It's a nightmare scenario worthy of a sci-fi movie script: A scientist accidentally pricks her finger with a needle used to inject the deadly Ebola virus into lab mice.

But in this case, it really happened — to an unidentified 45-year-old woman in Germany.

Within hours of the accident on March 12, several of the scientist's colleagues held a trans-Atlantic telephone conference to map out a way to save her life.

Within 24 hours, an experimental vaccine — never before tried on humans — was on its way to Germany from a lab in Canada.

Within 40 hours, the at-risk scientist was injected with the vaccine.

So far, so good. If the woman is still healthy on April 2, she can consider herself safe.

It's not a 100 percent certainty the researcher was actually infected with Ebola.

If she doesn't become infected, scientists may not know if it was the vaccine, or luck.