Federal officials are working to fast-track the development of an Ebola vaccine and hope to begin human trials in September, said a top National Institutes of Health official Thursday, as the outbreak of the deadly disease worsened in West Africa.

“We’re trying to go as quickly as we can given the emerging nature of the situation,” said Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases.

Fauci said that NIH researchers working on a vaccine have seen “pretty encouraging” results on tests in primates. Now, he said, he is working with the Food and Drug Administration to get approval to begin early-stage human testing.

That “Phase I” trial would involve about 20 people and could be wrapped up as soon as January, he said. If the vaccine proves safe and shows signs of effectiveness, researchers could conduct more robust human trials later in 2015.

Getting to that point could be valuable, Fauci added, because even if the drug isn’t approved, “by then, if you needed it on an emergency basis, you could vaccinate health workers.”

Part of the problem in moving forward with a vaccine has been a lack of interest from drug companies, given the small potential market. The latest outbreak in West Africa appears to have altered the views of at least some companies.

“It went from very little interest to, ‘If you can show us by January that it’s safe . . . we’ll be more than happy to partner with you,’ ” Fauci said.