company restarts production next month it will be able to produce more formula than before the recall, according to prepared remarks from Abbott’s senior vice president, Christopher Calamari.

The company will restate its contention that there is no direct link between its formula and the infant infections investigated by the FDA. Agency regulators have said the small number of cases and incomplete testing data make it hard to draw a direct connection between the illnesses and Abbott’s plant.

Executives from Reckitt and Gerber are also scheduled to testify.

(AP)