The virus can not pass easily between humans, but if it were to mutate and acquire that ability, it could potentially cause a pandemic. However in 2011 two researchers performed experiments on the virus that created a highly transmissible form.
One of the greatest concerns over this kind of research with a deadly virus is the possibility of accidental release by a researcher who becomes infected or some sort of spill or containment accident.
Now, the U.S. government has announced new policies for reviewing such potentially risky research before it gets funded. However the US is only one of many countries with labs working on this kind of scary stuff.
We need to be worried.
Credits: Image of virus from freedigitalphotos.net