Scientists are not 100% certain and cannot rule out that ebola mutation events would not lead to increased spread throughout the world. The real concern for epidemic levels of disease could be from transmission of airborne droplet particles. Theoretically, coughing or sneezing particles could stay airborne for hours exposing more potential individuals by even inhalation routes.  A common example of this occurs with influenza virus.  A vaccine approach for the masses would be ideal for this virus.  Look for research data in early 2015 from patients currently in research trials to determine the vaccine candidates safety and effectiveness.  For now, the implementation of FDA approved screening tests and isolation policies for high-risk individuals traveling from these Ebola disease- burdened areas of Africa are prudent and warranted to protect us from becoming infected.

“Dr. C.J. Peters, who battled a 1989 outbreak of the virus among research monkeys housed in Virginia and who later led the CDC’s most far-reaching study of Ebola’s transmissibility in humans, said he would not rule out the possibility that it spreads through the air in tight quarters.”

http://www.latimes.com/nation/la-na-ebola-questions-20141007-story.html#page=1