Researchers at the University of Oxford say the Ebola vaccine they are currently testing on human volunteers has shown to be safe, with further tests about its effectiveness underway.

The vaccine’s development team led by Adrian Hill, professor and director of the Jenner Institute at University of Oxford, has tested three volunteers since Wednesday following animal trials.

“So far, everything is going very well. We had the first volunteer on Wednesday. We saw her on Thursday morning, she’s fine. And then we had two more yesterday morning, and they’re fine as well,” said the professor.

Hill said the vaccine his team is currently testing contains genetic material from the virus and that it is safe for human use.

The entire vaccine test, according to Hill, involves 60 volunteers, who will be divided into three groups and tested during separate time periods.

Each vaccinated volunteer will be asked to return to the lab nine times over the course of six months for data collection. Their body temperatures will also be monitored remotely by researchers.

Through the trials, researchers hope to identify whether the vaccine can effectively activate the immune system of a human body to generate enough antibiotics for combating the Ebola virus.

“The vaccine’s going to be safe, so I’m confident that’s going to be okay,” said Hill. “The really difficult estimate to make is how strong the immune responses are going to be. After all, we’re here giving just a single dose of vaccine, and many vaccines need two or three or even more doses. So that’s something that we will have to look at in the trials.”

The vaccine Hill’s team is testing has been tested successfully on monkeys, and has given subjects immunity to Ebola virus for 10 months.

Meanwhile, 10,000 doses of the vaccine are being produced for distribution upon confirmation of effectiveness in humans.

“By late November, we’d like to have enough safety data and enough immune response data telling us how the vaccine is working for WHO and other international authorities to take the difficult decision on whether this is a vaccine we should go ahead and deploy by the end of the year in West Africa,” Hill said.

He told the reporter that his most optimistic estimate is that the vaccine they are developing could be released at the end of this year.

His biggest concern, however, is that once the virus mutates, they may have to start all their test work all over again.