An experimental vaccine against the deadly Ebola virus made by researchers at Canada's national laboratory in Winnipeg was given to a German scientist who may have been infected during a lab accident last week.

The scientific director of the National Microbiology Laboratory said Canadian officials were asked to provide some vaccine to the unnamed woman within hours of the accident, which took place March 12. 

'It was a tremendous response on the Winnipeg side to get that out the same day and get it over and get this delivered.'— Dr. Heinz Feldmann

Dr. Frank Plummer said he and Dr. David Butler-Jones, Canada's chief public health officer, quickly came to the conclusion they would allow use of the unlicensed vaccine following a request from the woman's doctor. A team of international experts in viral hemorrhagic fevers had recommended use of the vaccine.

The vaccine was on its way to Germany the same day, Plummer said.

"It's a pretty unusual situation to be in. But we thought that there's a chance to save a life here," he said Thursday.

First person to receive vaccine

The vaccine arrived in Germany last Friday and was given to the woman the next day, making her the first person to receive this vaccine. The scientist who led the development team praised Canada's quick response.

"It was a tremendous response on the Winnipeg side to get that out the same day and get it over and get this delivered," said Dr. Heinz Feldmann, former head of the special pathogens unit at the Winnipeg lab.

"She got immunized within 40 hours after exposure. And considering that this had to be shipped across the Atlantic, I think that's quite an achievement."

Feldmann is now chief of the laboratory of virology at the U.S. National Institute of Allergy and Infectious Diseases' Rocky Mountain Laboratories in Hamilton, Mont.

He knows the woman but has not spoken with her since the accident. Feldmann said she made the decision to use the vaccine.

A news blog connected to the journal Science reported the woman's fever spiked about 12 hours after receiving the vaccine. While it's not clear if that was a response to the vaccine or a sign of onset of disease, the timing suggests it was a sign her system was responding to the vaccine, Feldmann said.

Lab worker pricked with needle

The woman, whose identity has not been revealed, pricked herself with a needle while working with Ebola virus at the Bernard Nocht Institute for Tropical Medicine in Hamburg. It's not yet known if she infected herself in the process.

Her temperature has since returned to normal. As of Thursday — a week after her accident — she was not showing any signs of disease. While that is considered a hopeful sign, the virus has an incubation period of between four and 21 days, so the woman is not yet in the clear.

"She's still within the window. But every day that goes by makes it more likely she'll be OK," Plummer said.

Feldmann suggested if she is still disease free by Monday, people may start to feel more comfortable.

The vaccine was made by scientists at the Winnipeg lab in collaboration with researchers from the U.S. Army Medical Research Institute for Infectious Diseases at Fort Detrick, Md., and the biodefence clinical research branch of the U.S. National Institutes of Health.

Testing on non-human primates has been positive

While testing in animals, including non-human primates, has been promising, the vaccine has never been tested on people. Plummer said the Winnipeg team calculated what they thought would be a human dose based on the work with macaque monkeys.

"You're really flying by the seat of your pants, because you don't know," he said.

A lab accident can be a nightmare in the research world. In 2004, a Russian scientist died following a similar exposure to the Ebola virus, which is one of the deadliest pathogens known to humankind.

Between 50 per cent and 90 per cent of people infected with Ebola virus succumb to a horrible death of internal bleeding. There is currently no cure, though some people have survived with what is called supportive care — essentially keeping patients hydrated while waiting for the body's immune response to catch up to and hopefully overtake the infection.

Word of the lab accident spread quickly within the small global community of researchers who work on Ebola and similar viruses. They convened a conference call to discuss options that might be open to the woman and recommended the Winnipeg vaccine.

Other vaccines in development

Several Ebola vaccines are in development and one, made by researchers at the U.S. National Institutes of Health, has even been safety tested in humans.

But the Winnipeg vaccine has been shown to increase chances of survival in what's called a post-exposure setting.

Most vaccines are given to prevent illness. But a few, like those for smallpox and rabies, are used after infection to help the immune system fight off the invading pathogen.

In a study published in 2007 in the journal PLoS Pathogens, the Winnipeg team reported three types of animals survived infection when given the vaccine post-infection. Four of eight primates injected with a lethal dose of Ebola virus survived when they were given the vaccine within 30 minutes of exposure.

The vaccine also protected 100 per cent of mice and 66 per cent of guinea pigs treated within the 30 minutes window. When researchers waited 24 hours to give infected guinea pigs the vaccine, 50 per cent survived.