Scientists are a step closer to finding the first effective treatments for the deadly Ebola haemorrhagic fever after two potential drugs showed survival rate of as much as 90% in a clinical trial in Congo.

Two experimental drugs - Regeneron's REGN-EB3 and a monoclonal antibody called mAb114 - were both developed using antibodies harvested from survivors of Ebola infection.

The treatments are now going to be offered to all patients in the Democratic Republic of Congo (DRC), according to U.S. National Institute of Allergy and Infectious Diseases.

They showed "clearly better" results in patients in a trial of four potential treatments being conducted during the world's second largest Ebola outbreak in history, now entering its second year in DRC.

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In 2000, Gavi, the Vaccine Alliance was launched at the World Economic Forum's Annual Meeting in Davos, with an initial pledge of $750 million from the Bill and Melinda Gates Foundation.

The aim of Gavi is to make vaccines more accessible and affordable for all - wherever people live in the world.

Along with saving an estimated 10 million lives worldwide in less than 20 years,through the vaccination of nearly 700 million children, - Gavi has most recently ensured a life-saving vaccine for Ebola.

At Davos 2016, we announced Gavi's partnership with Merck to make the life-saving Ebola vaccine a reality.

The Ebola vaccine is the result of years of energy and commitment from Merck; the generosity of Canada’s federal government; leadership by WHO; strong support to test the vaccine from both NGOs such as MSF and the countries affected by the West Africa outbreak; and the rapid response and dedication of the DRC Minister of Health. Without these efforts, it is unlikely this vaccine would be available for several years, if at all.

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The drugs improved survival rates from the disease more than two other treatments being tested - ZMapp, made by Mapp Biopharmaceutical, and Remdesivir, made by Gilead Sciences - and those products will be now dropped, said Anthony Fauci, one of the researchers co-leading the trial.

The agency said 49% of the patients on ZMapp and 53% on remdesivir died in the study. In comparison, 29% of the patients on REGN-EB3 and 34% on mAb-114 died.

Fauci, director of the U.S. National Institute of Allergy and Infectious Diseases, told reporters in a telebriefing the results were "very good news" for the fight against Ebola.

"What this means is that we do now have what look like (two) treatments for a disease for which not long ago we really had no approach at all," he said.

The agency said of the patients who were brought into treatment centres with low levels of virus detected in their blood, 94% who got REGN-EB3 and 89% on mAb114 survived.

In comparison, two-third of the patients who got remdesivir and nearly three-fourth on ZMapp survived.

Ebola has been spreading in eastern Congo since August 2018 in an outbreak that has now become the second largest, killing at least 1,800 people. Efforts to control it have been hampered by militia violence and some local resistance to outside help.

A vast Ebola outbreak in West Africa become the world's largest ever when it spread through Guinea, Liberia and Sierra Leone from 2013 to 2016 and killed more than 11,300 people.

Image: WHO

The Congo treatment trial, which began in November last year, is being carried out by an international research group coordinated by the World Health Organization (WHO).

Mike Ryan, head of the WHO's emergencies program, said the trial's positive findings were encouraging but would not be enough on their own to bring the epidemic to an end.

"The news today is fantastic. It gives us a new tool in our toolbox against Ebola, but it will not in itself stop Ebola," he told reporters.

Jeremy Farrar, director of the Wellcome Trust global health charity, also hailed the success of the trial's findings, saying they would "undoubtedly save lives".

"The more we learn about these two treatments, ...the closer we can get to turning Ebola from a terrifying disease to one that is preventable and treatable," he said in a statement.

"We won't ever get rid of Ebola but we should be able to stop these outbreaks from turning into major national and regional epidemics."

Some 681 patients at four separate treatment centres in Congo have already been enrolled in the Congo treatment clinical trial, Fauci said. The study aims to enrol a total of 725.