A researcher with the British pharmaceutical giant GlaxoSmithKline says that an Ebola vaccine may not be ready for commercial use until late 2016.
"We have to be able to manufacture the vaccine at doses that would be consistent with general use and that's going to take well into 2016," Doctor Ripley Ballou, head of GSK's Ebola vaccine research unit, told BBC radio in an interview aired on Friday.
"I don't think this vaccine should be seen as the primary answer to this particular outbreak but we certainly hope that this vaccine could be used to prevent future outbreaks.
"Unfortunately it's not going to be as quickly as we would like," he said, adding: "In retrospect we should have pulled the trigger earlier."
Ballou said data on the vaccine's efficacy and safety would not be available before the end of 2015.
"In order for the vaccine to be used we have to have data on its safety and its efficacy and those data will not be available before the end of 2015," he said.
He added that the whole process was "incredibly accelerated" as vaccine development would normally take seven to 10 years.
GSK's is one of two vaccines along with one by US group NewLink Genetics that the World Health Organization has been focusing on and it has helped accelerate clinical trials.
Some clinical trials of the GSK vaccine have begun in the United States and Britain and the WHO has said that around 10,000 doses of the vaccine should be available by early 2015.