CNN  — 

President Donald Trump has lost patience with the head of the US Centers for Disease Control and Prevention, Dr. Robert Redfield, as well as with the other public health experts on his coronavirus team because their sober messaging on the future of the pandemic clashes with his rosy assessments.

Trump believes that breakthroughs are not coming swiftly enough, according to people familiar with the President’s thinking. Trump’s frustrations have caused some to question whether Redfield is on the chopping block, but a Trump adviser said they did not expect the President to make major staffing changes before the election.

The ever-looming threat, Trump’s public undermining of the CDC chief and Redfield’s tendency to fold to the White House are taking a toll on CDC staff, from top to bottom, employees say. Some have questioned whether their work is making a difference and others have even considered resigning – and whether the sagging spirits may be hampering pandemic response.

Eight current and former public health officials described for CNN a crushing environment at the agencies charged with the coronavirus response brought on by a President intent on contradicting critical public health messaging and downplaying the threat of the virus, politically motivated pressure from the White House and baseless allegations from political appointees that government scientists are part of a disloyal “deep state.”

“The morale is as low as I’ve ever seen it and we have no confidence in our leadership,” a CDC official said. “People are miserable and it’s a shame because this pandemic is still flying away and we still need a robust public health response.”

Inside the White House, Drs. Deborah Birx and Anthony Fauci have struggled to compete with the growing influence of Trump’s new favorite coronavirus adviser, Dr. Scott Atlas, a neuroradiologist with no public health or infectious disease expertise whose views are wildly out of step with leading public health experts. Birx has told people around her she is “distressed” with the direction of the task force and is uncertain how much longer she can continue to serve as the coronavirus task force coordinator.

And at the FDA, the agency’s top career officials penned a Washington Post op-ed earlier this month reasserting the agency’s independence and commitment to science amid political pressure from the White House and “deep state” allegations from the President.

In a nod to the dispirited mood engulfing his agency, Redfield registered his disappointment during a Senate hearing on Wednesday with since-departed top Department of Health and Human Services spokesman Michael Caputo’s wild accusations that CDC scientists are part of a “deep state” engaging in “sedition.”

“I want to add, you know, how disappointed I have been personally when people at HHS made comments that they felt there was a deep state down at CDC,” Redfield said, calling the comments “offensive.”

“Obviously people don’t understand the ability to suck energy out of people that are working 24/7 when they get unfairly criticized or unfairly characterized, and really that’s the real harm in all this,” Redfield said, without noting that Trump has also maligned some government scientists as being part of a “deep state.”

Health experts and career officials working on the pandemic response across the administration are feeling the same pressure and disillusionment as CDC officials.

“I think that this has been a growing frustration for months. And now it’s just getting worse,” said Olivia Troye, who resigned last month as Vice President Mike Pence’s homeland security adviser after months working with the coronavirus task force.

Troye said the endless work of public health experts combined with undercutting from the President and the White House has left many of the public health experts she worked with demoralized.

“It is incredibly difficult to spend your entire life’s work for a greater mission on behalf of the American people and have the White House and the people at the top completely disregard it,” Troye said. “And it’s not just one time, it’s nonstop.”

Redfield’s comments during his congressional testimony on Wednesday only scratched the surface of the deep unease within his own agency that has been fueled in part by how he has steered the agency, bent to pressure from Trump and the unforced errors that have happened under his watch.

Recently, the blows to the CDC have come at rapid-fire pace.

Last month – under direction from the White House’s testing czar – the CDC altered coronavirus testing guidelines to dissuade some asymptomatic individuals from getting tested despite growing evidence about asymptomatic individuals spreading the virus. The decision was roundly criticized by public health experts both inside and outside of the administration.

Amid the uproar, the CDC last week reversed course.

Redfield has also lost the confidence of some of his agency’s staff in part because he has caved repeatedly to White House pressure and public admonitions by the President himself.

Later on Wednesday, Redfield was once again contradicted from the White House podium – this time by Atlas. A federal health official said Redfield did not “outwardly” express “any frustration.”

Just last week, Redfield walked back strong and scientifically-based comments he made about the importance of masks and the timeline for a vaccine after Trump publicly contradicted him and said he had made a mistake. Some CDC sources said Redfield has been careful to toe the White House’s political line while two senior officials called Redfield an “ineffective communicator.”

Back on Capitol Hill this week, Redfield was facing questions over a fresh controversy: the removal of new guidance about airborne transmission of the virus that the agency said had been erroneously posted without being properly reviewed.

“I do think staff are feeling pretty down,” a veteran CDC official told CNN. “We pride ourselves on serving the American people and being accused of sedition or not being trusted weighs on us.”

While morale at the agency has taken a hit, the veteran official said, they hadn’t heard anyone voice any less commitment to doing the right thing and continuing to try and save lives.

But the unforced errors, undermining by the White House and what some referred to as Redfield’s “ineffective” leadership are taking a practical toll, making some CDC officials reluctant to rotate into the agency’s incident management structure for the coronavirus response – previously a coveted rotation – because of concerns about how the response is being handled and a sense of futility among some, one official said.

“Why spend a lot of time trying to do something that the government isn’t going to listen to or pay attention to,” this official said.

One 14-year veteran public health professional told CNN that she felt anxious to go into work everyday and it has driven her to get help for her mental health. The staffer, who was visibly upset during her interview with CNN, said that she sometimes felt embarrassed to work at the CDC and has thought often about quitting.

“There is no compassion, no understanding. It’s a ‘Don’t Complain’ culture,” the public health official said.

CNN’s Jim Acosta contributed to this report.