In a rare appearance before a congressional panel, a top CDC official said Friday that there is no credible evidence that the agency is doing enough to protect the public against the virus.

“We’ve not been able to do that.

We’ve not done enough to prevent the spread of this virus,” said Dr. Kent Brantly, a senior epidemiologist at the CDC.

Brantly is one of three American aid workers who contracted Ebola while treating patients in Sierra Leone, and he was one of the first American to be diagnosed with the virus in the country.

He is also one of about a dozen Americans who have returned to the U.S. and who have been allowed to return home.

Brants return to the United States Thursday as part of a plea deal with federal prosecutors that calls for him to be sentenced to five years in prison, and then to be barred from re-entering the country for five years.

He is one more American to return to a U.s. city where the outbreak is still raging.

The three other American aid worker, Dr. Nina Pham and Dr. Ronny H. Cook, have been charged with infecting Americans with the disease.

Both are also accused of falsifying records to conceal their infection with the Ebola virus.

Pham and Cook were detained in Liberia, where they were caring for patients in a treatment center when they returned to their home country.

They have been imprisoned in Monrovia, Liberia.

In an interview Friday with NBC News, Brantly said he didn’t think the CDC had done enough in the face of Ebola to prevent people from contracting the disease, and said he thought the agency had been unfairly criticized for failing to get more Americans vaccinated.

“I don’t know what to say,” Brantly told NBC News.

“I think it’s unfair.

And I think it makes me angry.”

The CDC’s director, Tom Frieden, said the agency did not do enough to contain the spread, and has since tightened its policies to reduce exposure and keep infections at a low level.

Brant is the latest in a series of Americans to return from West Africa.

In January, a U-Haul truck carrying two American doctors from Texas, Drs.

Kent Bradley and Nancy Writebol, and a U.-Haul employee from Kentucky, Dr David Boren, arrived in New York City.

The pair were the first Americans to be infected with the coronavirus, and the first to be brought back from West African nations that are experiencing an epidemic.

Both patients had been released from quarantine in Liberia and Sierra Leone when they arrived.

In May, an American physician from Texas infected in West Africa was released from a hospital in Liberia.

Brances return to New York will be the first time the CDC has allowed Americans to come home since the virus became known in the United Nations.

Brantly and Pham will also be allowed to fly home, with Frieden saying he would like them to stay in New Jersey for the duration of their stay.

Brands have long been known to use anti-Ebola products to combat the virus, including one of Frieden’s favorite products, the Brantly-Baxley line of cough and cold cream.

The CDC has also been criticized for not having adequate measures in place to stop the spread.

The CDC, which is charged with running the nation’s response to the outbreak, said it had been in contact with the U-haul company and its staff to determine if there was any other anti-ebola product in use in Liberia before their return to their homes.