In the race to stop the Ebola virus in its tracks, a vaccine that would help prevent people from contracting the deadly disease would be a powerful weapon.
Yet a vaccine still seems far off, even though global health officials are urging countries and companies to fast-track efforts to develop one, without compromising safety and effectiveness.
And there's the rub. Safe and effective vaccines are difficult and expensive to develop in the best of times. That process is more difficult in the midst of a growing health crisis.
Even the medicines being tested to treat a patient already diagnosed with Ebola offer no easy solutions.
Thomas Eric Duncan, the Liberian man who is undergoing treatment for Ebola and listed in serious condition in Dallas, won't be getting the experimental drug ZMapp used on several international aid workers and medical staff, including at least two other Americans.
That's because the company that makes ZMapp, Mapp Biopharmaceutical, has run out of supplies.
That's prompted U.S. government officials to try and ramp up production of ZMapp through a small biotech company in Texas.
All this just highlights how difficult it is to create new medicines to stop deadly threats like Ebola, said Dr. Pascal James Imperato, dean of the School of Public Health at SUNY Downstate Medical Center.
"It would be great to have a vaccine but it takes time to develop these treatments and there are the technical hurdles like testing to go through," Imperato said. "It's just not that easy to make them."
Imperato added that even coming up with a vaccine may not do the trick. That's because Ebola has so many mutating strains, making it much more difficult to find one drug that fits all.
The fact that Duncan's case—the first diagnosis of Ebola in the U.S.—has received so much attention, could put more pressure on finding a vaccine and might do more harm than good, said Dr. Robert Quigley, U.S. medical director and senior vice president of medical assistance for International SOS.
"We have to make sure a vaccine works," Quigley said. "The side effects could be more harmful than realized."