An official for the Centers for Disease Control and Prevention said late Wednesday that the agency cleared a second Dallas nurse diagnosed with Ebola for travel on Monday because she had no symptoms of the deadly disease.CDC spokesman David Daigle says Amber Joy Vinson, 29, spoke with a CDC official responsible for monitoring her health before she boarded the flight from Cleveland to Dallas on Monday.

Daigle said Vinson reported her temperature was below 100.4 degrees and that she had no symptoms. Ebola sufferers aren’t contagious until they show symptoms.

The official said she could board Frontier Airlines Flight 1143. She was among 132 passengers aboard.

Vinson, the second nurse to contract Ebola in the United States, was flown to Atlanta for treatment on Wednesday. She was diagnosed with Ebola late Tuesday and had been monitoring her health and reporting her temperature to CDC epidemiology teams routinely, according to Dallas NBC affiliate NBCDFW-TV5.

In fact, she called the CDC several times before boarding the plane concerned about her fever, according to a report from CBS News Medical Correspondent Dr. John LaPook.

“This nurse, Nurse Vinson, did in fact call the CDC several times before taking that flight and said she has a temperature, a fever of 99.5 ”” and the person at the CDC looked at a chart and because her temperature wasn’t 100.4 or higher, she didn’t officially fall into the category of high risk,” he said.

Vinson was among as many as 70 medical practitioners treating Thomas Eric Duncan at Texas Health Presbyterian Hospital in Dallas.

Duncan, the first U.S. Ebola patient, died on Oct. 8 from the virus.

The first nurse to contract the disease, Nina Pham, 26, became ill treating Duncan. She tested positive for the disease on Sunday and was listed in good condition Wednesday in Dallas after receiving blood from an Ebola survivor.

Duncan, who was in his early 40s, flew into Dallas-Fort Worth International Airport on a United Airlines flight from Washington’s Dulles Airport. The case led U.S. officials to expand health screening of passengers from West Africa who arrive at five major U.S. airports.

CDC Director Dr. Thomas Frieden disclosed Vinson’s case on Wednesday. He said that her self-monitoring found her temperature to be 99.5 ”” short of the 100.4 fever threshold that would have required her to seek medical care given her recent exposure to an Ebola patient ”” and that she had not known Pham’s diagnosis when she boarded the plane on Monday.

“Although she did not report any symptoms and she did not meet the fever threshold of 100.4, she did report at that time she took her temperature and found it to be 99.5,” Frieden said.

He added that Vinson’s temperature and that she had been exposed to the virus via Duncan should have prevented her from getting on the plane.

“I don’t think that changes the level of risk of people around her,” Frieden said. “She did not vomit, she was not bleeding, so the level of risk of people around her would be extremely low.”

Vinson, who lived in Akron, Ohio, before moving to Dallas in 2012, flew from Dallas-Fort Worth to Cleveland on Friday, returning on Monday. The crew on the Frontier Airlines flight reported that Vinson showed no symptoms while on the plane.

She discovered she had a fever on Tuesday and was immediately isolated in a Dallas hospital.

Vinson’s preliminary diagnosis came back later that night and was announced on Wednesday.