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LONDON - ENGLAND - SEPTEMBER 17: Dr Felicity Hartnell, who is a clinical research fellow at Oxford University, holds the vile of the ebola vaccine called Chimp Adenovirus type 3 (ChAd3) before the first healthy UK volunteer receives an ebola vaccine at the Oxford Vaccine Group Centre for Clinical Vaccinology and Tropical Medicine (CCVTM) on September 17, 2014 in Oxford, England. (Photo by Steve Parsons-WPA Pool/Getty Images)

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Health care workers, wearing protective suits, leave a high-risk area at the French NGO Medecins Sans Frontieres (Doctors without borders) Elwa hospital on August 30, 2014 in Monrovia. Liberia has been hardest-hit by the Ebola virus raging through west Africa, with 624 deaths and 1,082 cases since the start of the year. AFP PHOTO / DOMINIQUE FAGET (Photo credit should read DOMINIQUE FAGET/AFP/Getty Images)

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A health worker, wearing Personal Protective Equipment (PPE), and a woman pose on September 7, 2014 inside the high-risk area at Elwa hospital in Monrovia, which is run by the non-governmental international organization Medecins Sans Frontieres (Doctors without Borders -- MSF). US President Barack Obama said in an interview aired on September 7 the US military would help in the fight against fast-spreading Ebola in Africa, but warned it would be months before the epidemic slowed. The tropical virus, transmitted through contact with infected bodily fluids, has killed 2,100 people in four countries since the start of the year -- more than half of them in Liberia. AFP PHOTO / DOMINIQUE FAGET (Photo credit should read DOMINIQUE FAGET/AFP/Getty Images)

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Story highlights

A new study found an Ebola vaccine protected 100% of people who received it

The strategy used to deliver it was inspired by the strategy to eliminate smallpox

(CNN) —

An experimental vaccine against the Ebola virus was found to be 100% effective, according to a study published in The Lancet on Thursday.

The results offer hope of better protection against the disease that ravaged West Africa in 2014, killing more than 11,000 people.

“Ebola left a devastating legacy in our country. We are proud that we have been able to contribute to developing a vaccine that will prevent other nations from enduring what we endured,” said Dr. KeÏta Sakoba, the director of the national agency for health security in Guinea.

The vaccine

The experimental vaccine was given in 2015 to people in Guinea who were in contact with patients who had recently confirmed cases of Ebola.

A few months after the early trials, the World Health Organization said the preliminary results were an “extremely promising development.”

Initially, only people over the age of 18 were offered the vaccine and the participants receiving them were randomized.

But the process was stopped after initial results in order to get the vaccine to everyone in need of it.

The trial involved more than 11,000 people, according to the WHO who led the trial in conjunction with Guinea’s Ministry of Health.

When analyzing the results, the teams didn’t count people who got sick within the 10 days, as they were believed to have been infected before they received the vaccine. Waiting 10 days also gave volunteers time to build up an immunity after receiving the vaccine, according to Dr. Marie-Paule Kieny, the WHO assistant director-general and the study’s lead author.

Patients were either vaccinated immediately or after three weeks. As everyone had become eligible for the vaccine, the three-week group served as the control as they didn’t actually get the vaccine until it was clear that they were not infected (Ebola has an incubation time of two to 21 days), Kieny said.

Researchers followed up with immunized volunteers at their homes on days three, 14, 21, 42, 63 and 84 after receiving the vaccine.

02:14 - Source: CNN

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