Researchers at Institut Pasteur, a French institute, said that the Ebola virus is mutating and the scientists are now trying to analyze if the mutation has made the virus more contagious. Researchers at the institute, which first identified the outbreak last March, said that they will test several blood samples from Guinean patients to know if the mutation will make the virus more dangerous than it already is in its current form.

The latest warning comes even as the number of confirmed new cases dropped to below 100 for the first time since June last year. Over 22,000 people, mostly in West Africa, have been infected with the virus. 

The potential for the Ebola virus to become more contagious increases as it has a high mutation rate, being an RNA virus like Influenza and HIV, BBC reported. Until now a person who is suspected of being exposed to the virus was being held in isolation period for 21 days to check for symptoms of the virus. However, doctors are now reportedly claiming of having dealt with patients who have not shown any symptoms.

"We know the virus is changing quite a lot," human geneticist Dr. Anavaj Sakuntabhai, said, according to BBC, adding: “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."

However, Professor Jonathan Ball, a virologist at the University of Nottingham, said, according to BBC, it was not yet confirmed whether more people were actually not showing symptoms in the current outbreak. "We know asymptomatic infections occur … but whether we are seeing more of it in the current outbreak is difficult to ascertain," he said, adding: "It could simply be a numbers game, that the more infection there is out in the wider population, then obviously the more asymptomatic infections we are going to see."

One of the major concerns regarding the virus is that it may become airborne, but scientists say the method of transmission of the disease currently remains the same. 

"For the moment the way of transmission is still the same. You just have to avoid contact [with an Ebola sufferer]," Noel Tordo, a virologist at Institut Pasteur said, according to Daily Express, adding: "But as a scientist you can't predict it won't change. Maybe it will."

The institute is currently working on two vaccines and is hoping to get them to the stage of human trials by the end of 2015, BBC reported. One of the vaccines is reportedly a modification of a measles vaccine. If proved successful, the vaccine could potentially protect against both measles and Ebola.