Federal health officials on Wednesday defended their response to the monkeypox outbreak as they faced a grilling from lawmakers on Capitol Hill.

Members of the Senate Health, Education, Labor and Pensions Committee expressed their frustration with the Biden administration’s handling of the outbreak during a hearing in which they questioned Centers for Disease Control and Prevention Director Dr. Rochelle Walensky, National Institute of Allergy and Infectious Diseases Director Dr. Anthony Fauci, Food and Drug and Administration Commissioner Dr. Robert Califf and Health and Human Services Assistant Secretary Dawn O’Connell.

There have been more than 22,000 monkeypox cases in the U.S. and one death during the outbreak, according to CDC data. The number of cases, however, has been falling in recent weeks.

More than 59,000 infections have been reported globally.

“Too many missteps happened early on, and a couple hundred cases turned into 22,000,” said Sen. Patty Murray, D-Wash., the committee’s chairwoman.

Murray said she’s spoken to constituents who reported having difficulty getting tested, health care providers who had to go to great lengths to acquire therapeutics and public health officials who said communication from the federal government came too slow and was ambiguous. She also criticized the Biden administration over limited access to the vaccine.

“We have got to do better, not just on COVID, not just on monkeypox, but on public health threats, period,” she said. “Because we know there will be more.”

The top Republican on the panel, Sen. Richard Burr of North Carolina, said “by every measure, the response from the Biden administration on monkeypox crisis has been a catastrophic failure.”

“You repeated each of the mistakes of the early days of the COVID response, and the cultural arrogance from public health officials, who are supposed to be at the forefront of our response, let this country down again.”

He blasted the administration on testing and vaccines and also criticized federal regulators for make decisions “seemingly on the fly.” He pointed to the FDA’s emergency use authorization last month, amid a vaccine shortage, that allows for the Jynneos vaccine to be administered intradermally — into the topmost layer of skin — rather than subcutaneously — into the fatty tissue below. The strategy allows for one-fifth the amount of vaccine to be used per shot while providing the same immune response, health officials say.

“There were no public meetings of FDA, CDC outside experts to discuss relevant questions on the minds of impacted Americans to inform these decisions,” Burr said. “Health professionals were confused about the initial decision, and patients were scared that they were being experimented on.”

But the federal officials insisted they have always been hard at work to stay ahead of the virus.

Walensky said the CDC had been studying monkeypox for decades, which led to the development of experimental therapeutics and vaccines being used today. The agency engaged in outreach calls with tens of thousands of clinicians to educate them about a rare disease that few providers had experience with, she said. The CDC also launched public information campaigns aimed at mitigating infections, drastically ramped up testing capacity and began conducting vaccination drives at large LGBTQ events, Walensky said. The virus, which is transmitted through close or intimate contact, has primarily spread among gay and bisexual men.

Califf said the FDA quickly moved to accelerate vaccine production, authorized the new method for administering shots to stretch out supply and approved the smallpox treatment TPOXX for monkeypox patients.

And O’Connell said HHS’ Administration for Strategic Preparedness and Response began deploying vaccine doses from the national stockpile and ordered more shots when there were just a handful of cases in the U.S.

But the officials also acknowledged there were some hiccups. Walensky and Califf said there was never a shortage of tests, but Califf said there was limited access to tests “because of inefficiencies in the system.” Walensky said some of the frustration about testing was a result of people without symptoms requesting tests, which require a rash to be swabbed. 

And O’Connell, who said in June that the government had the vaccine supply needed to manage the outbreak, explained that a change in vaccination strategy was needed when it became clear that “anonymized partners” made contact tracing difficult. Health officials expanded its recommendation for the shots to include those likely to be exposed rather than just close contacts of an infected person, leading to a vaccine shortage.

Lawmakers also pressed Califf on a delay of vaccine shipments from Denmark because the FDA needed to inspect the plant. He explained it was a new plant that had not been previously inspected by U.S. officials, and he pointed to problems with U.S. plants producing COVID-19 vaccines as evidence of why the agency’s diligence was necessary. 

“We really felt we had to get this right, even if it took a bit more time,” he said.

Wednesday’s hearing came as the Biden administration is asking Congress for $4.5 billion in emergency funding to tackle the monkeypox outbreak, as well as an additional $22.4 billion for its COVID-19 response.

Walensky said the monkeypox funding is needed “to support testing and laboratory capacity expansion, vaccination efforts, surveillance, epidemiologic investigations, outreach, education and global efforts.”