AMNA NAWAZ: Former USAID employees who have been fired or placed on leave by the Trump administration began making their final visits to the agency's headquarters today to pack up their belongings.

Carrying bags of personal items, workers were surrounded by supporters cheering them on.

They include Samantha Power, who served as the agency's administrator under President Biden.

SAMANTHA POWER, Former USAID Administrator: The people who are walking out of this building are American heroes.

They did not come to USAID for the money.

They didn't come for the glory.

We rightly honor our men and women in uniform.

These are heroes who don't wear uniforms.

And they are being treated in a manner that nobody should treat their worst enemy, and they're being treated that way by their own government.

AMNA NAWAZ: With nearly all of the agency's work abroad now suspended, our Laura Barron-Lopez takes a closer look at one USAID effort that's been caught in the political crossfire.

LAURA BARRON-LOPEZ: In a meeting with President Trump's Cabinet this week, Elon Musk, the architect of the Trump administration's jobs cuts and contract cancellations, defended the actions his team has made over the last month.

ELON MUSK, Department of Government Efficiency: We will make mistakes.

We won't be perfect.

But when we make mistake, we will fix it very quickly.

So, for example, with USAID, one of the things we accidentally canceled very briefly was Ebola, Ebola prevention.

I think we all want Ebola prevention.

So we restored the Ebola prevention immediately.

And there was no interruption.

LAURA BARRON-LOPEZ: But public health experts and current and fired USAID workers say Musk is wrong.

USAID's Ebola prevention efforts have been frozen since the agency was largely dismantled.

For more, I'm joined by Dr. Craig Spencer.

He's professor at Brown University School of Public Health and survived Ebola after treating patients in Guinea with Doctors Without Borders in 2014.

Dr. Spencer, you heard Elon Musk's claim that Ebola prevention is fixed and that there were no disruptions caused.

But the USAID workers I talked to say that's not true.

Where does Ebola prevention currently stand?

DR. CRAIG SPENCER, Brown University School of Public Health: Well, let's be clear.

What Elon is claiming, that Ebola prevention was turned off, but has been turned back on again, is just flatly untrue.

This is a theme that we have seen emerge, whether it's firing hundreds of nuclear weapons safety experts or bird flu experts at the USDA scrambling to try to hire them back and saying that we fixed the problem.

The reality is that there is no budget line for -- quote -- "Ebola prevention" either at the USAID or anywhere across the government.

The work that goes into preventing Ebola is the same work that goes into preventing other infectious diseases from breaking out in places around the country and around the world.

That involves funding for USAID, sure.

It also involves support for the CDC, where 750 employees have been laid off, some of our best disease detection experts in the world.

It also involves supporting and working together with the World Health Organization, something that our government has made impossible and strictly said that you're not allowed to do within the past few weeks.

All of these things together are what Ebola prevention is in this country.

None of them have been turned back on.

In fact, as of today, I can guarantee, after speaking with the people that would be doing these things, they remain turned off.

LAURA BARRON-LOPEZ: The Ebola outbreak in Uganda appears to be receding, however.

But in the immediate weeks after the January 29 outbreak, you said that there was a lot of confusion in Uganda about how to get help from the U.S. Can you just give us a quick sense of what that was like?

DR. CRAIG SPENCER: Well, normally, we would have these communication chains, where the Uganda Ministry of Health would call the CDC, would get in touch with the White House, where they would mobilize people in treatment, support logistics.

USAID would help set up security screening and border screening at the airport in Entebbe in Uganda.

None of those things happened.

I know none of them happened, because I talk to the people that would have been on a plane normally to respond.

I talked to the people that just weeks prior had been in charge of the NSC of global health in the White House who said that there wasn't someone in that role for days, up to a week.

LAURA BARRON-LOPEZ: The administration seems to be claiming that they have created waivers or some of this aid is turned back on.

Secretary of State Marco Rubio said that he signed waivers for key aid, including PEPFAR, which is the program that delivers medication to come down, which is the program that delivers medication to combat AIDS.

But the sources that I talked to and others have reported that that aid is not necessarily reaching the people it needs to reach.

How serious is that?

DR. CRAIG SPENCER: It's incredibly serious.

And you're right.

I have spoken to a lot of people that lead USAID programs all over the world, and they have guaranteed to me and confirmed that those waivers, if they're coming at all, are not really helping.

You don't have USAID people to pay those out.

We have the funding that has been freed.

So, you're right, those waivers have not been much of assistance.

The result is that we had over 20 million people around the world, including 500,000 children, who were receiving HIV treatment as part of PEPFAR, the most impactful and successful global health program ever, started under George W. Bush.

Right now, 20 million people risk losing access to those medications.

The result is going to be more infections of HIV, more people whose infections were controlled that will be uncontrolled, greater risk of global spread.

And PEPFAR has also been essential for setting up disease detection systems all around the world.

LAURA BARRON-LOPEZ: Elon Musk claims that foreign aid is -- quote -- "waste," it's -- quote -- "fraud."

And in a court filing this week, the administration said that they terminated 92 percent of U.S. foreign aid contracts.

The White House argues that this money shouldn't be spent abroad, that it should be spent at home for Americans.

So why should Americans be concerned about the dramatic cuts to international health?

DR. CRAIG SPENCER: Absolutely no one listening to this program has had smallpox.

Maybe some people have been vaccinated against it.

But the United States, along with the USSR, at the height of the Cold War, put together a plan to eradicate smallpox, one of the worst diseases in human history.

And, in 1980, they did.

They spent $300 million together to eradicate smallpox from the face of the earth.

And, because of that, we saved billions and billions and billions of dollars by stopping the disease from spreading internationally, from having to vaccinate or treat for smallpox here in the United States.

It was an unbelievably efficient and incredible return on investment.

The diseases that we're seeing in other places around the world can have a similar economic toll, in addition to a similar human toll.

It is in our best interest to detect and fight outbreaks where they occur, as opposed to waiting for them to come to where we are.

As of right now, if the U.S. is not going to show up and support health systems and this disease outbreak worker around the world, countries will have no incentive to be transparent.

They will have no reason to share with us that there is a disease outbreak.

They will get bigger faster.

They will create more of a risk on the ground, and there will be a greater chance that they impact us and infect us here in the United States.

I promise you, we will regret this.

LAURA BARRON-LOPEZ: Dr. Craig Spencer, thank you for your time.

DR. CRAIG SPENCER: Thank you.