HAMILTON, Mont. -

The basis for an experimental Ebola vaccine is a virus found in cattle and horses. It's called vesicular stomatitis.

Scientists have genetically engineered an antigen, or foreign toxin, like Ebola, into that virus to spur an immune response.

The vaccine has been tested with great success on rodents and monkeys at Rocky Mountain Laboratories in Hamilton. The next step is human trials, which present new challenges.

Dr. Heinz Feldmann's life's work is attracting international press. The vaccine he helped develop first gained attention at a lab Feldmann was working at in Winnipeg, Canada, in 2005. It's a fast-acting emergency vaccine to be deployed during an ongoing Ebola outbreak. It isn't designed for patients who are already infected or ill.

Although Feldmann said it could be effective if a patient was vaccinated very early after infection, he said it's mostly for "protecting family members and health care workers through a rapid vaccination approach."

In 2009, a lab worker in Germany poked herself with an Ebola-infected needle. She agreed to take Feldmann's vaccine. She did, and she survived. Scientists don't know whether her own immune system kicked in, or whether the vaccine saved her. But it did not make her sick.

Feldmann feels confident the vaccine will not hurt anyone. He thinks it is time for human testing.

"Testing for adverse affects in humans in a small group of volunteers," he said, "and then looking for the immune response in humans."

Scientists around the world know getting investors for Ebola trials is a challenge. The disease is rare and has had limited outbreaks.

The doctor doesn't see the vaccine as an answer to Ebola. He sees it working in combination with other drugs and therapeutic treatment.

He said simple procedures like better hygiene, and using gloves and masks, are a huge help.

RML has video of Feldmann and other scientists visiting in the Republic of Congo. Teams trap bats, which are believed a source of the virus. They want to know how the disease is spreading.

"Studying potential transmission," said Feldmann, "how does the virus shed from the bat and how could humans and animals get infected."

Feldmann said a key to easing the crisis is to identify cases, isolate patients, and to contact every person who came in close contract with a patient.

He said that is becoming more difficult because resources in Africa are limited and the disease has spread to so many locations.