A mutation to allow the spread of Ebola through inhalation is one of the biggest fears
Researchers at the Institut Pasteur in France, the lab responsible for first identifying the outbreak back last March, have been tracking mutations in the fatal Ebola virus.
We know the virus is changing quite a lot. We need to know how the virus [is evolving] to keep up with our enemy
The scientists are investigating whether Ebola has become more contagious and if it is close to becoming AIRBORNE.
"We know the virus is changing quite a lot," said human geneticist Dr Anavaj Sakuntabhai.
"We need to know how the virus [is evolving] to keep up with our enemy."
A mutation to allow the spread of Ebola through inhalation is one of the biggest and most common fears.
Airborne infection has so far only been proven possible in strict laboratory conditions, but only between pigs to primates.
Institut Pasteur virologist Noel Tordo said: "At the moment, not enough has been done in terms of the evolution of the virus both geographically and in the human body, so we have to learn more. But something has shown that there are mutations.
"For the moment the way of transmission is still the same. You just have to avoid contact [with an Ebola sufferer]"
"But as a scientist you can't predict it won't change. Maybe it will," he admitted.
French researchers are analysing hundreds of blood samples from Ebola sufferers in Guinea
Ebola is currently spreading through three nations in West Africa
The warning comes as the number of new confirmed cases dropped below 100 for the first time since June last year and tests on a vaccine proved it was safe to use.
One of the biggest changes detected by the French scientists is the increase in asymptomatic patients – people infected and contagious but who don't exhibit any of the known symptoms of the deadly virus.
The French researchers are analysing hundreds of blood samples from Ebola sufferers in Guinea.
Dr Sakuntabhai explained: "We've now seen several cases that don't have any symptoms at all, asymptomatic cases.
"These people may be the people who can spread the virus better, but we still don't know that yet.
"A virus can change itself to less deadly, but more contagious and that's something we are afraid of."
The research is critical in tracking ongoing changes in how the virus responds to vaccines.
Professor James Di Santo, who works as an immunologist at the Institut Pasteur, said: "We've seen now this is a threat that can be quite large and can extend on a global scale.
"We've learned this virus is not a problem of Africa, it's a problem for everyone."
"This particular outbreak may wane and go away, but we're going to have another infectious outbreak at some point, because the places where the virus hides in nature, for example in small animals, is still a threat for humans in the future," he added.
"The best type of response we can think of … is to have vaccination of global populations."
The Institut Pasteur in France, is the lab responsible for first identifying the outbreak
Royal Free Hospital in London successfully cured nurse Pauline Cafferkey
Ebola is currently spreading through three nations in West Africa.
More than 22,000 people have been infected with Ebola – with some 8,795 dead in Guinea, Sierra Leone and Liberia.
Although there is currently no approved treatment for the fatal virus a number of experimental drugs are being developed.
Survival can often depend more on the strength of the sufferer's immune system than anything medical science is currently able to do.
The number of new Ebola cases last week was the lowest recorded tally since June 2014, WHO has reported.
Many believe the drop could signal the start of a gradual decline in the epidemic with Liberia, one of the worst hit nations, reporting less than one death per day during the past three weeks.
However the mutating infection is continuing to spread in Guinea which has suffered a resurgence – with reported cases increasing by a third in the last seven days.
This morning British medics announced results from an early Ebola vaccine trial, which uses a single Ebola gene carried in a harmless chimpanzee cold virus to trigger an immune response.
Trials conducted at Oxford University paves the way for a vaccine, jointly developed by GlaxoSmithKline (GSK) and the US National Institutes of Health (NIH), to be further tested on patients in West Africa.
Initial results were said to be a "tad disappointing" but show that the drug is safe to use.
Britain has successfully treated two patients suffering from Ebola, including most recently nurse Pauline Cafferkey, 39, who was discharged from the Royal Free Hospital, in London earlier this month.
The fatal virus is classified as a Category A bioterrorism agent by the US federal government body Centres for Disease Control and Prevention – meaning it has the potential to be weaponised and used in biological warfare.