President Barack Obama said Tuesday that Americans deployed to West Africa since August have had a positive impact in the fight against the Ebola virus. “They are starting to see some progress in Liberia,” he said. “That’s thanks to the incredible work and dedication of folks from the United States who are leading the way in helping Liberia, Guinea and Sierra Leone,” Obama added, referring to the three countries hit hardest by the disease.

The president also said it’s important to have “sensible” monitoring of health care workers who return from fighting Ebola in West Africa to the United States, as well as to make sure those workers are supported and applauded. “We don’t want to discourage our health workers from going to the front lines and dealing with this in an effective way,” Obama said.

The president’s address comes on the same day Northeast Ohio native Amber Vinson was released from the hospital after health officials say the Ebola virus is no longer in her system. President Obama said he spoke to Vinson on the phone today.

*CLICK to watch Vinson’s statement*

Ebola has killed more than 4,900 people, mostly in the West African nations of Liberia, Sierra Leone and Guinea, and infected thousands more in what health officials call the worst outbreak of the disease in history. The World Health Organization has said that the mortality rate in the current outbreak, starting with the first death in December, is about 70%.

Vinson’s release leaves only one confirmed Ebola patient — Dr. Craig Spencer, 33 — in a U.S. hospital. Spencer, who was diagnosed with Ebola last week in New York after being in contact with Ebola patients in Guinea, was in serious but stable condition in a New York hospital Tuesday, according to New York health officials.

U.S. facilities have treated nine Ebola patients in recent months, and only one — Duncan — has died. All but Vinson and Pham contracted the disease in West Africa.

Many of the nine patients were given experimental treatments and transfusions of plasma from Ebola survivors, though doctors have cautioned that they’re not sure whether the measures helped.

Meanwhile, a patient who was tested for Ebola was negative for the virus, a spokeswoman for the University of Maryland Medical Center in Baltimore said Tuesday morning. The center had said a day earlier that it was treating a potential Ebola patient.

Child doesn’t have Ebola, but still hospitalized

A 5-year-old boy who recently visited West Africa and had a fever tested negative for the virus in New York, health officials said. A respiratory infection caused the child’s temperature to spike, which initially caused concern that he might have had the Ebola virus, New York City’s Bellevue Hospital Center reported Tuesday.

The boy is being taken out of isolation, CNN has learned, but he’ll remain hospitalized.

**Read more on the Ebola scare here**