A new Ebola vaccine is safe to use and highly effective against the deadly virus, scientists say, following successful trials in Guinea and Sierra Leone. The scientists' study, published in the Lancet, notes that zero cases of Ebola were reported in Guinean subjects vaccinated with rVSV-ZEBOV immediately after contact with another Ebola patient, suggesting a 100 percent success rate against the disease.

The vaccine was hurried into development after last year's outbreak of the disease in west Africa in which more than 10,000 people are believed to have died. Scientists had previously struggled to combat the Ebola virus, but the new vaccine was found to be so effective that control group tests were halted early in Guinea, allowing everyone exposed to the disease to be immunized.

The trials were so successful they were stopped early

Scientists had previously split the test subjects up, giving some the vaccination immediately after Ebola contact, and waiting three weeks before providing it for others. 5,837 people received the vaccine during the Guinea trial in total, with 23 cases of Ebola reported in those who got the delayed vaccine, and zero among those who got it immediately.

"We have to get ahead of the curve and make promising diagnostics, drugs and vaccines for diseases we know could be a threat in the future," Jeremy Farrar of the Wellcome Trust told the Guardian. “Had a vaccine been available earlier in the Ebola epidemic, thousands of lives might have been saved."

The manufacturer of the vaccine has applied for it to be fast tracked

It's not clear when the vaccine will go into full production, but Merck and Co. — the pharmaceutical firm that will manufacture the vaccine — has already received permission to to fast-track its licensing procedures in the US and Europe. The trials themselves were funded by organizations like the WHO, as well as the Canadian and Norwegian governments.

The World Health Organization had come under fire for its slow response to the Ebola epidemic in west Africa, but the discovery of a vaccine that had previously eluded scientists should help save thousands of lives in the future. Farrar says this global approach can help quash epidemics faster. "My hope is that this success story provides the inspiration we need to make this happen and change the way the world prepares for epidemics," he said.